CHAPTER 4 Valarie V. Tynes1, Leslie Sinn2,3, and Colleen S. Koch4 1 Premier Veterinary Behavior Consulting, Sweetwater, USA 2 Veterinary Technology Program, Northern Virginia Community College, Sterling, USA 3 Behavior Resident in Private Practice Training, Hamilton, USA 4 Lincoln Land Animal Clinic, Ltd, Jacksonville, USA Behavior can change as a result of medical issues or physiological changes. If shelter staff and veterinarians identify those potential behaviors that may have an underlying medical condition and have some insights on management, then dogs and cats can receive superior care from intake to adoption. As it is not proper today to cure the eyes without the head nor the head without the body, so neither is it proper to cure the body without the soul, and this is the reason why so many diseases escape Greek physicians who are ignorant of the whole. (Socrates) In order to provide optimal medical care for any animal, it is imperative that we first move beyond the paradigm where we attempt to separate “medical” conditions from “behavioral” conditions. All medical conditions will result in some behavioral change (American Psychiatric Association 2013). Many of these are the most basic of signs and symptoms that all veterinarians are taught to look for, such as the lethargy and anorexia associated with many illnesses. Conversely, every behavior is a result of neurochemical action at the molecular level in the nervous system and thus cannot ever be completely separated from the physiological (Figure 4.1). While some behavioral changes can be associated with organic diseases, such as space occupying masses in the CNS, or the changes that occur as a result of infection and/or inflammation, other behaviors can be a result of dysregulation at the neurophysiological or neurochemical level—problems that we still have much to learn about. It is hoped that with advancing technology, our understanding of the neurophysiologic basis of behavior will continue to improve. Figure 4.1 An image depicting the interconnectedness of medical problems, behavioral health, the environment, and stress. No single factor stands alone. One factor cannot be affected without another factor also being affected to some degree. Historically, a medical model has been used as an approach to problem behaviors. While this approach can be broadly used to categorize behavioral problems and improve communications between caregivers and the health care team, it is important to keep in mind that these categories are purely descriptive and rarely reflect a knowledge of the cause, mechanism, or neurobiology underlying the behavior (American Psychiatric Association 2013). Some behaviors may reflect a dysregulation or disruption of the neurological system and may thus be considered truly malfunctional, as the medical model suggests. Other behaviors may represent an animal’s attempt to adapt to an environment to which adaption is not completely possible and should be considered maladaptive (Mills 2003). A thorough understanding of the environment in which the animal developed and within which it currently lives, as well as knowledge of the normal species typical behaviors for the animal in question, will be critical to developing a management and/or treatment plan for the individual exhibiting maladaptive or malfunctional behaviors. A third category that will not be covered in this chapter is the normal adaptive behaviors of animals that are simply inconvenient or problematic for their caretakers. Both maladaptive and malfunctional behaviors can develop secondary to other underlying disease processes. Alternatively, other disease processes may contribute to malfunctional and maladaptive behaviors. Many individuals will simply differ in how readily they react to stimuli, the degree to which they respond, and in how long they stay emotionally aroused. These differences may often represent normal individual variations in temperament and are also effected by an individual’s experience during development. Thus the line between normal and abnormal behavior may not always be a clear one. It is well understood that dogs and cats continue to express many of the behavioral patterns expressed by their wild ancestors. The behaviors typical of sick animals represent a highly adaptive behavioral strategy, so it is not surprising that many of these behaviors have been retained in spite of domestication. Initially, most sick animals will display varying degrees of lethargy and anorexia. In many cases, this occurs due to the development of a febrile response. These behaviors, often viewed by caretakers as abnormal, are in fact normal and serve a beneficial purpose for the affected animal (Box 4.1). Fever has the effect of assisting the animal to combat infectious disease by potentiating numerous immunologic responses (Hart 2010, 2011). It also produces a body temperature that is inappropriate for the growth of most pathogenic organisms. The same physiologic response that produces the fever results in anorexia, and the animal, with no desire to move about in search of food or water, will save energy needed to make up for the increased metabolic cost of the fever. Due to the fact that the febrile animal feels cold, they are likely to lie curled up. This reduces the body surface area and decreases heat loss by convection and radiation. Piloerection is also likely in sick animals, as it provides some increased insulating ability (Hart 2010). The lethargic, ill animal will spend less time grooming, so a coat that appears dirtier or oilier than normal may be an indication of illness. Grooming requires movement, and thus expenditure of energy, and oral grooming leads to a not insignificant amount of water loss, especially critical to a febrile animal attempting to conserve water, energy, and body heat. There will be some variation in how rapidly these behavioral changes set in and in the degree to which they appear, depending upon the pathogen involved. Some diseases will cause a rapid and severe onset of lethargy and anorexia, while others may develop more slowly and the behavioral signs may be less obvious. The status of each individual’s immune system may also affect the degree of illness experienced and thus the degree of behavioral change. Grooming behavior has evolved in mammals to serve a variety of purposes, depending upon the species. These behaviors may spread natural body oils throughout the coat, contributing to coat health, thermoregulation, and effectively decreasing ectoparasite loads (Hart 2011). The behaviors associated with avoiding fecal contamination (den sanitation behavior) are highly adaptive as they usually help to decrease the consumption of parasite larvae. Most species will not normally feed on a dead conspecific, again an adaptive behavior that likely prevents the spread of many pathogens. Saliva contains a variety of antibacterial and wound-healing substances, so that the predisposition for animals to lick body parts and wounds is likely an evolved behavioral tool for decreasing the incidence of infection (Hart 2011). When animals fail to practice any of the behaviors described above, it should serve as a warning sign that something is wrong. Cats often seem to be even better than dogs at hiding their illnesses, possibly due to their unusual position of being both predator and prey, depending upon the environment. Anorexia is often the first sign noted by owners of sick cats. The fastidious nature of the cat contributes to their ability to mask signs of disease. For example, if they have diarrhea, they are likely to clean themselves, removing all signs of the mess, until the time when they become too ill to do so. The more sedentary and nocturnal nature of the cat may also allow inactivity due to illness to be overlooked until it becomes most severe. However, due to the fastidious nature of the cat, an unkempt hair coat should be immediately noted and a possible cause investigated since the cat must be either ill or injured or somehow impaired in its movement in order for it to stop grooming itself. One recent study demonstrated that the presence of unusual external events will increase the risk of sickness behaviors in cats (Stella et al. 2011). In one study, where cats were exposed to multiple unpredictable stressors including exposure to multiple unfamiliar caretakers, an inconsistent husbandry schedule, and discontinuation of play time, socialization, food treats, and auditory enrichment, cats demonstrated a higher incidence of sickness behaviors (Stella et al. 2013). These behaviors included increased vomiting (Stella et al. 2013), decreased food intake, avoidance