- Email: [email protected]
Successful treatment of abnormal feeding behavior in a cat
Journal of Veterinary Behavior (2012) 7, 390-393
CASE REPORT
Successful treatment of abnormal feeding behavior in a cat Paolo Mongilloa, Serena Adamellia,b, Marco Bernardinic, Elena Fraccarolib, Lieta Marinellia a
Dipartimento di Biomedicina Comparata e Alimentazione, Universita` degli Studi di Padova, Viale dell’Universita` 16, Legnaro, Padova, Italy; b C.S.C. S.R.L., Centro di Scienze Comportamentali del Cane, Universita` degli Studi di Padova, Via Padova, Padova, Italy; and c Dipartimento di Medicina Animale, Produzioni e Salute, Universita` degli Studi di Padova, Viale dell’Universita` 16, Legnaro, Padova, Italy. KEYWORDS: excessive appetite; feeding behavior; domestic cat; stress; behavioral treatment
Abstract An 8-month-old male cat was presented with a history of abnormal feeding behavior. Physical examination revealed a dull hair coat and slightly thin body condition. A detailed history and a behavioral examination revealed context-specific excessive appetite, pica, food-related aggressiveness, and excessive solicitation of interspecific interactions. Results of routine hematological and urine laboratory tests were normal, except for the presence of hyperglycemia. The presumptive diagnosis was of psychogenic abnormal feeding behavior. The treatment was aimed at reducing exposure to stressors and modifying the cat’s behavior through desensitization to food and counterconditioning to feeding. The diagnosis of a psychogenic problem was supported by the progression and the successful outcome of the proposed treatment. Given the lack of an exhaustive description of psychogenic abnormal feeding behavior in the scientific literature, the present case provides the first characterization of its clinical aspects and demonstrates the efficacy of treatment. Ó 2012 Elsevier Inc. All rights reserved.
Case presentation An 8-month-old neutered male Siamese cat was presented to the Animal Behavior Service of the Faculty of Veterinary Medicine, Universita` degli Studi di Padova. The main complaint, in the owners’ own words, was ‘‘the cat’s
Address for reprint requests and correspondence: Paolo Mongillo, DVM, PhD, Dipartimento di Biomedicina Comparata e Alimentazione, Universita` degli Studi di Padova, Viale dell’Universita` 16, 35020, Legnaro, Padova, Italy; Tel: 139-049-641862; Fax: 139-049-641174. E-mail: [email protected] 1558-7878/$ - see front matter Ó 2012 Elsevier Inc. All rights reserved. doi:10.1016/j.jveb.2012.02.005
obsession for food,’’ characterized by abnormal feeding behavior, including pica. The cat lived indoors with a 10-year-old, obese, spayed female cat and was fed 3 times a day with a commercial diet for neutered cats (Royal Canin Young Male S/O). On presentation, physical examination was unremarkable, except for a dull hair coat and a slightly thin body condition. A detailed neurological examination revealed no abnormalities. Because poor dietary management could have accounted for the cat’s condition, recommendations were made to switch to a kitten diet and to increase the frequency of
Mongillo et al
Abnormal feeding behavior in a cat
meals to 5 per day. Although an ad libitum feeding schedule would have been preferable (Manteca Vilanova, 2003), this option was impractical because of the presence of the obese cat. Fifteen days later, an improvement was seen in the cat’s hair coat and body condition, but no change was reported for the cat’s behavior toward food, ruling out insufficient caloric intake as a direct cause of the abnormal feeding pattern.
