Naltrexone Use in Dogs

Talk to a vet about management options for your cutie's compulsion.
Duncan Smith/Photodisc/Getty Images

Naltrexone is an opioid antagonist that is occasionally used to manage problematic compulsive patterns in dogs. Veterinarians sometimes prescribe naltrexone for dogs that excessively chase their tails, for example. They also occasionally do so for dogs that compulsively chew, lick or scratch their bodies.

How Naltrexone Functions

As an opioid receptor antagonist, naltrexone functions by obstructing the actions of opioid receptors within dogs' brains. Naltrexone undoes the operations of opioid agonists. Opioids possess painkilling abilities, and because of that are believed to be able to promote compulsive behavioral patterns. When naltrexone diminishes the painkilling properties of opioids, it's thought to make dogs feel uncomfortable, thus stopping them from participating in compulsive actions, whether repetitive chewing or anything of that ilk. If you have any questions about naltrexone and your dog, talk to a veterinarian. Never give your pet any medication without first receiving veterinary permission.

Naltrexone Use

Some veterinarians suggest the use of naltrexone in dogs that have behavioral issues. Dogs with behavioral troubles often take the medication orally. It can also sometimes be administered to them via injection. Studies have shown that naltrexone can be effective for halting compulsive behaviors such as obsessive licking in many dogs -- acral lick dermatitis. However, the medication's ability to stop compulsive patterns is only temporary, with the majority of dogs reverting back to their old ways within weeks or months after taking it.

Negative Side Effects

Negative side effects of naltrexone in dogs are thought to be few, according to Stephen R. Lindsay, author of "Handbook of Applied Dog Behavior and Training, Procedures and Protocols." Excessive sleepiness is a possible effect of naltrexone, for one. Unusually uncommunicative and reclusive behaviors are another possibility with naltrexone in dogs. Skin problems can occur, too, specifically pruritus. Pruritus is a medical condition that is characterized by extreme itchiness. People are occasionally prescribed naltrexone for dependence on opioids. Side effects in humans aren't common, but include throwing up, nausea, anxiety and sleeplessness. As with dogs, pruritus is a potential side effect for humans who use naltrexone.

Other Uses

In the animal realm, naltrexone, which is often classified as an anti-obsessive medication, isn't only used to manage behavioral troubles in canines. It's also commonly employed to undo the actions of strong opioids that render wild or big animals motionless. Naltrexone also has been offered to horses that exhibit compulsive and repetitive behaviors such as crib-biting, according to Sharon L. Crowell-Davis and Thomas Murray, the authors of "Veterinary Psychopharmacology." When horses crib-bite, they grab onto things like fences and tug against them using their incisors. They also curve their necks and swallow air. As a compulsive pattern, crib-biting is generally brought upon by frustration, stress and boredom.