for confirming the presence or absence of bacterial infections (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. Good antibiotic stewardship requires that we avoid treating cats presumptively with antibiotics since the likelihood of infection in young cats is small.
FIC has been shown to be the most common cause of signs of FLUTD in the cat (Lekcharoensuk et al. 2001; Gerber et al. 2005; Saevik et al. 2011). However, FIC is a diagnosis of exclusion. FIC describes recurring cystitis when no underlying cause for signs can be identified; a variety of different causative factors are suspected. Cats with FIC appear to have altered bladder permeability, 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 and Pacak 2001; Buffington et al. 2002), to be more sensitive to environmental stress, and to 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 to experience 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 to identify and reduce 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, 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 to decrease stress. Examples of these changes included avoidance of punishment, diet changes, techniques for increasing water consumption, changing to unscented clumping litter, improved litterbox management, provision of more 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. See Chapters 16 and 17 for more information on feline housing and enrichment.
4.6.4 Gastrointestinal Disorders
The nervous system of the gastrointestinal (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 have profound effects on the enteric nervous system (ENS). Severe life stressors have been associated with several GI tract conditions in humans (Bhatia and Tandon 2005), and the effects in animals are just now being explored. 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 and Tandon 2005). Many gastrointestinal conditions such as chronic diarrhea and vomiting may be closely associated with stress. However, when presented with an animal with GI signs, the possibility of internal parasites and infectious organisms must also be ruled out. Newer polymerase chain reaction (PCR) tests can be helpful in ruling out some of these conditions. It is important to always keep in mind that nothing precludes an animal from having GI distress from multiple etiologies; therefore, both infectious causes and stress may need to be addressed.
Disruptions in the microbiome have been shown to play a role in anxiety and depression in many species (Foster and Neufeld 2013). In addition, studies in laboratory animals have shown that when young developing animals do not have normal gut microbiomes, they develop an exaggerated stress response and a dysregulated HPA axis (Sudo et al. 2004). Minimal work has been done on the role of the gut microbiome on behavior in dogs, but some limited research suggests that dogs demonstrating aggressive behavior may have distinctly different populations of gut bacteria compared to dogs that do not show aggression (Kirchoff et al. 2019; Mondo et al. 2020). More research is needed to identify what constitutes a healthy gut microbiome and how to adjust an “unhealthy” gut before we can apply what we have learned to companion animal care. Once again, the impact of stress on normal development and general health is clear and reminds us that it must not be overlooked.
Behavioral signs that may be associated with gastrointestinal disease include polyphagia, hyperphagia, polydipsia, coprophagia, 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 also be associated with similar behaviors. 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 conditions such as gastroesophageal reflux (Frank et al. 2012).
4.6.4.1 Pica
Pica is the consumption of non‐nutritive items such as fabric, paper, and plastic. 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, ehrlichiosis, gastrointestinal disorders, neurologic damage, feline infectious peritonitis (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 and 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 associated with gastrointestinal disturbances and may be an adaptive mechanism used to cope with gastrointestinal upset (Takeda et al. 1993; Yamamoto et al. 2002). In a recent case report, a 5.5‐year‐old dog with a 4.5‐year history of pica (eating rocks) resolved when diagnosed and treated for mild hip dysplasia (Mills et al. 2020).
There is some indication in the literature that oriental cat breeds (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 and Dunham 2002; Bamberger and Houpt 2006). To date, the evidence for a genetic basis is purely correlative.
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 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 used behavior modification to diminish the occurrence of pica in a cat (Mongillo et al. 2012).
4.6.5 Dermatological Disease
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
