Animal Behavior for Shelter Veterinarians and Staff. Группа авторов
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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. In addition, 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 (see Figure 4.1). While some behavioral changes can be associated with organic diseases, such as space‐occupying masses in the central nervous system or the changes that occur as a result of infection and/or inflammation, other behaviors can result from 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.
Using a medical model approach to problem behaviors can improve communications between caregivers, shelter staff, and the rest of the health care team. This approach broadly categorizes behavior problems using terminology similar to that used in human mental health. However, these categories are purely descriptive and often attempt to assign a motivation to the unwanted behavior. This terminology does not necessarily 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). Having a thorough understanding of normal species‐typical behaviors for the animal in question is 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. See Chapters 12 and 18 for more information on training and behavior modification.
Figure 4.1 This diagram depicts how genetics, the environment, and medical conditions/disease processes all contribute to behavior. The relationship and interconnectedness of all of these components will be reflected in the overall health and welfare of the individual.
A variety of different disease processes can cause and/or contribute to the worsening of both maladaptive and malfunctional behaviors. Many individuals will simply differ in how readily they react to stimuli, the degree to which they respond, and how long they stay emotionally aroused. These differences often represent normal individual variations in temperament and are also affected by an individual’s experience during development.
4.3 Recognizing the Behavior of the Sick Animal
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 (see Box 4.1). Fever has the effect of assisting the animal to combat infectious disease by potentiating numerous immunologic responses (Hart 2010; Hart 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 febrile animals feel 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 can lead to a significant amount of water loss, especially critical to a febrile animal attempting to conserve water, energy, and body heat.
Box 4.1 General Behavioral Responses to Illness in Dogs and Cats
Reduced activity
Reduced appetite
Decreased water intake
Increased sleep
Decreased interest in social interaction
Decreased play behavior
Decreased grooming behavior
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.
An animal’s coat can provide important clues regarding its health status. 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 and thermoregulation, as well as effectively decreasing ectoparasite loads (Hart 2011). 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 normal self‐grooming behavior, it should serve as a warning sign that something is wrong.
4.3.1 Cats
Some dogs can be adept at hiding their illnesses, but cats are even better at it. This may be due to the cat’s unusual position of being both predator and prey, depending upon the environment. Anorexia is often the first sign noted by caretakers of sick cats. The fastidious nature of the cat contributes to the ability to mask signs of disease. For example, if cats have diarrhea, they are likely to clean themselves, removing all signs of the mess, until they become too ill to do so. The more sedentary and nocturnal nature of the cat may also cause caretakers to overlook inactivity due to illness until it becomes severe. Unkempt hair coat in a cat should be immediately noted and a possible cause investigated because the cat must be either ill, injured, or otherwise impaired in its movement in order for it to stop grooming itself.
A variety of different studies have suggested that monitoring sickness behaviors in the cat may be an excellent means of evaluating feline welfare and that cats’ behavior is a more reliable indicator of their level of stress than their physiological responses (Stella et al. 2013). One study demonstrated that the presence of unusual external events is enough to increase the risk of sickness behaviors in cats (Stella et al. 2011). When cats are exposed to multiple unpredictable stressors, including exposure to unfamiliar caretakers, an inconsistent husbandry schedule, and discontinuation of play time, socialization, food treats, and auditory enrichment, they demonstrate a higher incidence of sickness behaviors (Stella