16.1.1 Environmental Stressors

Many studies have researched how the structure, complexity, and interactivity of environments have effects on the behavior and health of confined animals (Morgan and Tromborg 2007). Potential environmental stressors for cats in confined settings include:

• Overcrowding
  
• Sounds, smells, and sights of unfamiliar dogs and cats as well as other foreign smells
  
• Loud and startling noises
  
• New experiences
  
• Diminished control over and intrusion into personal space
  
• Unfamiliar surroundings
  
• Unpredictable routines
  
• Unnatural social situations.

New environments can cause anxiety, fear, and stress in cats. Being confined, particularly in high‐density environments, heightens the problem (Arhant et al. 2015; Kessler and Turner 1999b; Ottway and Hawkins 2003). While some animals express stress through defensive or destructive behavior, confined cats with elevated behavioral stress scores show stress through inhibited or withdrawal behavior (Stella and Croney 2016). In this case, inactivity and the inhibition of normal behaviors such as self‐maintenance (decreased feeding, grooming, and elimination and increased feigned sleeping, meaning stress‐induced, fake sleeping) as well as the inhibition of exploratory and play behaviors are signs of compromised welfare (Carlstead 1993; McCune 1994; Ottway and Hawkins 2003; Rehnberg et al. 2015) (see Box 16.1). Cats with illness may modify their behavior in a similar way (Rochlitz 1999), so in a shelter setting the early recognition of lack of activity and normal behavior are critical in the prompt recognition and differentiation of medical and behavioral concerns. In addition, signs of stress such as inactivity may hinder adoptions since studies have shown that adopters view cats that are more active for longer periods of time and more frequently compared to inactive cats, leading to an increased adoption rate (Fantuzzi et al. 2010).

In addition, stress and immunity are closely linked, with chronic stress contributing to immunosuppression, which can lead to the development of infectious diseases such as upper respiratory disease (Gaskel and Povey 1977). Stress can also lead to behavioral concerns such as inappropriate elimination. Accordingly, reducing stress within the shelter environment is crucial to maintaining feline well‐being, health, and adoptability.

16.3.1 Considerations for the Macroenvironment

Macroenvironmental factors include lighting, sound, odor, temperature and visual stimulation. Managing the area surrounding primary enclosures is just as important in reducing feline stress as is managing the enclosure itself (Stella et al. 2014).

The macroenvironment should allow for natural light. Light and darkness should be provided to support the natural (circadian) rhythms of wakefulness and sleep (Newbury et al. 2010). Views outside of housing areas, toward outdoor views or neutral indoor spaces are recommended. The use of LED lighting is recommended over fluorescent lighting as LEDs do not emit bothersome flickering or buzzing noises that cats can hear but humans may not. LEDs also provide softer lighting, which mimics natural lighting that is better in line with how cats see (Pollard and Shoults 2018a, 2018b).

Cats have a much broader hearing range than humans, meaning they are more sensitive to noise, particularly when they cannot move away from loud noises. Exposure to noise within the macroenvironment should be minimized, including the barking of dogs (McCobb et al. 2005; Stella et al. 2014), loud conversations, music and slamming of cage doors. Housing areas should aim to minimize noise levels to less than 60 dB, a quiet conversational level (Stella and Buffington 2016). Design housing wards with highly absorptive ceiling materials to reduce reverberant noise (Pollard and Shoults 2018a).

Cats depend on olfactory cues more than humans, so they are also more sensitive to aversive odors. Minimize exposure to odors including strong disinfectants, unfamiliar animals, cigarette smoke and alcohol‐based hand sanitizers (Stella and Buffington 2016; Stella and Croney 2016). Try to maintain familiar scents within the environment when possible, such as familiar bedding containing the scent of the cat itself or its former home (Ellis et al. 2013).

Cats prefer a warmer ambient temperature than many other species, so maintain housing areas at 15.5–26.5° C (60–80° F) for temperature and 30–70% for humidity (Newbury et al. 2010; Stella and Buffington 2016). Higher humidity (e.g., 70%) has been correlated with reduced respiratory disease in animals as the increased moisture helps maintain healthier respiratory passages that can more readily resist pathogens (Griffin 2012).

