Abstract

At three years of age, a neutered male California sea lion began exhibiting a stereotypic behavior pattern that consisted of sucking on his left flank, regurgitating food, and re-eating it. The abnormal behavior continued over the next two years. During this time, the animal gained weight at a similar rate as three other pups of the same age. Beginning at age 5, however, his weight dropped from a peak of 124 kg to 100 kg in two months. Hematology and serum chemistries were normal. However, two weeks later, a recheck revealed the hemoglobin had dropped from 18.0 to 10.5 grams per deciliter (g/dl). All other hematologic indices, as well as fecal cytology, were normal. Radiographs and ultrasound were unrewarding. He was treated for possible gastrointestinal ulcers even though none were visualized during gastroscopic examination. Antibiotics and antifungals were given prophylactically. In an effort to break the behavioral pattern, diazepam was administered at 0.22 milligrams per kilogram (mg/kg) for seven days without success. Prednisolone at 1.4 mg/kg twice a day for 14 days, decreasing the dose over the next 50 days was used without success. A follow-up exam two months later revealed his hemoglobin had returned to 16.8 g/dl. Metoclopramide at 0.33 mg/kg every twelve hours, thirty minutes before feedings was used for 7 days in an attempt to control regurgitation and weight loss, again without success. After 12 months of various treatments, from age 5 to 6, his hemoglobin began to drop again. Total reticulocyte count increased from 0.1 to 3.9% during the episodes of falling hemoglobin. Total red blood cell counts dropped from an average of 4.56 x 10⁶/mm³ to 2.3 3 x 10⁶ /mm³ during these episodes. The hemoglobin fell from 16.8 g/dl to 9.6 g/dl in twelve weeks. Two weeks later, it was down to 6.8 g/dl. Gastroscopy revealed a stomach full of a chocolate colored fluid that was positive for hemoglobin. His stools were dark and tarry. He was treated for blood loss anemia and ulcers with antibiotics, hematinics, and histamine H₂ antagonists.

A gastrointestinal barium series using a 2:1 ratio mixture (water to barium) of barium sulfate at 4.4 ml/kg of body weight revealed a gas-filled bowel with a transit time of two hours. A 30 day course of amoxicillin/clavulanic acid was added to the treatment program. Over an 8 week period, his hemoglobin increased from 6.8 to 10.9 g/dl. However, his weight dropped from 100 to 87 kg. Considering a diagnosis of psychosis, fluoxetine HCI, a serotonin reuptake inhibitor, was administered at 1.2 mg/kg once a day for 63 days. The dose was then reduced to 0.2 mg/kg once a day for 163 days. By the 118^th day after initiating treatment, the animal had gained 42 kg, reaching a peak weight of 156 kg. The flank sucking behavior also diminished. However, from the time the peak weight was reached, the abnormal behavior slowly returned to the pre-fluoxetine HCl level. Over the next 5 months, the animal's weight dropped from 156 kg to 86 kg. At this time, hematology, serum chemistries, and fecal cytology were normal. Finally, at the age of 8 with the working diagnosis of a psychotic disorder, we elected to try haloperidol, (antipsychotic agent) at a dose of 0.11 mg/kg twice a day. The animal gained 22 kg in 12 days. The behavior of flank sucking and regurgitating diminished dramatically. Currently, the sea lion continues to maintain or gain weight.