of elimination for 24 h, and elimination outside the box (Stella et al. 2011). A variety of different studies have suggested that monitoring of sickness behaviors in the cat may be an excellent additional means of evaluating feline welfare and that the cats’ behavior is a more reliable indicator of their level of stress than their physiological responses (Stella et al. 2013). Nowhere else is the interplay between behavioral and physical health more apparent than when looking at the role that stress plays on every aspect of health. Increasingly, science is uncovering the myriad of different ways in which stress affects living organisms at every stage of development. Much controversy exists about how to actually define stress, so for the purpose of this chapter stress (or stressors) will be defined as any physical, chemical, or emotional force that disturbs or threatens homeostasis and the accompanying adaptive responses (the stress response) that attempt to restore homeostasis. While the physiological events that occur during an acutely stressful event are intended to be adaptive, and in most cases, they succeed in helping an organism maintain homeostasis by adapting to the stressor, when stress is chronic and unremitting, a variety of physiological events can conspire to actually damage the overall health and well-being of the organism. Thus, in the long term, the stress response can be maladaptive. There are two primary components of the stress response involving two different endocrine systems. The first is the sympathetic nervous system response. Within seconds of perceiving a stressor, the sympathetic nervous system begins secreting norepinephrine and the adrenal medullae begin secreting epinephrine. This begins to prepare the body for “fight or flight.” The second system is the hypothalamic-pituitary-adrenal (HPA) axis, generally believed to be the body’s primary stress responsive physiological system (Hennessy 2013). When the HPA is triggered, the hypothalamus releases corticotrophin releasing factor that triggers the release of adrenocorticotropic hormone from the pituitary gland. The pituitary gland then stimulates the release of glucocorticoids from the adrenal cortex. Several other hormones, including prolactin, glucagon, thyroid hormones and vasopressin are secreted from various other endocrine organs. The overall effect of all of these circulating hormones is to increase the immediate availability of energy, increase oxygen intake, decrease blood flow to areas not critical for movement, and to inhibit digestion, growth, immune function, reproduction, and pain perception. In addition, memory and sensory functions are enhanced. Essentially, the goal of all of this physiological activity is to make more energy available for immediate use and to put on hold any and all processes that are not involved in immediate survival. Acute stress has been shown to enhance the memory of an event that is threatening (McEwen 2000). This is clearly adaptive if it allows the organism to remember with great clarity some dangerous thing or place that it should avoid in the future. Knowledge of this tendency should increase animal handlers’ awareness of how their behavior and actions can affect an animal and ultimately lead to long-term problems with an animal’s behavior. If the stress response continues, for whatever reason, cardiovascular, metabolic, reproductive, digestive, immune, and anabolic processes can all be pathologically affected. The results can include myopathy, fatigue, hypertension, decreased growth rates, gastrointestinal distress, and suppressed immune function with subsequent impaired disease resistance. Chronic stress can even lead to structural and functional changes in the brain, and when extreme conditions persist, permanent damage can result (McEwen 2000). It is believed that when dealing with chronic stress, the HPA becomes dysregulated and the various components of the system may no longer respond in the predicted fashion. For example, in some cases, chronic stress results in adrenal hypertrophy and elevated levels of glucocorticoids, while adrenocortical stimulating hormone (ACTH) levels remain unchanged. At this point, the dysregulation results in an HPA axis that is no longer able to respond appropriately to future stressful events, and measurements of glucocorticoid levels may become less meaningful (Hennessy 2013). Stress can arise from a variety of different sources, both physiological and psychological. Physical stress can be caused by hunger thirst, pain, exposure to extreme temperatures disease, illness, and sleep deprivation. Psychological stressors can arise from exposure to novelty, unpredictable environments, social conflict, and constant exposure to fear or anxiety provoking stimuli and situations leading to frustration or conflict. A lack or loss of control is another important psychological stressor. In fact, novelty, withholding of reward, and the anticipation of punishment (not the punishment itself) have been found to be the most potent of all psychological stressors (McEwen 2000). A variety of different means have been used in an attempt to measure physiological stress, including but not limited to measuring glucocorticoids and their metabolites in hair, urine, feces, blood, and saliva. Glucocorticoids in blood and saliva do appear to measure the condition of the animal at that moment, whereas glucocorticoids in urine, feces, and hair reflect the condition of the animal over a longer time frame (Hennessy 2013). ACTH and luteinizing hormone releasing hormone stimulation tests have also been used to measure adrenal and pituitary sensitivities, respectively, and one study demonstrated increased HPA responsiveness and reduced pituitary sensitivity occurring in the face of chronic stress (Carlstead et al. 1993). The altered responsiveness was suggestive of HPA dysfunction. A decrease in peripheral lymphocyte numbers and an increase in neutrophil numbers along with an increased N:L ratio is another well-documented response to glucocorticoid release and has been proposed as another reliable method for evaluating the stress an animal may be experiencing (Davis et al. 2008). Any single individual’s response to stress will vary as a result of several different factors such as genetics, temperament, experience, environment, and learning. For example, cats not socialized to people have been shown to be more likely to experience high levels of stress when exposed to people in a shelter setting (Kessler & Turner 1999a). Experiences during the first weeks of life have been shown to have profound effects on an animal’s ultimate ability to cope with stress (Foyer et al. 2013). The individuals’ perception of stress, which will also vary based on experience, is ultimately the most important factor that influences the effect of stress. Many dogs in animal shelters are likely stressed as soon as they enter the shelter. For a social species such as the dog, separation from a familiar social figure is very stressful (Jones & Josephs 2006; Horváth et al. 2008), so dogs that enter the shelter due to having become lost or having been relinquished by their owners are likely already experiencing this significant social stress. Other stressors that may be present in the shelter environment include loud noises, restraint and unpredictable handling, confinement to a small area, and possibly being forced to eliminate on unfamiliar surfaces and/or in their living space. Sounds and odors associated with the stress and aggression of other dogs are present, routines are changed, and they are immersed in a novel environment and surrounded by novel stimuli. All of these are things that have been found to contribute to stress in the sheltered dog, and studies have shown that the average shelter dog does in fact have higher levels of circulating cortisol than pet dogs that were sampled in their homes (Hennessy et al. 1997). Some studies of shelter dogs have found that circulating levels of cortisol return to normal within days to weeks but others have found that HPA axis dysregulation develops in some shelter dogs (Hennessy 2013). In dogs, behavioral signs of acute stress may include increased body shaking, crouching, oral behaviors, yawning, overall restlessness, and a lowered body posture (Beerda et al. 1998). Additional studies suggest that a lowered body posture, increased autogrooming, paw lifting, vocalizing, repetitive behavior, and coprophagy may all be associated with chronic stress in kenneled dogs as well (Beerda et al. 1999). Confined cats have been shown to be stressed by unpredictable handling and husbandry routines (Carlstead