NMVMA listserve Veterinary Behavior Tip #14

 Jeff Nichol, DVM – Veterinary Behavior Medicine
Veterinary Emergency and Specialty Centers

Albuquerque and Santa Fe Pain-related aggression

During my behavior residency it was drummed into my head that medical differentials come first. A review of the patient’s medical history, current lab results, and physical exam findings are essential to an accurate behavioral diagnosis. There are lots of pathologies that can influence behavior; I’ve commented on a few of them in the past. Pain, as an underlying cause of aggression, can be easily overlooked.

We’ve all been taught the signals of panting, tense body postures, whining, and avoidance. We also know that with the stress of being examined in a veterinary clinic the adrenalin rush can obscure these indicators. This can make an analgesic drug trial valuable for at-home use in some cases.

There are pets who develop anticipatory pain responses, further challenging our abilities to read their minds. These are cats or dogs who have learned by experience that if that @#%&* toddler plows into them again they will have to dodge the blow and confront the predictable pain associated with their evasive maneuvers. These animals can become hyper-reactive, lunging and snapping first, leading their owners to label their aggression as “unprovoked”.

I hear that term often from my behavior clients. Once the history is fully elucidated, at-home videos assessed, and the pet examined for areas of discomfort the arousal/aggression triggers can almost always be identified. Pets whose suspected pain may be causing reactive aggression may benefit from more than analgesics and anti-inflammatories.

We like gabapentin because of its analgesic and its anxiolytic effects.

Gabapentin dose:

  • Cats: 12.5 mg/cat BID.
    • Can go as high as one 100 mg capsule/dose for reduced anxiety and moderate sedation prior to veterinary visits.
    • Cats eat it readily on some favored food followed by regular food.
  • Dogs: 25-60 mg/kg divided q 6-8h. Dose can be gradually increased.

Clonidine has been helpful for highly reactive dogs who may be painful. Clonidine inhibits the release of norepinephrine and decreases sympathetic tone. As an alpha-2 agonist, related to Dexdomitor, clonidine has analgesic and calming properties. It can be good for post-operative use in dogs.

Clonidine dose:

  • Dogs: 0.026 mg/kg (0.01-0.05 mg/kg) BID – TID.
    • For large dogs 0.3- 0.9 mg. BID – TID
    • Clonidine takes 2 hours to become effective and lasts 4-6 hours.
    • Can be used with SSRIs and TCAs.
    • Works well for dogs who won’t go to sleep and those who are reactive on leash walks.
  • Can reduce blood pressure and heart rate.
  • Rebound hypertension can be avoided by slowly withdrawing treatment.
  • Available as 0.1, 0.2, and 0.3 mg tablets

Since gabapentin and clonidine are both off-label drugs in pets client consent should be obtained. If you try them and have concerns or questions you are welcome to contact me.

All the best,

Jeff Nichol, DVM
Veterinary Behavior Medicine
505.792.5131