These behaviors may be compulsive disorders, which are described as repetitive, ritualistic behaviors that are performed in excess of what is required for normal function and that interfere with normal daily activities.1 Compulsive behaviors are often initially associated with conflict or frustration and are later displayed out of context in other situations of high arousal.2 They can occupy a large percentage of a dog's daily time and adversely affect quality of life.
Treatment for compulsive disorders has mostly centered on the use of serotonin reuptake inhibitors, such as clomipramine (a tricyclic antidepressant), as well as behavior modification strategies to interrupt and redirect the problem behavior to a more appropriate activity.
However, before you begin treatment, a thorough history and medical evaluation are essential. It is especially important to rule out any medical disorders that can be a primary or contributing cause of repetitive behaviors. For example, two recent studies have shown that in the case of oral repetitive behaviors, an underlying gastrointestinal (GI) problem may be present.
A POSSIBLE GI TIE
Two studies by a group of researchers at the University of Montréal Veterinary Teaching Hospital have investigated medical causes for excessive licking of surfaces and fly biting in dogs.3,4 This research suggests that at least some of these cases are related to medical issues causing nausea or discomfort, thus triggering the odd oral behaviors.
Excessive licking study
In a prospective clinical study by this group of researchers, 19 dogs that displayed excessive licking of surfaces were compared with a control group of 10 healthy dogs.3
Complete medical and behavioral histories were collected for all dogs, and they all underwent physical and neurologic examinations. Each dog then underwent a thorough diagnostic evaluation that included an abdominal ultrasonographic examination, an endoscopic examination, and biopsies of the stomach and proximal duodenum.
For those dogs that licked, the mean duration of the licking behavior was 32 months, and 16 of the 19 dogs licked daily. The medical evaluation revealed that 14 of the 19 licking dogs had GI abnormalities, which included lymphocytic-plasmacytic infiltration, chronic pancreatitis, and, in one dog, a gastric foreign body.
Treatment of only the underlying GI disorder resulted in significant improvement in a majority of dogs in the licking group. While no GI disorder was identified in five of the 19 dogs in the licking group, four of these five improved with use of a hypoallergenic diet plus antacid or antiemetic medication.
Fly biting study
The same group of researchers also published a prospective case series that evaluated seven dogs that were presented with a history of daily fly biting behavior.4 The authors defined fly biting as a syndrome in which a dog appears to be staring at something and suddenly snaps at it.
Each dog in this case series had complete medical and behavioral histories collected in addition to undergoing physical and neurologic examinations. All the dogs were filmed during the behavioral assessment and for two hours after a meal to evaluate characteristics of the fly biting behavior. A complete blood count, serum chemistry profile, and urinalysis were performed in all dogs, and if there was a history of GI signs, a complete GI evaluation was performed. The behavioral histories of these dogs revealed that the fly biting behavior had been present from six days to four years before the study and that the behavior occurrence ranged from once daily to once every hour.
The video analyses revealed that all dogs raised their heads and extended their necks before fly biting, which may suggest esophageal discomfort. All dogs in this case series were diagnosed with a GI abnormality, and one dog was also diagnosed with Chiari malformation (a mismatch in volume between the caudal brain structures and the caudal skull associated with herniation of the cerebellum through the foramen magnum5).
Six of the seven dogs responded to medical treatment alone, four with complete resolution of the fly biting behavior. No psychoactive medications were administered concurrently with treatment of the medical issues.
WHAT'S THE TAKE-HOME?
Both studies reveal that GI disease can cause the repetitive behaviors of excessive licking of surfaces or fly biting and that these behaviors were significantly reduced with appropriate medical therapy for the GI issues. Future studies evaluating medical disorders in dogs with repetitive behaviors such as spinning or tail-chasing would also be worthwhile.
However, the take-home message here is not that compulsive disorders with a primary behavioral etiology do not exist. Rather, the key is recognizing that not all compulsive behaviors are strictly behavioral. All dogs with oral repetitive behaviors should undergo a complete medical work-up to rule out GI disease before evaluation for behavioral disorders (see "Case example: Charlie, the snapping poodle" below).
If you are presented with a patient with a repetitive behavior, this questionnaire  can be provided to the owner, to be completed either before or at the time of the appointment. Instruct the owner to bring a video of the pet's behavior to the appointment if possible.
The medical evaluation should include a thorough physical and neurologic examination and assessment of a complete blood count, serum chemistry profile, and urinalysis to rule out metabolic, dermatologic, orthopedic, and neurologic abnormalities.
Based on the findings of the two studies above, if the patient is a dog presenting with oral repetitive behaviors, a thorough GI workup is also indicated. Additional diagnostics to include in this situation are fecal floatation, preprandial and postprandial serum bile acid measurement, canine pancreatic lipase immunoreactivity (cPLI), abdominal ultrasonography, and endoscopy with biopsy.
Depending on the diagnosis, therapy may include a hypoallergenic diet, antibiotics, corticosteriods, antiemetics, antacids, and anthelmintic drugs. As when dealing with any set of signs in a veterinary patient, establishing a list of differential diagnoses and then allowing diagnostic tests to sort out the true etiology is always warranted before beginning therapy. However, if a thorough work-up is not possible, nonspecific treatment with antacid therapy and a hypoallergenic diet may be beneficial.
Kelly Ballantyne, DVM
John Ciribassi, DVM, DACVB
Chicagoland Veterinary Behavior Consultants
1042 Mountain Glen Way
Carol Stream, IL 60188
1. Overall KL, Dunham AE. Clinical features and outcome in dogs and cats with obsessive-compulsive disorder: 126 Cases (1989-2000). J Am Vet Med Assoc 2002;221(110):1445-1452.
2. Mason G, Rushen J. Veterinary and pharmacological approaches to abnormal repetitive behaviour. In: Stereotypic animal behaviour. 2nd ed. Oxfordshire, UK: CABI, 2006:;286-384.
3. Bécuwe-Bonnet V, Bélanger MC, Frank D, et al. Gastrointestinal disorders in dogs with excessive licking of surfaces. J Vet Behav 2012;7(4):194-204.
4. Frank D, Bélanger MC, Bécuwe-Bonnet V, et al. Prospective medical evaluation of 7 dogs presented with fly biting. Can Vet J 2012;53:1279-1284.
5. Plessas IN, Rusbridge C, Driver CJ, et al. Long-term outcome of Cavalier King Charles spaniel dogs with clinical signs associated with Chiari-like malformation and syringomyelia. Vet Rec 2012;171(20):501.
Case example: Charlie, the snapping poodle
Charlie, a 3-year-old 60-lb neutered male standard poodle, had begun snapping at imaginary items in the air about five months after he had been adopted from a rescue group. The behavior often occurred in conjunction with Charlie's stopping, freezing, and staring as if into space. However, the snapping behavior also occurred separately from this freezing and staring activity. Charlie was also reported to have intermittent soft stools. Treatment with potassium bromide for a possible seizure disorder did not improve the snapping or freezing behavior.
A standard diagnostic work-up—including a physical examination, complete blood count, serum chemistry profile, urinalysis, and fecal floatation—showed no abnormalities. Further work-up, including abdominal radiography and ultrasonography as well as an endoscopic examination to collect gastric and duodenal biopsy samples, was pursued. The results of these tests supported a diagnosis of lymphocytic-plasmacytic enteritis, and treatment with a hypoallergenic diet and metronidazole was instituted. Within a few weeks, the frequency of the fly snapping had diminished, and it had mostly discontinued by about two to three months after therapy began.