et al. 1993). Increased density of group-housed cats has been shown to be positively correlated with stress levels (Kessler & Turner 1999b). Shelter cats exhibiting higher stress scores have been shown to be at a higher risk of upper respiratory tract infections (Tanaka et al. 2012). Decreased food intake and weight loss have also been associated with stress in shelter cats (Tanaka et al. 2012). When stressed, cats have been shown to display less play and active exploratory behaviors and spent more time awake and alert but attempting to hide. When cats are unable to hide, they experience more stress (Carlstead et al. 1993). Behavioral apathy, vocalization, escape behaviors, and aggressive behavior have also been considered indicators of stress in kenneled cats (Kessler & Turner 1997). One study reported that feigned sleep may be a coping mechanism seen in stressed shelter cats (Dinnage 2006). An increased need for sleep has been demonstrated in both humans and animals exposed to physiological or biological stress (Rampin et al. 1991; Rushen 2000). This data suggests that while cats may appear to be the most relaxed of animals, they may in fact be suffering the highest levels of stress. Decreased activity and increased hiding and sleeping may be the best indicators of stress in cats. The stress level of most kenneled cats will decrease over the first few days to weeks with one study demonstrating that 2/3 of cats will adjust well within the first 2 weeks (Kessler & Turner 1997). The same study demonstrated that about 4% of cats maintained a high level of stress for the entire study period, suggesting that for a small segment of the feline population, housing in the shelter for any extended period may not be in the best interest of that individual (Kessler & Turner 1997). Recognizing the behavioral signs of pain in dogs and cats is a great challenge due in part to the fact that they are nonverbal. However, the very fact that they are nonverbal makes recognizing their pain an even more critical endeavor if we are to ensure that they experience good welfare while in our care. A number of problem behaviors can potentially occur in dogs and cats in response to pain. These can include irritability, aggressiveness, restlessness, excessive vocalization, changes in activity level, and an increase in anxiety related behaviors. Any abrupt changes in behavior can signal pain but they are especially noteworthy when occurring in a middle aged or geriatric animal. Pain in the shelter animal may be even more difficult to identify since caretakers may not have an extended period of time to become familiar with an individual and be able to determine what is normal or abnormal for that individual. To further complicate matters, objective signs of problems that could lead to pain that typically can be identified with a physical exam, radiographs, laboratory work, etc., may not always coincide directly with more subjective measures. Therefore behavioral signs may be the most important feature we should attend to and we should always keep in mind that if a procedure, injury or illness causes pain in humans, then it would be wise to assume that it will be painful in dogs and cats as well. Several studies have found that subjective behavioral measures can be used to identify pain in animals and subsequently evaluate the efficacy of treatment (Holton et al. 1998; Cloutier et al. 2005; Bennett & Morton 2009). However, much more research is needed in order to refine and validate some of the current methods. Since in a shelter situation, some diagnostic capabilities may be limited, anecdotal information suggests that when in doubt, a course of treatment with analgesics and/or anti-inflammatories may be warranted if a painful condition is suspected. Different dogs will manifest pain in different ways. Unfortunately, there is no single behavior that can be considered pathognomonic for pain and the absence of certain behaviors cannot be guaranteed to mean that the dog is not experiencing pain. Many behaviors considered to be typical of pain can also occur due to anxiety or fear. In addition, the presence of other diseases can change the appearance of pain behaviors. Behavioral responses to pain that may be seen in dogs can range from hiding and avoidance behaviors to aggressive facial expressions and body postures. Dogs may whine, attempt to bite or lick a painful area, or rub the painful area against walls or doors. Decreased social interactions in a previously friendly dog, increased vocalizations, changes in activity level or demeanor, and changes in temperament or mood should all be considered possible signs of pain or discomfort. A reluctance to move or to change position, especially once recumbent, can be indicative of pain. Alternatively, some dogs in pain will be more restless and frequently change position. Anorexia is one nonspecific sign of pain in dogs. In addition, heart rate, respiratory rate, and blood pressure can also be used to assess pain but ideally all of these parameters should be considered in conjunction with the more subjective signs, as they too are very nonspecific. Other signs of pain or discomfort associated with particular conditions will be covered under those systems later in this chapter. Some pain scales that have been found useful in evaluating dogs are the Glasgow Composite Measure Pain Scale and the Colorado State University Acute Pain Scale and these could readily be adapted for use in a shelter situation (Holton et al. 1998; Reid et al. 2007; Schiavenato et al. 2008) (http://www.gla.ac.uk/schools/vet/research/painandwelfare/downloadacutepainquestionnaire/, http://csuanimalcancercenter.org/assets/files/csu_acute_pain_scale_canine.pdf, http://www.vasg.org/pdfs/CSU_Acute_Pain_Scale_Kitten.pdf). Common behavioral signs of pain in cats include avoidance or flight response, restlessness or agitation, hunched posture, squinting eyes, reluctance to move, vocalization including purring, gait changes, decreased appetite, changes in grooming behavior, tail flicking, and changes in interactions with people. Pain can lower the cat’s tolerance for handling and lead to aggression when certain body parts are manipulated. Some cats with pain will avoid human approach completely, attempting to flee and/or becoming aggressive if attempts are made to move or lift the cat. In cats, several studies have shown that signs of pain and discomfort associated with degenerative joint disease commonly occur prior to the appearance of radiographic signs (Hardie et al. 2002; Clarke & Bennett 2006). Decreased walking, running, jumping, or climbing along with increased sleeping and less play are some of the more common signs associated with the pain of degenerative joint disease in cats. However, these signs can also be associated with impaired vision, a condition common to cats suffering from high blood pressure secondary to hyperthyroidism, renal disease, heart disease, or diabetes. Lameness due to arthritic pain is much less common in cats than dogs (Clarke & Bennett 2006). In addition, while palpation may be effective at determining when and where dogs are experiencing pain, cats are often resentful of palpation under normal circumstances, so response to palpation is unlikely to be diagnostic for pain or discomfort. When evaluating dogs and cats for pain, it is also important to be aware that there are different kinds of pain and altered sensation. Neuropathic pain has been defined as “pain arising as a direct consequence of a lesion or disease affecting the somatosensory system” (Shilo & Pascoe 2014). It is considered a chronic pain state that results from peripheral or central nerve injury and can be due to acute events such as amputation or systemic disease such as diabetes. As opposed to functional pain, neuropathic pain is believed to serve no purpose. Nociceptors are not involved but the mechanisms underlying the syndrome are unclear. The relief of neuropathic pain is generally considered extremely challenging. Phantom limb pain, where the patient perceives pain in a limb that is no longer present, has been described in 60–80% of human patients following amputation (Ramchandran & Hauser 2010; Vase et al. 2011) and it has been reported in animals (Shilo & Pascoe 2014). Similar pain has been reported after amputation of other body parts in humans and pre-amputation pain has been determined to be a risk factor for phantom pain in humans. This should be kept in mind as a possible outcome when dealing with animals since amputation is often indicated as the result of a fracture or neoplasia. The mechanisms underlying the development of phantom pain are