Clinical Case
A 3-year-old female spayed Weimaraner is presented for behavioral consultation. Since she was a young puppy the dog has not handled separation. Prior to the owner’s leaving the dog whines, paces, hypersalivates, and follows them throughout the house. After the owners depart, the dog barks incessantly and has destroyed the wall near the doors and windows. Crate confinement has only worsened the problem and the dog has fractured several teeth in her attempts to escape the crate. In addition, the dog has begun to lick its right forearm constantly. The skin on its right forearm is thickened and ulcerated.
What motivates such reactions? Why do some fear responses worsen instead of improving with repeated exposures? How do compulsive disorders tie into these anxieties?
Problem Definition and Recognition
Fear is an emotional reaction to a perceived threat characterized by specific body language (Table 7-1) and involuntary physiologic responses, typically increasing in severity with the intensity of the threat. Phobia is a similar response except that it is a maximal intensity response on the basis of perception of the threat and is out of context with the level of threat and therefore is usually considered abnormal. Anxiety is a fearful response except that it occurs due to the perception that the threat is going to happen in the near future.
Compulsive behaviors (Table 7-2) are repetitive behaviors that occur out of context and typically are derived from normal maintenance behaviors such as grooming or locomotion. Typically, these compulsive behaviors develop when an animal is in conflict, trying to perform a behavior, yet is thwarted in its attempt to perform the behavior.
Pathogenesis
The fear response is an important lifesaving reaction, preparing the animal for flight or fight. Sensory input of an impending threat stimulates the locus ceruleus (LC) within the brain stem. Noradrenergic pathways lead from the LC to the cerebral cortex, spinal cord, and other centers within the limbic system. One of these structures in the limbic center, the amygdala, recalls memory of past fearful events. The amygdala in turn stimulates the autonomic nervous system to increase heart rate, respiratory rate, blood pressure, and the release of stress hormones. The amygdala is also important in fear conditioning, learning to pair a neutral stimulus to a fearful stimulus through classical (Pavlonian) conditioning.
TABLE 7-1. Fearful body language
| Sympathetic activation |
| Dilated eyes |
| Increased heart rate |