The macroenvironment also means that cage banks are raised and set at least 18 inches off the floor so cats have a “view” (Griffin 2013; McCobb et al. 2005; Wagner et al. 2018a). Elevated cages are less stressful than floor level cages, because cats can better survey their environment from an elevated position (McCobb et al. 2005). This also allows for cats to be both monitored more readily by staff and viewed more readily by adopters at eye level, which in turn can increase feline adoptions (Fantuzzi et al. 2010; Sinn 2016). Fill top cages before using bottom cages and, if needed, elevate cage banks with cage bases (Wagner et al. 2018a) (see Figure 16.1). Avoid triple‐stacking cages as this removes cats from the eye‐level of caretakers and adopters.

Views of other animals, including dogs and other cats, should be avoided. Cats grow fearful when seeing conspecifics and even cats that are acclimated to living with dogs will become frightened when seeing unfamiliar dogs (Rodan and Cannon 2016). Avoid facing housing units toward each other. If this is not possible, try to angle housing units so cats do not directly face one another and ensure there is more than 4 ft. between facing housing units to mitigate droplet transmission of infectious diseases (Gaskell and Povey 1977; Povey and Johnson 1970). Partial cage front coverings can provide an additional way for cats to retreat so they are not forced to see unfamiliar conspecifics.

16.3.2 Considerations for the Microenvironment

Microenvironmental factors include the quality and quantity of space; different functional areas for eliminating, eating, and resting; and size and types of elimination facilities as well as hiding, stretching, and perching opportunities. Traditional, single‐compartment cages that provide less than 8–11 ft² of floor space per cat cannot offer these distinct functional areas and limit the expression of species typical behaviors (Stella and Buffington 2016). These smaller cages need to be proactively avoided or adapted, such as through portalization to create double‐compartments and overall larger housing areas, to provide improved welfare and well‐being.

First and foremost, primary enclosures must be safe for the animal. The Association of Shelter Veterinarians’ Guidelines for Standards of Care in Animal Shelters states that a “primary enclosure must be structurally sound and maintained in safe, working condition to properly confine animals, prevent injury, keep other animals out, and enable the animals to remain dry and clean. There must not be any sharp edges, gaps or other defects that could cause an injury or trap a limb or other body part. Secure latches or other closing devices must be present. Cage floors should be non‐slip and solid. It is unacceptable for primary enclosures to have wire‐mesh bottoms or slatted floors” (Newbury et al. 2010).

Primary enclosures should be tall and wide enough to allow cats to move about without touching sides of the cage and to fully stretch and express other common behaviors. The enclosure space should also be sufficient so that there is a minimum of 2 ft. between food and litter (Newbury et al. 2010). Accordingly, 8–11 ft² is the minimum amount of floor space required for the healthy housing of cats and to help reduce behavioral and medical concerns, including upper respiratory disease (Newbury et al. 2010; Wagner et al. 2018a, 2018b). Specifically, cats housed in 11 ft² of floor space were found to be significantly less stressed than those with only 5.3 ft² of space (Kessler and Turner 1999b), while risk of upper respiratory disease was found to be significantly higher in shelters housing cats in cages with less than 8 ft² of floor space (Wagner et al. 2018b). This space allotment refers to unobstructed floor space and does not include that provided by perches or other elevated resting areas. Functional separation of food and litter spaces, as well as the ability to move around adequately and change locations, provides a sense of control over the environment, which is necessary for avoiding stress (McMillan 2002). The Freedoms cannot be met without sufficient housing space allotment.

In short, primary enclosures should be large enough to allow for full body length stretching as well as separation of resting and eating areas from elimination areas. Double‐compartment enclosures can facilitate this separation by allowing cats to rest and eat in an area away from their elimination area. In addition, during cleaning double‐compartments allow for minimized animal handling and therefore less stress. This also leads to reduced likelihood of fomite transmission and increased safety as cats can be secured on one side of the compartment while cleaning occurs on the other side. Double‐compartment enclosures, therefore, uphold the tenets expressed in the Freedoms and Pillars.