poorly understood, but as is the case with other types of pain in animals, the possibility that they experience all types of pain similarly to humans should never be ignored. Other sensations that may also exist in animals include hyperalgesia, an exaggerated response to a painful stimuli due to a lowered pain threshold, and allodynia, a pain resulting from stimuli that would not normally be considered painful. An abnormal sensation, referred to as dysesthesia is an unpleasant, abnormal sensation to touch which is likely due to a lesion in the nervous system. Since animals cannot report what they are experiencing verbally, and limited diagnostic capabilities may prevent us from being able to clearly recognize these conditions in animal, it will be even more incumbent upon the caretaker to be extremely observant for signs of pain in animals. Many disease conditions are more likely to be associated with individuals in certain age groups. Table 4.1 lists some of these diseases and the age groups that they are more likely to be associated with. Table 4.1 Conditions likely to be associated with animals of particular ages. Adapted from Overall (2003). Reproduced with permission from Elsevier. © Elsevier. * Unless the dog has a well-documented history of rabies vaccination, rabies should always be considered in a dog presenting with acute behavioral change, regardless of age. Anxiety is the emotional response that occurs when there is the anticipation of future danger. What is critical for animal caretakers to be aware of is that the danger does not have to be real; it may be unknown or imagined. What is equally important is that when the animal perceives something to be dangerous or threatening that is what they will respond to emotionally. The physiological responses to feelings of anxiety are similar to the responses that are seen with fear. The animal experiencing anxiety may pace, pant, tremble, and salivate. Blood pressure, heart rate, and respiratory rate may increase and the pupils may dilate. The HPA axis may respond with corticosteroid release. Anxious animals may show avoidance behaviors such as hiding and they may be hypervigilant to stimuli in their environment. Other behavioral signs of anxiety include general behavioral arousal, irritability, and restlessness. Anxious animals may freeze and show tonic immobility responses or they may become more restless. Increased aggressive or threatening behavior may be seen and anxiety may result in sleep disturbances for many animals. Other visual cues that may be associated with feelings of anxiety include lowered body posture, lowered ears, and tucked tail. Anxious animals may lick their lips repeatedly or yawn and their facial features are likely to appear tense rather than relaxed and loose. Many of these behaviors can also be seen associated with particular medical conditions, further complicating some diagnosis. Like the stress response itself, anxiety responses should be adaptive; they should prepare the animal to avoid danger. Anxiety normally increases attentiveness to surroundings and stimulates risk assessment. However, as is the case with stress, when anxiety provoking stimuli occur frequently and/or are inescapable, then anxiety has the potential to lead to all of the long-term consequences seen when animals experience chronic stress. In addition, it appears that some individuals have behavioral dysfunction due to pathological anxiety and this results in maladaptive behavior. A definition for pathological anxiety has been proposed: “Pathological anxiety is a persistent, uncontrollable, excessive, inappropriate and generalized dysfunctional and aversive emotion, triggering physiological and behavioural responses lacking adaptive value. Pathological anxiety-related behaviour is a response to the exaggerated anticipation or perception of threats, which is incommensurate with the actual situation” (Ohl et al. 2008). Differentiating pathological anxiety from the situational anxiety that might be expected in an animal that has recently been introduced into a shelter situation will not be easy as the line between normal and abnormal is often vague. However, caretakers should remain aware that some animals will not adapt well to the shelter environment due to preexisting behavioral pathology. In addition, the behavioral pathology may predispose these animals to illness and poor welfare due to the chronic stimulation of the HPA axis and the animal’s inability to adapt to the changing environment. Lastly, anxiety can occur as a result of any disease process, pain, or discomfort, especially if it remains unidentified by caretakers and thus untreated. A variety of different neurological disorders have the capability of effecting behavior in a variety of different ways. While many neurological disorders are steadily progressive and thus will eventually present additional nonbehavioral signs, in many cases, behavioral changes will precede the appearance of other more severe neurological signs by weeks or even months. Storage diseases, neoplasia, inflammatory conditions, degenerative conditions, toxicosis, malformations, ischemia, and infections can all lead to changes in behavior. The location of a brain lesion will dictate the behavioral changes seen. The limbic system, whose structures lie deep within the brain, functions to control emotions and basic drives such as sexual activity, memory, anxiety, and feelings of pleasure. Damage to the limbic system can result in personality changes including fear and aggression. In other cases, seizures may result. The forebrain including the prefrontal area is the part of the brain associated with cognitive behavior, motor planning, thought, and perception. Forebrain lesions can also lead to changes in personality, temperament, or mood. A loss of previously learned behaviors and failure to recognize or respond appropriately to environmental stimuli may result from forebrain lesions. Lesions of the brain stem or forebrain may lead to changes in awareness or consciousness and mentation. Animals with brainstem lesions may demonstrate altered response to stimuli, dullness, stupor, and eventually coma (Lorenz et al. 2011). Intracranial neoplasia can be either primary or secondary, and depending on the location within the brain and the character of the tumor, brain neoplasia can result in several different behavioral changes. Primary brain tumors originate from cells within the brain and meninges and are more likely to result in insidious, slowly progressive effects, whereas secondary tumors resulting from metastatic disease will usually result in acute changes. The most frequently recognized sign of a brain tumor will be seizures, but other clinical signs such as changes in behavior and mentation, visual deficits, circling, ataxia, head tilt, and cervical spinal hyperesthesia may also develop. Reluctance to climb stairs, pacing, standing in corners, stumbling over objects, house soiling, and agitation may also be seen. Primary brain tumors in the dog may include meningioma, astrocytoma, neuroblastoma, oligodendroglioma, and ependymoma, to name a few. Dogs with brain tumors are usually presented with concurrent neurologic deficits, but one study found that when brain tumors developed in the rostral cerebrum, behavioral changes commonly occurred prior to the appearance of other neurologic deficits (Foster et al. 1998). These changes were described as dementia, aggression, and alteration in established habits. Many of the dogs in the study, but not all, also had seizures, but 72% of them had no neurological deficits on presentation. Neurological deficits eventually appeared in all cases, with some taking up to 3 months to appear (Foster et al. 1998). Meningiomas are one of the most common primary intracranial tumors in the dog comprising 33–49% of primary brain tumors. Glial cell tumors and pituitary tumors occur more often in brachiocephalic breeds. Overall the Boxer, Golden Retriever, Doberman Pinscher, Scottish Terrier, and Old English sheepdog appear to be more likely to develop brain tumors than the other breeds (LeCouteur 2011). While neoplasia in dogs younger than 6 months occurs less often, the brain is the second most common site for it to develop, so age alone cannot always rule out the possibility of a brain tumor. However, brain tumors occur most often in dogs over 5 years of age. Meningiomas are also the most common tumor of the feline brain. They are more likely to develop in cats over 9 years of age, but have been documented in cats as young as 1 year of age. There does not appear to be a breed predilection for meningiomas in cats but male cats