Behavioral history and evaluation A detailed history was taken to characterize the type, onset, and progression of behavioral signs. The cat had been adopted at the age of 8 weeks by the current owners, and the old, obese, spayed female cat was already present at the time of its adoption. The owners reported that, ever since the adoption, the cat would fling itself at the food bowl and voraciously eat its as well as the female cat’s food. The behavior worsened, and the cat began to steal food from the table and attempt to take food as the owners were bringing to their mouths to eat it. Later on, the cat started to cling to the food can whenever its meal was being prepared (Figure and Video S1), and to display aggressive behavior (hissing and growling) toward approaching humans or cats while eating. The owners tried to solve the undesirable situation by administering physical punishment (spraying with a squirt gun, smacking the cat with a newspaper) or coercively taking the cat away from the food. The cat also exhibited pica, preferring plastic objects of different colors and shapes. In some circumstances, despite the presence of food, the cat did not show abnormal behavior (e.g., when the owners were having breakfast in their bedroom or when the cat was fed dry food). During the history taking, the cat was let free in the examination room, where he expressed a normal
391 exploratory behavior. The cat was sociable toward people and insistently solicited attention with its forepaws from both the owner and the veterinarian. He also sought the owners’ physical contact, jumping on shoulders and laps and ‘‘kneading.’’ When exposed to food, the cat exhibited an abnormal feeding behavior in both its appetitive and consummatory phases: it rushed for the food can, clinging to it with its forepaws, voraciously consumed the whole ration, and looked for more food when done. When presented with a toy (a stick with feathers on one end), the cat exhibited abnormal predatory behavior, grasping the toy directly with the mouth and hissing. He also ingested the feathers.
Differential diagnosis On the basis of the physical examination and history, we considered as part of the differential diagnosis the conditions characterized by excessive appetite, namely, neurogenic, psychogenic, or endocrine dysfunction related polyphagic syndromes (Behrend, 2000). In fact, polyphagic syndromes may be characterized by excessive appetite or eating (MedlinePlus Medical Dictionary, 2012). In the case presented here, ingestion of excessive food (eating the female cat’s meals) as well as an abnormal appetite, as indicated by the cat’s behavior, was evident.
Laboratory examination Results of routine hematological and urine laboratory tests were within the reference range, except for the presence of hyperglycemia (268 mg/dL, reference interval [RI]: 86–116 mg/dL). Specific evaluations were conducted to rule out hyperadrenocorticism and hyperthyroidism, which can be associated with both hyperglycemia and increased appetite. Both urine cortisol/creatinine ratio (0.73, RI: 0.20–2.30) and free thyroxin serum levels (12.6 pmol/L, RI: 7.8– 12.8 pmol/L) were within the reference range.
Diagnosis
Figure Presenting signs. A video still showing the cat climbing onto the owner to reach the food can with the forepaws. The still was extracted from a video made by the owner on our request before the first examination.
Results of the laboratory diagnostic tests allowed us to exclude endocrine dysfunction, reducing the list of differential diagnosis to neurogenic polyphagia, a disruption of the hypothalamic nuclei that regulate food intake, and psychogenic abnormal feeding behavior. The latter was considered more likely, as the behavioral signs were context dependent rather than generalized, as one would expect in a neurological disorder. Moreover, the cat’s behavior during the examination strengthened the suspicion of the psychogenic origin of the cat’s abnormal behavior and hyperglycemia. Therefore, further diagnostics, which could have definitely ruled out a neurological disorder,
392
Journal of Veterinary Behavior, Vol 7, No 6, November/December 2012
were deferred until after attempting treatment for psychogenic abnormal feeding behavior.
when present at the owners’ meals. Moreover, abnormal social behaviors toward both the owners and the other cat were no longer exhibited.