Single‐compartment housing can be retrofitted with a portal to become double‐compartmentalized (see Figures 16.2 and 16.3). One common scenario seen is the retrofitting of two side‐to‐side, 2‐ft. wide, single stainless‐steel cages with a portal to create a double‐compartment configuration, which provides 8 ft² of floor space per cat. This modification is an improvement over singled‐compartment caging, but shelters purchasing new primary enclosures or entirely replacing older enclosures should consider going beyond this minimum requirement to allow for greater movement and options for cats by providing a minimum of 11 ft² of caging floor space per cat. In addition, primary enclosures with multiple portals can allow for additional cage units to be opened up during times of low shelter population, affording cats even more space (Pollard and Shoults 2018a; Wagner et al. 2018a).

New enclosures that are compartmentalized ideally should be configured of two equally sized compartments, as opposed to one large living compartment and one smaller litterbox compartment. In unequally sized double‐compartment units, fearful cats may seek more secure spaces and choose to rest in their litterboxes within the smaller compartment (Lewis 2017). Instead, the focus should be on providing large, equally sized, enriched spaces on both sides. If this is not possible, the living compartment should be at least 30–36 inches wide and the litterbox compartment should be at least 15 inches wide (Wagner et al. 2018a). Ensure that litterbox compartments do not have shelving that would restrict normal posturing when eliminating. Larger individual units, often manufactured with removable partitions, that meet minimum floor space requirements are alternatives to double‐compartment units but are less preferable as they do not allow for distinct separation between resting and elimination spaces.

Walk‐in housing that provides adequate space is an alternative to traditional caged housing and has the additional benefit of allowing adopters and caretakers to enter the enclosure and gently interact with cats more readily. If renovating a facility and housing capacity allows for it, dog runs can be converted into walk‐in cat housing (see Figure 16.4), while new facilities can create customized walk‐in cat living spaces (UC Davis Koret Shelter Medicine Program 2015) (see Figure 16.5).

Vertical space within primary enclosures, although not included in the minimum floor space requirement, is critical in allowing cats to express normal behaviors. A minimum of 30 inches of vertical height will allow for natural movement and increases the overall functional space and environmental complexity of an enclosure (Lewis 2017), encouraging exploratory behaviors such as climbing and jumping as well as providing space for elevated resting areas that offer a greater sense of security (Rochlitz 2000).

All cats, regardless of their demeanor and where they are housed within the shelter (adoption, isolation, or hold area), must have an opportunity to hide within their enclosure (Newbury et al. 2010). Hiding is a normal, adaptive behavior that reduces stress when cats are exposed to threats or unfamiliar and unpredictable environments (Arhant et al. 2015; Carlstead 1993; Gourkow and Fraser 2006; Kry and Casey 2007; McCune 1994; Rehnberg et al. 2015; Stella et al. 2014, 2017; van der Leij et al. 2019; Vinke et al. 2014). Studies show that hiding places are used more by cats with increased stress, indicated by behavioral stress scores (Ottway and Hawkins 2003; Rehnberg et al. 2015; Stella et al. 2014), and that hiding places help reduce stress as indicated by lower behavioral stress scores (Kry and Casey 2007; Vinke et al. 2014). Studies also show that hiding places can increase the behavioral repertoire of confined cats. The sense of security offered by hiding places can at some points increase exploratory behaviors in a cat, while at other points increase resting behavior. In both instances, the provision of hiding places indicates that a cat is more comfortable within its environment (de Oliveira et al. 2015; Kry and Casey 2007). However, attentive recognition of whether a cat is inactive due to comfort or is inactive due to stress is critical to maintaining welfare.