may have a slightly higher likelihood of developing them. An unusually high incidence of meningiomas has also been documented in cats with mucopolysaccharidosis type I suggesting some genetic predisposition and a causal relationship between the two conditions. Behavioral changes in cats with meningioma have been documented as early as 1–3 months prior to diagnosis. Some geriatric cats with meningioma have been presented to their veterinarian with the owner complaint of “just not being themselves” (Sessums & Mariani 2009). Behavioral changes that have been reported included reluctance to play, episodic lethargy, and aggression. One owner reported apparent pain when touching her cat’s head 3 months prior to presentation with other clinical signs (Karli et al. 2013). Generalized seizures in dogs and cats are characterized by the animal falling into a laterally recumbent position with limbs rigid and paddling. They may or may not evacuate their bladder or bowels, they may vocalize, and will usually fail to respond if spoken to or touched. Focal seizures, however, are involuntary movements that may be localized to a single limb or part of the face. The animal experiencing a focal seizure may be somewhat responsive to other stimuli, but an aura and pre- and postictal phases may be present. These types of seizures can result in unusual behavioral presentations and can be difficult to diagnose. Focal seizures may be divided into motor and sensory type seizures. While motor seizures involve involuntary movement of one part of the body, sensory focal seizures may result in abnormal sensations such as tingling, pain, or visual hallucinations. Fly-biting or fly-snapping behaviors in some dogs may occur as a result of focal seizures with visual hallucinations. Unfortunately, electroencephalography must be performed at the time of the movement in order to confirm that it is a result of cerebral events. Obviously, this is extremely difficult to accomplish in veterinary medicine. Complex focal seizures (formerly known as psychomotor seizures) are focal seizures with alterations in awareness. Effected dogs may exhibit repetitive motor activities such as head pressing, vocalizing, or aimless walking or running (Berendt & Gram 1999). In some cases, complex focal seizures are manifested as impaired consciousness and bizarre behavior, such as unprovoked aggression or extreme, irrational fear (Dodman et al. 1992, 1996). Seizures are just one type of involuntary movement disorder in dogs and cats. Other forms of involuntary movements include myoclonus, tremor, intention tremor, dyskinesia, myokymia, neuromyotonia, and muscle cramps. Some of these movements are seen during periods of inactivity, which will help the clinician to recognize them as a movement disorder rather than a behavioral disorder. Those caused by cerebellar disease will occur during movement. Movement disorders are most likely to be caused by central nervous system disease such as lead toxicity or disease leading to CNS inflammation such as distemper virus infection. Metabolic diseases, such as hepatic encephalopathy, hypocalcaemia, and hypoadrenocorticism can also result in involuntary movements. Peripheral nervous system and musculoskeletal disorders may also result in involuntary movements. The pathophysiology underlying many of these syndromes remains poorly understood. If involuntary movements are limited to facial or head movements, then the possibility of a seizure disorder should be carefully considered. Cats with acute onset of partial seizure involving orofacial movements, such as salivation, facial twitching, lip smacking, chewing, licking, or swallowing, along with other behavioral changes, such as sitting and staring while motionless, and/or acting confused, have been diagnosed with a form of hippocampal necrosis (Pakozdy et al. 2011). The majority of these cats exhibited other neurological abnormalities on their first presentation. The exact etiology of this condition remains unclear but when the cat is responsive to antiseizure medication, quality of life can remain good for 1 year or longer (Pakozdy et al. 2011). Seizures in cats may also be associated with metabolic disease such as diabetes mellitus, hepatic encephalopathy, neoplasia, or meningoencephalitis (Barnes et al. 2004). Toxins may lead to personality changes in animals. Animals that have been intoxicated may present with central nervous system signs such as ataxia, stupor, seizures, or death. When signs are acute, a history of exposure is usually present. Illicit drugs such as cocaine, amphetamines, and marijuana are all drugs that if accidently ingested or inhaled can lead to central nervous system signs. Affected animals may exhibit varying degrees of hyperexcitability and hyperesthesia. Cocaine can also cause ptyalism, tachycardia, and increased muscle tone. Marijuana, when ingested by animals, usually results in ataxia and depression. Gastrointestinal signs have also been reported. Cats that consume hallucinogens have been reported to stare at walls or floors. Lead poisoning is one type of toxicosis that can present with a chronic course and no known history of exposure. Clinical signs usually involve either the central nervous system or gastrointestinal system. Most degenerative conditions of the neurologic system are heritable and will appear within the first few weeks to months of life. They include such conditions as cerebellar abiotrophy and lysosomal storage diseases. Cerebellar abiotrophy is a group of diseases believed to be inherited via an autosomal recessive mode of inheritance (Joseph 2011; Lorenz et al. 2011). The term abiotrophy, as opposed to hypoplasia, refers to the fact that previously-normal tissue begins to degenerate due to some intrinsic poorly understood abnormality. The condition can be minimal to rapidly progressive and varies to some degree by the breed affected. The condition has been reported in many breeds such as the Kerry Blue Terrier, rough coated Collie, Beagle, Samoyed, Irish Setter, Gordon Setter, Airedale, Finish Harrier, Bernese Mountain Dog, Labrador and Golden Retriever, Cocker Spaniel, Cairn Terrier, and Great Dane. Most puppies will be normal at birth, and beginning from 2 to 9 weeks of age they begin to show signs of cerebellar damage including ataxia, intention tremors, swaying, hypermetria, and a broad-based stance. The pups may demonstrate a lack of menace response even though the muscles associated with vision and the face are normal. They may present with head tremors or a head tilt and vestibular ataxia with nystagmus. At the extreme, pups may demonstrate the decerebellate posture that includes opisthotonus with extensor rigidity of the forelimbs but flexed hind limbs. While the age of onset is prior to 4 months in most cases, some animals may not show signs of disease until 2–2½ years of age. In some cases where the disease progression is minimal or very slow, some animals can learn to compensate for their disabilities. Drugs that have potentiating effects on neurotransmitters and neuroprotective agents may all be helpful in supporting these animals. Cerebellar abiotrophy can develop in the cat but has been less well documented. A single case report has described adult onset cerebellar cortical abiotrophy with retinal degeneration in a domestic shorthaired cat (Joseph 2011). If observed and examined carefully, the clinical signs associated with cerebellar degeneration should be readily differentiated from primary behavioral problems. Lysosomal storage diseases are relatively rare genetic defects that are characterized by progressive neuronal degeneration. They are most likely to occur in purebred animals with a history of inbreeding in the affected line. There are a variety of different forms of lysosomal storage diseases resulting in deficiencies of different hydrolytic enzymes leading to compromised cell function. Many of these diseases affect more than one body system including liver, kidney, spleen, pancreas and the skeleton, to name a few. Animals born with lysosomal storage diseases are normal at birth with clinical signs usually developing during the first year of life. Neuronal ceroid lipofusinosis is one of the storage diseases that can appear in adult animals. Case reports of Dachshunds with this condition have reported dogs developing the signs at 3, 5, and 7 years of age (Cummings & de LaHunta 1977; Vandevelde & Fatzer 1980). Early signs may include ataxia, disorientation, weakness and behavioral changes, but with time, affected individuals will suffer vision loss, progressive motor and cognitive decline, and seizures. Clinical signs will vary with