Treatment and follow-up A therapeutic protocol was planned, aimed at reducing the exposure to potentially stressful conditions (such as a hypostimulating environment, unpredictable and aversive social interactions, and an inability to satisfy food- or social-related drives) and, subsequently, at modifying the cat’s behavior in response to food. For the first aim, the owners were asked to (1) provide appropriate environmental enrichment and satisfy exploratory and play needs, without eliciting either aggressive behavior or pica in the cat, (2) schedule a daily routine for frequent, short, pleasant interactions, while ignoring the cat’s requests for attention at other times, (3) reward calm behaviors and avoid any form of punishment, and (4) prevent exposure of the cat to food, except at the time of its meals, which should thereafter consist of dry food only. Fifteen days after starting the treatment, improvement was reported in the behavior of the cat, who appeared more relaxed and sought less attention from the owners. Because the sight of food was prevented, no abnormal feeding behavior was reported in this period. Based on this progress, desensitization to food associated with counterconditioning was initiated. Desensitization involves a gradual exposure to the stimulus that normally evokes the undesired behavior. Thus, the cat was initially allowed to be present only at the owners’ breakfasts, a situation in which it had shown some degree of self-control. As the treatment progressed, the cat was allowed to attend the owners’ main meals, which gradually included more appealing food (e.g., steamed rice at first, meat or fish eventually). Counterconditioning is the process whereby an animal is trained to perform a behavior that is incompatible with the undesired behavior, when presented with the precipitating stimulus. In this case, the owners were instructed to teach the cat a simple behavior to perform on command (‘‘sit!’’) whenever food was presented, and to reward the cat if it responded appropriately. After 1 month, the cat’s requests for the owners’ attention increased in frequency and included vocalizations and jumping onto the owners’ shoulder when they were in a crouched position. Moreover, the cat repeatedly showed aggressive behavior toward the female cat, while waiting for its meal to be prepared. The owners were asked to separate the 2 cats in this context and to continue the progressive behavioral modification protocol. During subsequent monthly follow-ups, the owner reported a consistent improvement in the cat’s feeding and aggressive behaviors. At the time of the last examination, 5 months after the initial presentation, the cat did not show any abnormal behavior at the sight of food (Video S2), and it remained relaxed
Discussion An abnormal increase in appetite, with alterations in feeding behavior, may be found in the course of several pathological conditions, including endocrine, infectious, gastrointestinal, neurological, and psychogenic disorders, and conditions in which energetic demand is not met by diet. Although the differential diagnosis would require an initial assessment of the fluctuation in the cat’s body weight (Behrend, 2000), this could not be performed in our patient, since the cat was still growing. Most conditions could be ruled out by the absence of other common accompanying signs and the lack of alterations in hematological and urinary parameters. The concurrent presence of excessive appetite and hyperglycemia could indicate hyperthyroidism or hyperadrenocorticism. Hyperthyroidism was unlikely, given the cat’s young age (Gunn-Moore, 2005), and the condition was definitely excluded on the basis of free thyroxine levels (Peterson, 2006). Hyperadrenocorticism, which can be characterized by a dull hair coat and very vague clinical symptoms, was ruled out by evaluating the urinary cortisol/creatinine ratio (Gunn-Moore, 2005). In the absence of glycosuria and other clinical signs, hyperglycemia was most likely a transient consequence of stress (Opitz, 1990), possibly associated with clinical procedures. Psychogenic alterations in the cat’s feeding behavior have not been specifically discussed in the scientific literature and are only mentioned in veterinary internal medicine textbooks (Behrend, 2000). In the behavioral medicine literature, altered feeding patterns are often reported among compulsive disorders (CDs)/obsessive–compulsive disorders (OCDs) (Hewson and Luescher, 1996; Overall and Dunham, 2002; Askew, 2003). The present case lacked 2 necessary features of CDs, namely, the expression of a behavior out of context (Hewson and Luescher, 1996) and the interference with normal daily activities (Overall and Dunham, 2002). Moreover, improvements are seldom seen in CDs/OCDs without a pharmacological intervention (Luescher, 2009). In the present case, it was impossible to ascertain the primary cause of the abnormal behavior, as this behavior was present at adoption and we could not obtain information on the preadoption period of the cat’s life. In contrast, it is well known that early experiences are crucial for the development of appropriate adult behaviors. Studies on rodent models demonstrate that even mildly stressful experiences in early life may result in the acquisition of abnormal feeding patterns (Jahng, 2011). After adoption, both inadequate environmental stimuli and the lack of control and predictability about social interactions represented likely causes of stress (Carlstead et al., 1993), which could have exacerbated the
Mongillo et al
Abnormal feeding behavior in a cat
cat’s maladaptive response. It should be noted that feeding is a self-rewarding behavior, which holds a stress-relieving value per se (Urlich-Lai et al., 2011). Challenges deriving from physical and social environment, including rehoming and competition with the other cat, may also have triggered pica, an abnormal behavior for which Siamese cats appear to be predisposed (Bradshaw et al., 1997). Regardless of what caused the increase in appetite in the first place, a reward mechanism is likely to have contributed to maintaining or exacerbating the cat’s abnormal behavior in response to food. The successful outcome of the treatment supported the presumptive diagnosis of a psychogenic disease. Moreover, the behavioral escalation that was seen during the treatment is consistent with extinction (i.e., the termination of the reinforcement contingency that maintains an acquired response; Pearce, 2008), supporting a learning component in the expression of the abnormal feeding behavior. To the best of our knowledge, this case is the first report of psychogenic abnormal feeding behavior in a cat. Although the condition is mentioned in veterinary literature, there is virtually no knowledge on its clinical presentation, pathogenesis, and treatment options. The present case is relevant, as it not only provides the first characterization of this condition, but also shows the efficacy of treatment.
