Table 4.1 Common Stressors and Behavioral Signs of Stress in Shelter Dogs and Cats (Jones and Josephs 2006; Horváth et al. 2008; Beerda et al. 1998, 1999; Carlstead et al. 1993; Kessler and Turner 1999b; Tanaka et al. 2012; Kessler and Turner 1997; Dinnage 2006).
| Common stressors | Behavioral signs of stress |
|---|---|
| Dogs | |
| Separation from familiar social figures Loud noises Restraint and unpredictable handling Confinement Elimination on unfamiliar surfaces and/or in living space Sounds and odors associated with the stress and aggressive behavior of other dogs Altered routines Immersion in novel environment, surrounded by novel stimuli | Trembling Crouching Oral behaviors (e.g., snout licking, swallowing, smacking) Yawning Restlessness Lowered body posture Increased autogrooming Paw lifting Vocalizing Repetitive behavior Coprophagy |
| Cats | |
| Unpredictable handling and husbandry routines Increased density of group‐housing Inability to hide | Decreased food intake and weight loss Less play and active exploratory behaviors More time awake and alert Attempting to hide Behavioral apathy Vocalization Escape behaviors Aggressive behavior Feigned sleep |
4.5 The Behavior of Pain
Recognizing the behavioral signs of pain in non‐verbal species is challenging. Because animals can’t tell us when they experience pain, it is critical to train shelter staff to recognize their non‐verbal signs if we are to ensure good welfare. A number of problem behaviors can occur in dogs and cats in response to pain. These can include irritability (increased sensitivity and reactivity to stimuli), aggressiveness, restlessness, excessive vocalization, changes in activity level, and an increase in anxiety‐related behaviors. In an animal that was previously behaviorally stable, 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 be familiar enough with an individual to determine what is normal or abnormal for that animal. To further complicate matters, physiologic responses to pain and stress can be similar, and because animals entering a shelter are likely to experience stress, this may make differentiating the two very difficult. In addition, it is normal for most animals to try to mask their pain, and they may be even more likely to do this when placed in a stressful situation.
The objective signs of medical problems that typically result in pain cannot always be identified with a physical exam, radiographs, laboratory work, and so forth. Therefore, it is generally accepted that behavioral rather than physiological signs are the most important parameters we should attend to when evaluating pain in animals (Epstein et al. 2015). We should also always keep in mind that if a procedure, injury, or illness causes pain in humans, then it would be wise to assume that it causes pain in dogs and cats as well.
Different animals will manifest pain differently, and there is no single behavior that can be considered pathognomonic for pain. Neither does the absence of certain behaviors always indicate the absence of pain. Many behaviors considered to be indicative of pain can also occur due to anxiety or fear in both dogs and cats. In addition, the presence of other diseases can change the appearance of pain behaviors. Several studies have found that subjective behavioral measures can be used successfully to identify pain in animals and subsequently evaluate the efficacy of treatment (Holton et al. 1998; Cloutier et al. 2005; Bennett and Morton 2009). However, more research is needed to refine and validate some of the current methods. Because some diagnostic capabilities may be limited in a shelter situation, 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. Failure to recognize pain is a significant welfare concern. Training shelter staff is a crucial task for shelter management to ensure that staff can reliably and consistently recognize even the most subtle signs of pain in animals. Table 4.2 provides a summary of behavioral signs of pain in dogs and cats.
4.5.1 Cats
Improving our ability to identify pain in cats is important for many reasons. Degenerative joint disease (DJD) is more common in cats than previously believed (Perry 2014). Although some cats will appear pain free and still have joint abnormalities visible on radiographs (Monteiro and Steagall 2019), several studies have shown that signs of pain and discomfort associated with DJD commonly occur prior to the appearance of radiographic signs (Hardie et al. 2002; Clarke and Bennett 2006). Overt lameness is much less common in cats than dogs (Clarke and Bennett 2006). In addition, while palpation may be effective at determining when and where dogs experience pain, cats often resist palpation under normal circumstances; therefore, response to palpation is unlikely to be diagnostic for pain or discomfort. Osteoarthritis is not the only cause of chronic pain in the cat; pain secondary to cancer and dental disease (e.g., feline orofacial pain syndrome [FOPS]) should also be of concern.
4.5.2 Neuropathic Pain
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 and 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, and the mechanisms underlying the syndrome are unclear. The relief of neuropathic pain is generally considered extremely challenging.
The possibility of phantom limb pain, where the patient perceives pain in a limb that is no longer present, should also be considered as a possible outcome of amputation (Shilo and Pascoe 2014). 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 animals, it will be even more incumbent upon the caretaker to be extremely observant for signs of pain in animals.
Table 4.2 Behavioral signs of pain in dogs and cats (Mills et al. 2020; Bacon et al. 2019; Godfrey 2005; Bennett and Morton 2009; Slingerland et al. 2011).
| Dogs | Cats |
|---|---|
| More common | General signs |
| Anorexia Avoidance behaviors Hiding Aggression Hunched body posture Whining or howling Decreased social interactions Changes in activity level Changes in temperament or mood Reluctance to move or change position when recumbent or Increased restlessness and frequent changes in position Tense facial muscles with ears pulled back from the face and a grimace May attempt to bite at or lick a painful area May rub painful areas against walls, doors, or other objects Increased heart rate, respiratory rate, and/or blood pressure | Avoidance or flight behavior Restlessness or agitation Hunched posture Squinting eyes Reluctance to move Vocalization (including purring) Gait changes Decreased appetite Changes in grooming behavior Tail flicking Changes in interactions with people Decreased tolerance to handling Aggression when certain body parts are manipulated Aggression when attempting to move or lift |
|
Less common
|