My Dog Attacked My Other Dog After a Vet Visit – Yikes!

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I received an Ask a Behavior Consultant inquiry last week that said, “My younger Shepherd brutally attacked the older chow mix after the chow got back from the vets office. The only other time Shepherd has smelled that smell was when older dog started having seizures and we took him to this new vet.”

This isn’t the first time I’ve heard of aggression between familiar dogs after one returned from the vet.

I don’t think there’s any good literature on why this happens, but it probably has to due with a difference in scent (that surgery scent may be scary to the at-home dog) and potentially “off behavior” from the dog that just had surgery or a veterinary procedure.

Why Does My Dog Attack His Housemate After the Vet?

Dogs know each other via scent. If one dog comes home reeking of surgical chemicals (which may have a scary or upsetting connotation to the other dog), this alone can trigger a fight. Those vet-smells can be very powerful!

Dogs post-surgery or post-anesthesia also act downright strange. They wobble, stare, and glaze over easily. For a sensitive dog, this odd behavior can be perceived as a threat.

Try not to overthink your dog’s behavior too much. Attributing attacks to status-seeking behaviors (alpha, pack status, etc) rarely helps us understand how to treat aggression cases.

Stick to the principle of parsimony: the simplest explanation is often correct. Here, we’ll go with the assumption that the dog returning from the vet smells or acts weird, triggering a response in the other dog.

That requires less mind-reading than assuming that one dog senses weakness in another and is seizing his chance to rule the roost.

Besides, it doesn’t matter much – our treatment plan doesn’t really rely on knowing exactly what’s going on in your dog’s head.

If The Post-Vet-Visit Fight Was Minor…

If the dogs didn’t cause any damage to each other (aside from potentially small, superficial scratches), and they seem fine the next day, I wouldn’t worry too much. Just keep an eye on them, try to do fun things together but separate them when they’re tired or stressed.

If The Fight Was More Serious…

If the vet-going dog needs to return to the vet, reintroduce them more carefully next time.

I suggest keeping them separate until the post-vet dog is fully alert and behaviorally normal AND doesn’t smell like the vet’s (likely the next day), then doing a parallel walk.

However, if the fight post-vet resulted in injury (especially if one or both dogs required stitches) or the dogs remain tense the next day, then we ought to treat this more like a dog-dog aggression case.

Being overly cautious rarely hurts in this situation!

In that case, here’s how I’d approach this case of dog-dog aggression after vet visits.

Keep in mind that any time one dog causes injury to another, it’s time to get a Certified Dog Behavior Consultant or Vet Behaviorist or Applied Animal Behaviorist involved (not just Alex the Obedience Trainer from down the street).

The Basics of Fixing Dog-Dog Aggression

This is just a broad overview of the general steps I’d take – there are a lot of nuances to treating dog-dog aggression that I simply cannot detail here, especially without knowing the specifics of your case.

  1. Keep the dogs separated unless you’re actively training. You can crate-and-rotate the dogs or simply use doors and baby gates to keep them separate. If the fight was serious, use at least two levels of safety (crate + door, baby gate + tie-down, 2 doors, etc).
  2. Take the dogs on parallel walks together in neutral territory. Keep them separated further than their leashes will reach as necessary.
  3. Reward the dogs for glancing at each other. This will start teaching them that their old housemate = treats and will teach them that calmly looking at their housemate is an option.
  4. Gradually reintroduce them inside the house directly post-walk. You might need to do several walks before taking this step – go slow! It’s far easier when the dogs are “warmed up” with the walk, a bit tired, and therefore more relaxed. Use a muzzle at this step if the fight was serious – better safe than sorry.
  5. Continue supervising the dogs whenever they’re together. If you’re watching TV or doing the dishes, that doesn’t count as supervising.
  6. Try to stay relaxed in your tone of voice and body posture while remaining vigilant for places to intervene.  The Dog Decoder app is a great way to learn a bit more about those subtle body language cues that you need to watch out for.
    1. Taking Bill Campbell’s advice, I often “jolly up” a dog if I notice stiffness. For example, Dog A is starting to stare at Dog B with a tight mouth, dilated pupils, and a still body posture. Uh-oh! Instead of chastising Dog A or waiting for the fight to actually break out, I happily call Dog A’s name over, squeaking happily and telling him how awesome he is. This usually snaps the dogs out of it far more effectively than reprimanding them (which can backfire).

If you’d like more help understanding and treating your dog’s aggression, check out our e-book on treating aggression in dogs.

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