the site of the brain inflammation and may be acute or chronic. A progressive, acute disease process is most typical however. Neurological deficits seen with inflammation may be diffuse, focal, or multifocal. Encephalitis or parenchymal central nervous inflammation may present with depression, stupor, coma, or other types of altered consciousness. Blindness, ataxia, seizures, and other behavioral changes may also be seen. In cats, intracranial meningitis is likely to result in general hyperesthesia, seizures, blindness, and behavioral changes. Granulomatous meningoencephalomyelitis is an idiopathic inflammatory disease of the central nervous system of dogs. Behavioral changes, seizures, and postural abnormalities may be seen. Box 4.2 lists some of the more common infectious and inflammatory conditions of the central nervous system. Inappropriate elimination is often a primary sign of an organic disease. Box 4.3 lists some of the more common reasons for dogs and cats to soil the house with urine. Regardless of the species, the first challenge will be to observe the animal and attempt to determine if it has voluntary control over urination some of the time, all of the time, or none of the time. Urination is a two-stage process involving the passive storage of urine in the bladder and the active voiding of urine from the urethra. The bladder is composed of smooth muscle, with the body of the bladder being referred to as the detrusor muscle. These smooth muscle fibers continue into the proximal urethra and form a functional internal urethral sphincter. The distal part of the urethra is composed of skeletal muscle and forms an external urethral sphincter. Micturition is thus under both autonomic and somatic control. The higher centers in the brain can exert final control over the micturition reflex in normal cases. Several different medical conditions can result in urinary incontinence where the animal has a lack of voluntary control over the passage of urine. Disorders of micturition are generally divided into two types, neurogenic and non-neurogenic. Some animals can experience urinary incontinence some of the time and still have voluntary control of urination at other times. This is most likely to occur with non-neurogenic conditions. One of the most common non-neurogenic disorders seen in dogs is hormone responsive incontinence. This condition may affect more than 20% of gonadectomized female dogs and results in incontinence most often when the animal is relaxed or asleep. Specifically it appears to occur secondary to urethral incompetence. Medium- to large-breed dogs appear to be affected most often, and obesity may increase the risk in gonadectomized female dogs. This condition is often treated successfully with reproductive hormones, alpha adrenergic agonists, or a combination of both. Imipramine and deslorelin have been used in some refractory cases. Neutering appears to increase the risk of urethral incompetence in large dogs (<20 kg) and neutering prior to 3 months may increase the risk of urinary incontinence in female dogs (Spain et al. 2004). Another condition which can lead to urethral incompetence and occasional dribbling of urine is urinary tract infection (UTI), inflammation, prostatic disease, or a history of prostate surgery. Animals with these problems should still have voluntary control of urination some of the time, but at other times, the urethral incompetence allows urine to dribble out and the animal cannot voluntarily stop the flow. Urinary bladder storage dysfunction can also result in frequent leakage of small amounts of urine. This can occur due to detrusor instability, UTIs, chronic inflammatory disorders, infiltrative neoplastic lesions, external compression, and chronic partial outlet obstruction. These animals too will have voluntary control over urination some of the time. Continuous dribbling of urine with the ability to urinate voluntarily can also occur in cases of ectopic ureters. Ectopic ureters are a congenital anomaly of the urinary system and are most commonly seen in juvenile female dogs. Some dog breeds, including Golden Retrievers, Labrador Retrievers, Siberian Huskies, Newfoundlands, miniature and toy poodles and some terriers appear to be predisposed (Berent 2011). The condition occurs infrequently in cats. Affected dogs will display urinary incontinence from birth and may have problems with chronic UTIs. Diagnosing the condition will require imaging such as cystoscopy, ultrasonography, contrast urography, or cystourethrovaginoscopy. Surgery is required to correct the condition. Dogs may also urinate due to excitement, submission, fear, or conflict. This is an involuntary action that occurs due to certain fear inducing or social stimuli. It is critical that the dog not be punished for the behavior. Even acting upset with the dog may increase its fear and conflict and thus make the problem worse. The problem is more likely to occur in young dogs and may be exacerbated by the presence of a full bladder during exciting or fear-inducing events. Young female puppies may be particularly prone to this problem due to poor sphincter control. If all people who interact with the dog greet the dog in a calm, nonthreatening manner, the problem will usually improve with age. When an animal is experiencing continuous dribbling of urine, without the ability to voluntarily control urination, it will most likely be a result of a neurogenic disorder such as lower motor neuron bladder. These conditions occur as a result of a lesion in the spinal cord and have a guarded to poor prognosis depending on the cause of the lesion (e.g. trauma, neoplasia, intervertebral disc disease). Lesions of the cerebellum or cerebral micturition center can also result in frequent, involuntary urination or leakage of small amounts of urine. When faced with a dog that is urinating inappropriately, consider that the dog may have been either incompletely house trained, may be experiencing true incontinence or may have a medical condition resulting in polyuria, and polydipsia or an inflammatory disease leading to an increased urgency and frequency of urination. Dogs with cognitive decline may begin house soiling simply due to a loss of previously learned behaviors. Aged dogs may need a more complete medical workup in order to rule out the large number of conditions that could be contributing to the behavior. Canine cognitive decline is an irreversible, neurodegenerative condition of aging dogs (and cats) and is a diagnosis of exclusion. In addition to house soiling, pets with cognitive decline, may also act disoriented, less interested in social interactions, have altered sleep-wake cycles and appear anxious or apathetic. Since both male and female dogs may lift their leg to urinate, unless there is a sudden change in the posture used for urination, attempting to determine whether the behavior is strictly elimination or urine marking will probably not be necessary in the context of the shelter. However, urine-marking behavior is more common in intact dogs and is considered a normal form of communication. When neutered animals mark, it is often due to situations involving conflict, frustration or anxiety. Regardless of the posture used for urination, several medical conditions will need to be ruled out. There are a variety of medical causes that may contribute to house soiling in the cat, and house soiling is likely one of the more common reasons for cats to be relinquished to shelters. If the cat is placed in a cage in a shelter, they are likely to begin using the litter box due to the limited lack of other preferable surfaces. However, some cats develop preferences for soft, absorbent substrates so they may choose to eliminate on any bedding that is placed in the cage. If the cat has an aversion to the litter box or the substrate offered in the box, then they may eliminate on newspaper or other surfaces in the cage. Unless the cat is demonstrating outward signs associated with urinary tract disease such as dysuria, stranguria, hematuria, or vocalizing while eliminating, it is possible that shelter staff may never know that house soiling is a problem for a particular cat. Cats housed in groups in rooms within the shelter may be more likely to demonstrate signs of house soiling. Fear or stress associated with interactions with unfamiliar cats may lead to urine-marking behavior and possibly even feline interstitial cystitis (FIC). If other cats block access to boxes, or a cat is simply too afraid to approach a box out of fear that it may be ambushed by another cat, then elimination outside the box may occur. Any elimination outside the box