Supplementary data Supplementary data related to this article can be found online at doi:10.1016/j.jveb.2012.02.005.
393
References Askew, H.R., 2003. Treatment of Behavior Problems in Dogs and Cats, 2nd Ed. Blackwell Publishing, Berlin-Vienna, pp. 365-377. Behrend, E.N., 2000. Polyphagia. In: Ettinger, S.J., Feldman, E.C. (Eds.), Textbook of Veterinary Internal Medicine. Diseases of the Dog and Cat, 5th Ed. WB Saunders, Philadelphia, PA, pp. 104-107. Bradshaw, J.W.S., Neville, P.F., Sawyer, D., 1997. Factors affecting pica in the domestic cat. Appl. Anim. Behav. Sci. 52, 373-379. Carlstead, K., Brown, J.L., Strawn, W., 1993. Behavioral and physiological correlates of stress in laboratory cats. Appl. Anim. Behav. Sci. 32, 143-158. Gunn-Moore, D., 2005. Feline endocrinopathies. Vet. Clin. North Am. Small Anim. Pract. 35, 171-210. Hewson, C.J., Luescher, U.A., 1996. Compulsive disorders in dogs. In: Voith, V.L., Borchelet, P.L. (Eds.), Readings in Companion Animal Behavior. Veterinary Learning Systems, Trenton, NJ, pp. 153-158. Jahng, J.W., 2011. An animal model of eating disorders associated with stressful experience in early life. Horm. Behav. 59, 213-220. Luescher, A.U., 2009. Repetitive and compulsive behavior in dogs and cats. In: Horwitz, D., Mills, D. (Eds.), BSAVA Manual of Canine and Feline Behavioural Medicine, 2nd Ed. British Small Animal Veterinary Association, Gloucester, UK, pp. 229-236. Manteca Vilanova, X., 2003. Etologı´a Clı´nica Veterinaria del Perro y del Gato, 2nd Ed. Multime´dicas S.A., Barcelona, Spain, pp. 89-119. MedlinePlus medical dictionary, 2012. Available at: http://www.merriamwebster.com/medlineplus/polyphagia. Opitz, M., 1990. Stress hyperglycemia in cats. Berl. Munch. Tierarztl. Wochenschr. 103, 151-158. Overall, K.L., Dunham, A.E., 2002. Clinical features and outcome in dogs and cats with obsessive-compulsive disorders: 126 cases (1989-2000). J. Am. Vet. Med. Assoc. 221, 1445-1452. Pearce, J.M., 2008. Animal Learning and Cognition: An Introduction, 3rd Ed. Psychology Press, New York, NY. Peterson, M.E., 2006. Diagnostic tests for hyperthyroidism in cats. Clin. Tech. Small Anim. Pract. 21, 2-9. Ulrich-Lai, Y.M., Ostrander, M.M., James, H., 2011. HPA axis dampening by limited sucrose intake: reward frequency vs. caloric consumption. Physiol. Behav. 103, 104-110.
