Cerebral metabolism in dogs assessed by (18)F-FDG PET: a pilot study to understand physiological changes in behavioral disorders in dogs.

The positron emission tomography (PET) imaging technique, which is utilized in human behavior and psychiatric disorder research, was performed on the brains of clinically normal mixed breed dogs, 3 hound-type (long floppy ears) mixed breed dogs and 3 non-hound retriever-type mixed breed dogs. Glucose metabolism was obtained with F-18 fluorodeoxyglucose (FDG), and quantitative analysis was performed by standardized uptake value (SUV) measurement. Magnetic resonance (MR) images were obtained in each dog, and these images were superimposed on PET images to identify anatomical locations. The glucose metabolism in each region of interest was compared between the three hound-type dogs and 3 non-hound-type dogs. The two anatomically different types of dog were compared to assess whether breed-typical behavioral tendencies (e.g., sniffing behavior in hound-type dogs, staring and retrieving in Labrador-type dogs) are reflected in baseline brain metabolic activity. There were no significant differences between the hound-type dogs and non-hound-type dogs in cerebral SUV values. These data might serve as normal canine cerebral metabolism data for FDG PET studies in dogs and form the basis for investigations into behavioral disorders in dogs such as compulsive disorder, anxiety disorders and cognitive dysfunction.

Randomized, controlled clinical trial of the efficacy of fluoxetine for treatment of compulsive disorders in dogs.

OBJECTIVE: To evaluate efficacy of fluoxetine hydrochloride for treatment of compulsive disorders in dogs. DESIGN: Randomized, controlled clinical trial. ANIMALS: 63 dogs with compulsive disorders. PROCEDURES: The diagnosis was confirmed on the basis of analysis of videotapes of the dogs' behavior by 3 veterinary behaviorists, results of physical examination and clinicopathologic testing, and, when necessary, telephone interviews with owners. Dogs were randomly assigned to treatment with fluoxetine (1 to 2 mg/kg [0.45 to 0.9 mg/lb], PO, q 24 h) or a placebo. Owners did not receive any advice regarding behavioral or environmental modifications. Severity of episodes was measured through telephone interviews every 2 weeks and on the basis of a daily diary kept by each owner. RESULTS: 42 days after the initiation of treatment, the proportion of dogs with a decrease in severity of the compulsive disorder, as reported by the owners, was significantly higher for dogs treated with fluoxetine than for control dogs, and dogs treated with fluoxetine were significantly more likely (odds ratio, 8.7) to have a decrease in severity of the compulsive disorder. However, mean number and duration of compulsive episodes, as determined from daily diary entries, did not differ significantly between groups. The most common adverse effects were decreased appetite and mild lethargy. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that fluoxetine may be efficacious in the treatment of compulsive disorders in dogs, although results were equivocal. The present study did not examine whether fluoxetine was more efficacious than or synergistic with behavioral and environment modifications.

Canine aggression toward familiar people: a new look at an old problem.

Dogs that are aggressive toward their owners have long been regarded as being dominant. This article presents scientific evidence that does not support this claim. Based on this evidence, the authors present an alternative explanation for canine aggression toward owners and outline a treatment plan.

Effects of reconcile (fluoxetine) chewable tablets plus behavior management for canine separation anxiety.

Canine separation anxiety is a common behavioral problem presented to veterinarians. Associated behaviors are distressing to both dog and owner, have the potential to disrupt the human-companion animal bond, and may lead to euthanasia. The results of this study demonstrate the clinical efficacy and safety of Reconcile (fluoxetine, 1 to 2 mg/kg/day [0.45 to 0.91 mg/lb/day]), in conjunction with behavior management, for the treatment of canine separation anxiety. The beef flavored chewable formulation was palatable to treated dogs and easy to administer. This study provides to veterinarians and owners valuable information about an effective separation anxiety treatment plan that combines use of Reconcile with behavior modification.

Comparative bioavailability of fluoxetine after transdermal and oral administration to healthy cats.

OBJECTIVE: To determine bioavailability, pharmacokinetics, and safety for transdermal (TD) and oral administration of fluoxetine hydrochloride to healthy cats. ANIMALS: 12 healthy mixed-breed sexually intact 1- to 4-year-old purpose-bred cats. PROCEDURE: A single-dose pharmacokinetic study involving 3 groups of 4 cats each was conducted in parallel. Fluoxetine in a formulation of pluronic lecithin organogel (PLO gel) was applied to the hairless portion of the pinnae of cats at 2 dosages (5 or 10 mg/kg), or it was administered orally in capsules at a dosage of 1 mg/kg. Plasma samples were obtained and submitted for liquid chromatography-mass spectrometry-mass spectrometry analysis of fluoxetine and its active metabolite, norfluoxetine. RESULTS: Peak fluoxetine concentration (Cmax) was lower and time to Cmax longer for TD administration versus oral administration. Relative bioavailability of each dose administered via the TD route was 10% of the value for oral administration of the drug. Mean plasma elimination half-life after oral administration was 47 and 55 hours for fluoxetine and norfluoxetine, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: This study provides evidence that fluoxetine in a 15% (wt:vol) PLO gel formulation can be absorbed through the skin of cats into the systemic circulation. However, the relative bioavailability for TD administration is approximately only 10% of that for the oral route of administration.

Diagnosis and management of compulsive disorders in dogs and cats.

This article discusses the presenting signs, diagnosis, and differential diagnosis of compulsive disorder. Problems with the diagnosis and heterogeneity of the condition are discussed. Likely causes, development, and pathophysiology of the condition form the basis for the clinical approach to the treatment of the condition. Treatment includes environmental and management changes, behavioral modification, and drugs.