should be explored first for any underlying medical condition before making the determination that it is purely a behavioral problem. Any medical condition resulting in polyuria, polydipsia, incontinence, constipation, diarrhea, pain associated with elimination, increased frequency and/or urgency to eliminate, orthopedic disease making it difficult or painful to climb into a box, or declining sensory capabilities making it difficult to locate the box can all lead to elimination outside the box. Caretakers should also be aware that an aversion to the litter box may still exist long after the medical condition that promoted it is treated and eliminated. This can lead to problem behaviors that may be a result of a complex combination of both behavioral and medical conditions. Feline lower urinary tract disease (FLUTD) is a relatively common syndrome in the cat and often leads to the deposition of urine outside the box. FLUTD refers to disorders affecting the urethra and/or urinary bladder. Stranguria, dysuria, pollakiuria, hematuria, and urination outside the box are all signs that are consistent with FLUTD but numerous underlying etiologies are possible. Common etiologies include UTIs, uroliths, urethral plugs, idiopathic cystitis, bladder neoplasia, malformations, trauma, and urinary incontinence. Of these, most studies have found idiopathic cystitis to be the most common diagnosis when cats are presented with signs of FLUTD (Lekcharoensuk et al. 2001; Gerber et al. 2005; Saevik et al. 2011). Feline idiopathic cystitis is a diagnosis of exclusion. UTI should first be ruled out with a urinalysis, preferably using urine collected by cystocentesis. Cats are often treated unnecessarily with antibiotics based on a contaminated urine sample or the presumption of infection where none was present. One study demonstrated that clinical signs are in fact a poor predictor of UTI in cats and recommended urine culture as the best method for confirming the presence or absence of bacterial infections in cats (Martinez-Rustafa et al. 2012). The same study found that the best predictive factor for the presence of UTI was urinary incontinence (Martinez-Rustafa et al. 2012). UTIs are often associated with other underlying medical conditions and are rarely a primary disorder in cats. The presence or absence of uroliths should also be investigated using radiography, ultrasound, and/or cystoscopy if possible, since the absence of crystalluria does not exclude the possibility of uroliths. However, recognizing that these diagnostics are not always available to the animal shelter, empirical treatment for FIC might be initiated based on the absence of crystalluria and the lack of palpable stones in the bladder. If recovery is not seen within 2–3 days, with treatment, then the possibility of uroliths should be reconsidered. FIC is the term that is often used to describe feline idiopathic cystitis if the problem is recurring and characteristic signs of the disease are identified on cystoscopic examination (Buffington et al. 1999). The cause is currently unknown but a variety of different causative factors are suspected. FIC is believed to be analogous to interstitial cystitis in humans, a painful, inflammatory condition of the bladder in which increased urothelial permeability is a primary feature. Cats with FIC appear to have altered bladder permeability as well, and several studies have documented its association with stress (Buffington et al. 2002; Westropp et al. 2006; Stella et al. 2013). Cats with FIC appear to have increased sympathetic activity (Buffington & Pacak 2001; Buffington et al. 2002), be more sensitive to environmental stress, and have a decreased ability to cope with changes in their environment. Research continues to support the hypothesis that stress is associated with the development of FIC. One study, published by Cameron et al. (2004), found that cats with FIC were more likely to live in multi-cat households and be in conflict with another cat in the household. Clearly, a shelter environment has the potential to negatively affect the welfare of cats that are prone to FIC, and appropriate treatment will involve the treatment of symptoms as well as an attempt at identifying and reducing the stressors that may be affecting the cat. Several different treatments for FIC have been investigated and no single medication has been found to be consistently effective at treating the signs. Since FIC is likely a condition with a multifactorial etiology, then it is likely that treatment will be multifactorial as well. One study that evaluated multi-modal environmental modification (MEMO) in the management of cats with interstitial cystitis found that with MEMO there was a significant reduction in lower urinary tract signs, fearfulness, and nervousness (Buffington et al. 2006). MEMO was defined as changing the cat’s environment so as to decrease stress. Examples of these changes included avoidance of punishment, diet changes, techniques for increasing water consumption, changing to unscented clumping litter, improved litter box management, provision of increased structures for climbing and perches for resting and viewing, scratching posts, audio and visual stimuli when the owner was absent, increased client interactions with the cat, and identification and resolution of inter-cat conflict in the household. In addition to environmental management aimed at reducing stress, and feeding of a moist cat food instead of dry, other modalities that may be useful in the management of FIC include feline synthetic facial pheromones (Feliway), methods for stimulating water intake, analgesics and non-steroidal anti inflammatories to decrease pain during acute episodes, propantheline during acute episodes, glycosaminoglycans (e.g., pentosan polysulfate, glucosamine/chondroitin), and long-term amitriptyline for severe cases (Forrester & Roudebush 2007). The nervous system of the GI tract and the central nervous system are linked in a bidirectional manner by the sympathetic and parasympathetic pathways, resulting in what is referred to as the brain–gut axis. Due to this interrelationship, chronic stress can also have profound effects on the enteric nervous system (ENS). Severe life stressors have been shown to be associated with several GI tract conditions in humans and the effects in animal are just now being explored (Bhatia & Tandon 2005). Chronic stress has been demonstrated to decrease gastric emptying, increase intestinal contractility, increase gut permeability, reduce water absorption in the gut, disrupt normal electrolyte absorption, and increase the colonic inflammatory response (Bhatia & Tandon 2005). While less well documented, it is reasonable to expect that stress will have similar effects on the GI tract of dogs and cats. Behavioral signs that may be associated with gastrointestinal disease can include polyphagia, hyperphagia, polydipsia, copropahgia, and grass and plant eating. Oral behaviors such as frequent licking of surfaces (not self-licking), sucking, pica, gulping, and lip smacking behaviors may all be associated with gastrointestinal disorders. However, some partial motor seizures may be associated with behaviors like these, as well. Many gastrointestinal disorders can manifest with unusual behavioral signs. In one recent study where 19 dogs were examined due to frequent surface licking behaviors, 14 of the dogs were determined to have some form of gastrointestinal disease (Bécuwe-Bonnet et al. 2012). These included conditions such as delayed gastric emptying, irritable bowel syndrome, gastric foreign body, pancreatitis and giardiasis, to name a few. The unusual behavior of fly biting, considered by some to be a compulsive disorder has even been found to be associated with gastrointestinal condition such as gastroesophageal reflux (Frank et al. 2012). Many gastrointestinal conditions such as chronic diarrhea and vomiting have also been found to be closely associated with stress. Pica is the consumption of non-nutritive items such as fabric, paper, and plastic. In humans, pica also includes the consumption of food items for non-nutritive purposes such as coffee grounds and baking soda (Lacey 1990). It is associated with developmental disorders in people but can also be influenced by culture, developmental stage, underlying medical conditions, and other factors. The Diagnostic and Statistical Manual of Mental Disorders lists the following criteria for pica: developmentally inappropriate, not culturally sanctioned, present for more than a month, and clinically significant/severe (DSM-5) (American Psychiatric Association 2013). Pica may be evidence of a