CASE REPORT
Successful treatment of abnormal feeding behavior in a cat Paolo Mongilloa, Serena Adamellia,b, Marco Bernardinic, Elena Fraccarolib, Lieta Marinellia a
Dipartimento di Biomedicina Comparata e Alimentazione, Universita` degli Studi di Padova, Viale dell’Universita` 16, Legnaro, Padova, Italy; b C.S.C. S.R.L., Centro di Scienze Comportamentali del Cane, Universita` degli Studi di Padova, Via Padova, Padova, Italy; and c Dipartimento di Medicina Animale, Produzioni e Salute, Universita` degli Studi di Padova, Viale dell’Universita` 16, Legnaro, Padova, Italy. KEYWORDS: excessive appetite; feeding behavior; domestic cat; stress; behavioral treatment
Abstract An 8-month-old male cat was presented with a history of abnormal feeding behavior. Physical examination revealed a dull hair coat and slightly thin body condition. A detailed history and a behavioral examination revealed context-specific excessive appetite, pica, food-related aggressiveness, and excessive solicitation of interspecific interactions. Results of routine hematological and urine laboratory tests were normal, except for the presence of hyperglycemia. The presumptive diagnosis was of psychogenic abnormal feeding behavior. The treatment was aimed at reducing exposure to stressors and modifying the cat’s behavior through desensitization to food and counterconditioning to feeding. The diagnosis of a psychogenic problem was supported by the progression and the successful outcome of the proposed treatment. Given the lack of an exhaustive description of psychogenic abnormal feeding behavior in the scientific literature, the present case provides the first characterization of its clinical aspects and demonstrates the efficacy of treatment. Ó 2012 Elsevier Inc. All rights reserved.
Case presentation An 8-month-old neutered male Siamese cat was presented to the Animal Behavior Service of the Faculty of Veterinary Medicine, Universita` degli Studi di Padova. The main complaint, in the owners’ own words, was ‘‘the cat’s
Address for reprint requests and correspondence: Paolo Mongillo, DVM, PhD, Dipartimento di Biomedicina Comparata e Alimentazione, Universita` degli Studi di Padova, Viale dell’Universita` 16, 35020, Legnaro, Padova, Italy; Tel: 139-049-641862; Fax: 139-049-641174. E-mail: [email protected] 1558-7878/$ - see front matter Ó 2012 Elsevier Inc. All rights reserved. doi:10.1016/j.jveb.2012.02.005
obsession for food,’’ characterized by abnormal feeding behavior, including pica. The cat lived indoors with a 10-year-old, obese, spayed female cat and was fed 3 times a day with a commercial diet for neutered cats (Royal Canin Young Male S/O). On presentation, physical examination was unremarkable, except for a dull hair coat and a slightly thin body condition. A detailed neurological examination revealed no abnormalities. Because poor dietary management could have accounted for the cat’s condition, recommendations were made to switch to a kitten diet and to increase the frequency of
Mongillo et al
Abnormal feeding behavior in a cat
meals to 5 per day. Although an ad libitum feeding schedule would have been preferable (Manteca Vilanova, 2003), this option was impractical because of the presence of the obese cat. Fifteen days later, an improvement was seen in the cat’s hair coat and body condition, but no change was reported for the cat’s behavior toward food, ruling out insufficient caloric intake as a direct cause of the abnormal feeding pattern.
