Vol. 5 No. 1 (2019)
Case Report

A case of aggressive behavior in a mongrel dog

Published 2019-05-23


  • dog,
  • fluoxetine,
  • territorial aggression,
  • reactivity


A male mongrel dog, two years old, was evaluated for aggression and reactivity to environmental stimuli. The dog was a stray dog; in March 2016 the current owner decided to adopt him. In May 2016 the owners decided to contact a veterinary behaviorist for instructions on how to introduce the dog into the new home, with another dog and to control the high level of his reactivity. The animal, in fact, often barked to dogs, people and cars.

A diagnosis of predatory aggression, territorial intraspecific aggression towards unfamiliar dogs, situational anxiety disorder was made. It was recognized as the basis of aggressive behaviors, a component of stress and anxiety, worsened by previous experiences. A significant impulsivity of the dog was also identified which made the management of aggression difficult.

Fluvoxamine (1.5 mg / kg bid) was prescribed, in view of the final move to the new home. The owners were advised to start, with a dog trainer, a rehabilitation program aimed at: implementing the relationship, improving communication and reading the dog's signals, reducing conflicts and potentially critical situations. At the first follow up the owner reported that, although there was an improvement in the intensity of the symptoms, the dog appeared slightly worse in interspecific relationships: he had bitten both owners. At the second follow up the interspecific aggressiveness was decidedly worse, and two episodes occurred again. In general, the dog appeared to be much more intolerant of manipulation even by owners than in the past. It was decided to modify the pharmacological prescription, replacing Fluvoxamine with Fluoxetine (1 mg/kg sid).

At the third follow up, the dog was decidedly improved. The owners referred the dog was able to rest better during the night and daytime hours, to relax more at home. The animal tolerated better the interactions with the owners. It was therefore decided to gradually wean from the drug. The owners decided to reduce the meetings with the dog trainer, until their complete interruption.  At the last follow up, the improvements in inter and intra-specific relations were relevant.

The owners understood that despite the behavioral rehabilitation process and the pharmacological treatment, the dog presents behavioral problems that must be managed carefully, respecting its ethological needs.