psychological disorder or of an underlying medical condition. Current thought is that pica is a symptom rather than a diagnosis and that multiple disease processes can have pica as a clinical sign. There is little research available involving companion animals and pica. However, a literature search for pica as a clinical sign links it to a variety of disease processes including portal caval shunts, iron deficiency anemia, pyruvate kinase deficiency, erlichiosis, gastrointestinal disorders, neurologic damage, FIP, and other medical conditions (Thomas et al. 1976; Black 1994; Goldman et al. 1998; Marioni-Henry et al. 2004; Kohn et al. 2006; Kohn & Fumi 2008; Bécuwe-Bonnet et al. 2012; Berset-Istratescu et al. 2014). Both cats and dogs can be affected. Pica has also been described in horses, cattle, sheep, and other domestic species (Houpt 2011). In rats and mice, pica has been found to be associated with gastrointestinal disturbances and may be an adaptive mechanism used to cope with gastrointestinal upset (Takeda et al. 1993; Yamamoto et al. 2002). There is some indication in the literature that oriental breeds of cats (Burmese and Siamese) may be represented in numbers higher than the general hospital population suggesting the possibility of an underlying genetic predisposition for pica (Blackshaw 1991; Bradshaw et al. 1997; Overall & Dunham 2002; Bamberger & Houpt 2006). To date, the evidence for a genetic basis is purely correlative. Some authors differentiate between oral behaviors and actual consumption while others describe consumptive behavior as a sequence or a spectrum of behaviors (Mason & Rushen 2008). When the sequence is disrupted through inappropriate husbandry, stress, or other factors, abnormal behavior can result. An example of this type of behavior is described in Doberman Pinschers with the majority showing sucking behavior and a smaller group also displaying pica (Moon-Fanelli et al. 2007). Underlying medical causes for pica should always be investigated and ruled out through appropriate diagnostics. A behavioral diagnosis of an abnormal repetitive disorder is made by excluding all other possible medical conditions. If financial constraints limit testing, a clinical trial with appropriate gastrointestinal protectant drugs is indicated prior to using any kind of psychoactive substance. Behavioral enrichment is indicated and behavior modification can be attempted (Blackshaw 1991). There is a single documented case study that successfully utilized behavior modification to diminish the occurrence of pica in a cat (Mongillo et al. 2012). In humans, the relationship between skin disease and mental health has received much attention in the past decade. The skin and the central nervous system are both derived from the embryonic ectoderm and they share many of the same hormones, neuropeptides, and receptors. Many of these substances are involved in neurogenic inflammation, pruritus, and pain sensation and stress can alter their release. A substantial number of chronic dermatoses in humans have been shown to be heavily influenced by stress. It has been estimated that in as many as one-third of the humans with skin disease, the condition is complicated by significant psychosocial and psychiatric morbidity. Patients with atopic skin disorders have also been shown to have a higher prevalence of anxiety, depression, excitability, suicidal ideation, and a decreased ability to cope with stress. While many of these emotions may be impossible to confirm in our non-verbal patients, it is logical to assume that stress has the potential to cause similar pathophysiologic responses that perpetuate the itch-scratch cycle. Cases of dogs with pyoderma and pruritic skin disease associated with psychogenic factors have been reported (Nagata et al. 2002; Nagata & Shibata 2004) and more research is needed in order for us to have a better understanding of psychogenic dermatological problems in dogs and cats. For that reason, the clinician should remain aware that many skin conditions may be potentially exacerbated in the stressed shelter animal. While no study has been able to confirm a link between pruritus and increased irritability and aggression, it should always be kept in mind that any physical discomfort has the potential to increase irritability and aggression in a dog or cat. Acral lick dermatitis (ALD), also sometimes referred to as acral lick granuloma, is primarily a dermatological syndrome that is a result of self-trauma. While some individuals may begin licking their leg to excess due to anxiety, frustration, or conflict, often referred to as displacement behavior, studies have found that many other underlying causes for these lesions are possible. Pruritus due to allergies, orthopedic pain, trauma, neoplasia, bacterial pyoderma, and fungal infections are just a few possibilities. Once a dog begins to lick and causes an open lesion, they will continue to lick it, no matter the original cause. When presented with a patient with ALD, a complete medical workup aimed at identifying the underlying cause is ideal. At the very least, deep tissue cultures should be taken and appropriate antibiotic therapy initiated. One study has demonstrated that the superficial bacterial population varies significantly from the deep bacterial population in these lesions (Denerolle et al. 2007). In addition, more than half of the bacterial populations isolated were resistant to the antibiotics typically used to treat skin infections in dogs (Shumaker et al. 2008). Antibiotic therapy must be continued for at least two weeks after resolution of the lesion. Physically preventing the dog from licking the lesion may be necessary to ensure resolution. This may be accomplished with the use of e-collars, bandages, socks, body suits or leggings, depending on what the individual patient tolerates. Other ancillary medications aimed at breaking the itch-scratch cycle may be helpful including but not limited to glucocorticoids and antihistamines. Once the lesion is completely healed, attention will need to be paid to the patient in order to determine if they continue to lick at the legs. In the experience of these authors, ALD is rarely a primary behavioral problem. If that is suspected, then the patient needs to be fully evaluated for other signs of fears or anxieties such as noise sensitivities or phobias, barrier frustration, or separation anxiety as it is unlikely that ALD would exist as a primary behavioral problem without one of these comorbid conditions. Grooming is a common displacement behavior, and the dog who is most stressed about the strange sights, sounds, and smells of the shelter, as well as the sudden change in its living arrangement and separation from familiar people, may be inclined to exhibit displacement grooming to the extent that it develops or worsens an existing ALD. When placed in situations of frustration or conflict, some animals will show displacement behaviors, and grooming is commonly seen as a displacement behavior in many species. Psychogenic alopecia
The relationship between physiology and behavior in dogs and cats
General concepts of the relationship between medical and behavioral issues
Recognizing the behavior of the sick animal
Cats
The role of stress
Dogs
Cats
The behavior of pain
Dogs
Cats
Neuropathic pain
Common medical conditions resulting in behavioral signs
Age group
Common conditions
<9 months of age
Congenital hydrocephalus
Lissencephaly
Lysosomal storage diseases
Viral, fungal, protozoal, and bacterial encephalitis, e.g., distemper and FIP encephalitis, and *rabies
Trauma
Toxicity, primarily lead
Hypoglycemia
Hepatic encephalopathy due to portosystemic shunt
Congenital defects and metabolic disease
Thiamine deficiencies
9 months to 5 years
Distemper/FIP encephalopathy
Viral, protozoal, or fungal encephalopathies
Steroid responsive meningoencephalitis
Granulomatous meningoencephalitis
Trauma
Toxicity
Hypoglycemia
Hepatic encephalopathy due to acquired hepatopathy or portocaval shunt
Other acquired metabolic disease
Acquired epilepsy
Cerebral neoplasia
>5 years of age
Distemper/FIP
Steroid responsive meningoencephalopathy
Granulomatous encephalopathy
Trauma
Toxicity
Hypoglycemia (insulinoma)
Hepatic encephalopathy due to acquired hepatopathy
Other metabolic disease
Acquired epilepsy
Cerebral neoplasia
Anxiety disorders
Neurological disorders
Neoplasia
Dogs
Cats
Seizures
Cats
Toxicosis
Degenerative conditions
Inflammatory conditions
Urogenital disorders
Urinary incontinence
Dogs
Cats
Gastrointestinal disorders
Pica
Dermatological disease
Acral lick dermatitis
Overgrooming
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