Behavioral history and evaluation A detailed history was taken to characterize the type, onset, and progression of behavioral signs. The cat had been adopted at the age of 8 weeks by the current owners, and the old, obese, spayed female cat was already present at the time of its adoption. The owners reported that, ever since the adoption, the cat would fling itself at the food bowl and voraciously eat its as well as the female cat’s food. The behavior worsened, and the cat began to steal food from the table and attempt to take food as the owners were bringing to their mouths to eat it. Later on, the cat started to cling to the food can whenever its meal was being prepared (Figure and Video S1), and to display aggressive behavior (hissing and growling) toward approaching humans or cats while eating. The owners tried to solve the undesirable situation by administering physical punishment (spraying with a squirt gun, smacking the cat with a newspaper) or coercively taking the cat away from the food. The cat also exhibited pica, preferring plastic objects of different colors and shapes. In some circumstances, despite the presence of food, the cat did not show abnormal behavior (e.g., when the owners were having breakfast in their bedroom or when the cat was fed dry food). During the history taking, the cat was let free in the examination room, where he expressed a normal
391 exploratory behavior. The cat was sociable toward people and insistently solicited attention with its forepaws from both the owner and the veterinarian. He also sought the owners’ physical contact, jumping on shoulders and laps and ‘‘kneading.’’ When exposed to food, the cat exhibited an abnormal feeding behavior in both its appetitive and consummatory phases: it rushed for the food can, clinging to it with its forepaws, voraciously consumed the whole ration, and looked for more food when done. When presented with a toy (a stick with feathers on one end), the cat exhibited abnormal predatory behavior, grasping the toy directly with the mouth and hissing. He also ingested the feathers.
Differential diagnosis On the basis of the physical examination and history, we considered as part of the differential diagnosis the conditions characterized by excessive appetite, namely, neurogenic, psychogenic, or endocrine dysfunction related polyphagic syndromes (Behrend, 2000). In fact, polyphagic syndromes may be characterized by excessive appetite or eating (MedlinePlus Medical Dictionary, 2012). In the case presented here, ingestion of excessive food (eating the female cat’s meals) as well as an abnormal appetite, as indicated by the cat’s behavior, was evident.
Laboratory examination Results of routine hematological and urine laboratory tests were within the reference range, except for the presence of hyperglycemia (268 mg/dL, reference interval [RI]: 86–116 mg/dL). Specific evaluations were conducted to rule out hyperadrenocorticism and hyperthyroidism, which can be associated with both hyperglycemia and increased appetite. Both urine cortisol/creatinine ratio (0.73, RI: 0.20–2.30) and free thyroxin serum levels (12.6 pmol/L, RI: 7.8– 12.8 pmol/L) were within the reference range.
Diagnosis
Figure Presenting signs. A video still showing the cat climbing onto the owner to reach the food can with the forepaws. The still was extracted from a video made by the owner on our request before the first examination.
Results of the laboratory diagnostic tests allowed us to exclude endocrine dysfunction, reducing the list of differential diagnosis to neurogenic polyphagia, a disruption of the hypothalamic nuclei that regulate food intake, and psychogenic abnormal feeding behavior. The latter was considered more likely, as the behavioral signs were context dependent rather than generalized, as one would expect in a neurological disorder. Moreover, the cat’s behavior during the examination strengthened the suspicion of the psychogenic origin of the cat’s abnormal behavior and hyperglycemia. Therefore, further diagnostics, which could have definitely ruled out a neurological disorder,
392
Journal of Veterinary Behavior, Vol 7, No 6, November/December 2012
were deferred until after attempting treatment for psychogenic abnormal feeding behavior.
when present at the owners’ meals. Moreover, abnormal social behaviors toward both the owners and the other cat were no longer exhibited.