The inability to hide increases stress as it precludes the ability to control aversive stimuli. Persistently stressed cats may not adapt to a new environment and, accordingly, will not display as much active, exploratory play behavior, which may affect their adoption likelihood (Carlstead 1993; Griffin and Hume 2006). Visual concealment can be offered through the provision of hiding places within the primary enclosure or by partially covering the front of an enclosure. Offering the choice to hide is equally important, so visual concealment techniques should allow cats the choice to hide if they need to and, conversely, allow them to be exploratory and exposed if they would like to be. Examples of hiding places include cardboard boxes, cat carriers with their doors open, feral dens or beds with high sides. Hiding places should be placed in the back of the cage, turned to the side so cats do not have to look out and, ideally, be enclosed on three sides to maximize the sense of physical protection. In cats that are comfortable in their new environment, hiding boxes can be oriented forward so cats can look out if they want to (Rodan and Cannon 2016) (see Figure 16.6). Line hiding places with soft bedding for additional comfort.

If the primary enclosure is not large enough to house a hiding box, then draping a towel over a shelf or an elevated bed (see Figure 16.7) or placing a partial covering on an enclosure’s front can also work (see Figure 16.8). Cats that are not given the opportunity to hide have been noted to turn cage furnishings upside down and shred newspaper within their cage at night or crouch behind their bed or litterbox in what seems to be an attempt to conceal themselves (Carlstead 1993; Gourkow and Fraser 2006; Kry and Casey 2007; Vinke et al. 2014). Cats may do this when they are struggling to cope with their environment or when they are sick (Stella and Buffington 2016).

Concerns that hiding opportunities impede adoption rates are unfounded. Studies have shown no negative effect on length of stay or adoption rate when shelters provide cats with hide spots. In addition, no difference in time to adoption has been shown between cats with hiding places versus cats without hiding places (Gourkow and Fraser 2006; Kry and Casey 2007). Studies instead show that providing the option to hide leads to improved welfare and, accordingly, can help cats appear more relaxed and social. These cats are likely to be more affiliative and approach people. Conversely, cats without hiding places have decreased welfare with no adoption advantage.

Bedding not only serves as a source of comfort but as a source of familiarity. Thick soft bedding should be provided to ensure cats achieve extended periods of normal deep sleep (Griffin 2012). Bedding, which can become a source of a familiar scent, should be laundered only when soiled and/or if a primary enclosure is being prepared for a new cat. Bedding should not cover the entirety of the floor of an enclosure as cats should have the choice to lay on bedding or on a different surface as desired.

Scratching allows cats to exhibit a normal behavior used to mark territory with visual and olfactory signaling. A variety of scratching substrates that can be discarded should be provided as preferred substrates vary between cats. Examples include disposable cardboard scratchers or carpet squares. In addition, while most cats prefer vertical scratch pads, some cats will use horizontal ones, so both types should be provided. Many cats scratch more after resting or sleeping so scratching pads can be strategically placed around resting areas (Rochlitz 2005).

Even color palettes matter when it comes to feline housing. Because cats can see in the ultraviolet B spectrum, avoid manmade materials that appear to fluoresce or reflect such as bright white plastics, which can be visually jarring to cats. Select matte finishes when possible. Cats have superior night vision but cannot see the red end of the human visible spectrum. Reds and oranges appear dull grey and shadowy to cats, making it harder to differentiate surfaces. Accordingly, choose light colors, such as blues, greens, and violets, within and surrounding enclosures so cats can better comprehend the environment around them in low‐light situations (Pollard and Shoults 2018b).

Every cat should have a high point to perch on (Newbury et al. 2010). Elevation and the ability to perch are stress reducers as they offer a sense of security from a vantage point and an area to retreat if needed (Ellis et al. 2013; Rochlitz 2007). Cats prefer elevated spaces more than floor areas (Rochlitz et al. 1998). Perches also maximize the functional space of an enclosure and should be both wide and long enough for a cat to fully stretch out (Ellis et al. 2013). At a minimum, perching shelves should be 12 inches wide and raised 13–14 inches off the cage floor to accommodate hiding boxes under them (Wagner et al. 2018a). Ensure ease of access to elevated areas for cats with reduced mobility due to old age, injury, or disease by providing steps and non‐slip surfaces. Avoid built‐in shelves as they can be hard to clean and limit the configuration of housing (Wagner et al. 2018a). Elevated walkways and hammocks also work well to provide elevation.