Treatment and follow-up A therapeutic protocol was planned, aimed at reducing the exposure to potentially stressful conditions (such as a hypostimulating environment, unpredictable and aversive social interactions, and an inability to satisfy food- or social-related drives) and, subsequently, at modifying the cat’s behavior in response to food. For the first aim, the owners were asked to (1) provide appropriate environmental enrichment and satisfy exploratory and play needs, without eliciting either aggressive behavior or pica in the cat, (2) schedule a daily routine for frequent, short, pleasant interactions, while ignoring the cat’s requests for attention at other times, (3) reward calm behaviors and avoid any form of punishment, and (4) prevent exposure of the cat to food, except at the time of its meals, which should thereafter consist of dry food only. Fifteen days after starting the treatment, improvement was reported in the behavior of the cat, who appeared more relaxed and sought less attention from the owners. Because the sight of food was prevented, no abnormal feeding behavior was reported in this period. Based on this progress, desensitization to food associated with counterconditioning was initiated. Desensitization involves a gradual exposure to the stimulus that normally evokes the undesired behavior. Thus, the cat was initially allowed to be present only at the owners’ breakfasts, a situation in which it had shown some degree of self-control. As the treatment progressed, the cat was allowed to attend the owners’ main meals, which gradually included more appealing food (e.g., steamed rice at first, meat or fish eventually). Counterconditioning is the process whereby an animal is trained to perform a behavior that is incompatible with the undesired behavior, when presented with the precipitating stimulus. In this case, the owners were instructed to teach the cat a simple behavior to perform on command (‘‘sit!’’) whenever food was presented, and to reward the cat if it responded appropriately. After 1 month, the cat’s requests for the owners’ attention increased in frequency and included vocalizations and jumping onto the owners’ shoulder when they were in a crouched position. Moreover, the cat repeatedly showed aggressive behavior toward the female cat, while waiting for its meal to be prepared. The owners were asked to separate the 2 cats in this context and to continue the progressive behavioral modification protocol. During subsequent monthly follow-ups, the owner reported a consistent improvement in the cat’s feeding and aggressive behaviors. At the time of the last examination, 5 months after the initial presentation, the cat did not show any abnormal behavior at the sight of food (Video S2), and it remained relaxed
Discussion An abnormal increase in appetite, with alterations in feeding behavior, may be found in the course of several pathological conditions, including endocrine, infectious, gastrointestinal, neurological, and psychogenic disorders, and conditions in which energetic demand is not met by diet. Although the differential diagnosis would require an initial assessment of the fluctuation in the cat’s body weight (Behrend, 2000), this could not be performed in our patient, since the cat was still growing. Most conditions could be ruled out by the absence of other common accompanying signs and the lack of alterations in hematological and urinary parameters. The concurrent presence of excessive appetite and hyperglycemia could indicate hyperthyroidism or hyperadrenocorticism. Hyperthyroidism was unlikely, given the cat’s young age (Gunn-Moore, 2005), and the condition was definitely excluded on the basis of free thyroxine levels (Peterson, 2006). Hyperadrenocorticism, which can be characterized by a dull hair coat and very vague clinical symptoms, was ruled out by evaluating the urinary cortisol/creatinine ratio (Gunn-Moore, 2005). In the absence of glycosuria and other clinical signs, hyperglycemia was most likely a transient consequence of stress (Opitz, 1990), possibly associated with clinical procedures. Psychogenic alterations in the cat’s feeding behavior have not been specifically discussed in the scientific literature and are only mentioned in veterinary internal medicine textbooks (Behrend, 2000). In the behavioral medicine literature, altered feeding patterns are often reported among compulsive disorders (CDs)/obsessive–compulsive disorders (OCDs) (Hewson and Luescher, 1996; Overall and Dunham, 2002; Askew, 2003). The present case lacked 2 necessary features of CDs, namely, the expression of a behavior out of context (Hewson and Luescher, 1996) and the interference with normal daily activities (Overall and Dunham, 2002). Moreover, improvements are seldom seen in CDs/OCDs without a pharmacological intervention (Luescher, 2009). In the present case, it was impossible to ascertain the primary cause of the abnormal behavior, as this behavior was present at adoption and we could not obtain information on the preadoption period of the cat’s life. In contrast, it is well known that early experiences are crucial for the development of appropriate adult behaviors. Studies on rodent models demonstrate that even mildly stressful experiences in early life may result in the acquisition of abnormal feeding patterns (Jahng, 2011). After adoption, both inadequate environmental stimuli and the lack of control and predictability about social interactions represented likely causes of stress (Carlstead et al., 1993), which could have exacerbated the
Mongillo et al
Abnormal feeding behavior in a cat
cat’s maladaptive response. It should be noted that feeding is a self-rewarding behavior, which holds a stress-relieving value per se (Urlich-Lai et al., 2011). Challenges deriving from physical and social environment, including rehoming and competition with the other cat, may also have triggered pica, an abnormal behavior for which Siamese cats appear to be predisposed (Bradshaw et al., 1997). Regardless of what caused the increase in appetite in the first place, a reward mechanism is likely to have contributed to maintaining or exacerbating the cat’s abnormal behavior in response to food. The successful outcome of the treatment supported the presumptive diagnosis of a psychogenic disease. Moreover, the behavioral escalation that was seen during the treatment is consistent with extinction (i.e., the termination of the reinforcement contingency that maintains an acquired response; Pearce, 2008), supporting a learning component in the expression of the abnormal feeding behavior. To the best of our knowledge, this case is the first report of psychogenic abnormal feeding behavior in a cat. Although the condition is mentioned in veterinary literature, there is virtually no knowledge on its clinical presentation, pathogenesis, and treatment options. The present case is relevant, as it not only provides the first characterization of this condition, but also shows the efficacy of treatment.
Supplementary data Supplementary data related to this article can be found online at doi:10.1016/j.jveb.2012.02.005.
393
References Askew, H.R., 2003. Treatment of Behavior Problems in Dogs and Cats, 2nd Ed. Blackwell Publishing, Berlin-Vienna, pp. 365-377. Behrend, E.N., 2000. Polyphagia. In: Ettinger, S.J., Feldman, E.C. (Eds.), Textbook of Veterinary Internal Medicine. Diseases of the Dog and Cat, 5th Ed. WB Saunders, Philadelphia, PA, pp. 104-107. Bradshaw, J.W.S., Neville, P.F., Sawyer, D., 1997. Factors affecting pica in the domestic cat. Appl. Anim. Behav. Sci. 52, 373-379. Carlstead, K., Brown, J.L., Strawn, W., 1993. Behavioral and physiological correlates of stress in laboratory cats. Appl. Anim. Behav. Sci. 32, 143-158. Gunn-Moore, D., 2005. Feline endocrinopathies. Vet. Clin. North Am. Small Anim. Pract. 35, 171-210. Hewson, C.J., Luescher, U.A., 1996. Compulsive disorders in dogs. In: Voith, V.L., Borchelet, P.L. (Eds.), Readings in Companion Animal Behavior. Veterinary Learning Systems, Trenton, NJ, pp. 153-158. Jahng, J.W., 2011. An animal model of eating disorders associated with stressful experience in early life. Horm. Behav. 59, 213-220. Luescher, A.U., 2009. Repetitive and compulsive behavior in dogs and cats. In: Horwitz, D., Mills, D. (Eds.), BSAVA Manual of Canine and Feline Behavioural Medicine, 2nd Ed. British Small Animal Veterinary Association, Gloucester, UK, pp. 229-236. Manteca Vilanova, X., 2003. Etologı´a Clı´nica Veterinaria del Perro y del Gato, 2nd Ed. Multime´dicas S.A., Barcelona, Spain, pp. 89-119. MedlinePlus medical dictionary, 2012. Available at: http://www.merriamwebster.com/medlineplus/polyphagia. Opitz, M., 1990. Stress hyperglycemia in cats. Berl. Munch. Tierarztl. Wochenschr. 103, 151-158. Overall, K.L., Dunham, A.E., 2002. Clinical features and outcome in dogs and cats with obsessive-compulsive disorders: 126 cases (1989-2000). J. Am. Vet. Med. Assoc. 221, 1445-1452. Pearce, J.M., 2008. Animal Learning and Cognition: An Introduction, 3rd Ed. Psychology Press, New York, NY. Peterson, M.E., 2006. Diagnostic tests for hyperthyroidism in cats. Clin. Tech. Small Anim. Pract. 21, 2-9. Ulrich-Lai, Y.M., Ostrander, M.M., James, H., 2011. HPA axis dampening by limited sucrose intake: reward frequency vs. caloric consumption. Physiol. Behav. 103, 104-110.