Sarah Wilson

Dog Expert

Sudden Dog Aggression Towards Other Dogs. Why?


Sudden Dog Aggression Towards Other Dogs Image“I’ve got a 4 year old female mutt (plott hound mix) and an 8 month old female lab. Now that winter is over, we are out all together more. Dogs that my 4 year old mutt used to LOVE have now become a target for her aggression. It’s almost like she is protecting the puppy? This dog has not history of aggression toward other dogs. The first time I heard her growl at another dog was a relative’s untrained male (who outweighs her by about 20lbs) wouldn’t stop jumping on her. We were all shocked that she did it….”

Why the sudden dog aggression towards other dogs? There is a common reason for this and yes, the younger dog is probably part of the issue, but not in the way the questioner thinks.

What’s going on? I bet the older dog is sore. Ouchy. Hurts.

Why did this start now? It’s spring. That 8-month-old puppy is full of energy and these two are outside racing around and wrestling—probably for hours a day. Some underlying issue with the older dog is being stressed or she has a mild strain from all the play—who knows— but this increase in activity=ouch!

Enter the relative’s bigger, mosh-pit-approach-to-life dog. He is rough and hurts her. Because no one else helps her, she has to set the boundary herself and growls.  I give her a lot of credit that she only growled. I never expect my dogs to tolerate being harassed; I step in on their behalf and stop it.

Other clues of soreness include a dog:

  • Sitting up before standing up from lying down.
  • Not jumping up or hesitating to jump up on beds or couches she used to sleep on all the time. Ditto getting into the car.
  • Hesitating at stairs.
  • Lying around more.
  • Lying under things more.
  • Not walking as far or playing as long.
  • Playing briefly then getting “snarky”.
  • Remaining friendly to calm, older, polite dogs but aggressing at pushy, “rude”, rough, young dogs.
  • Swinging their head toward your hand when you stroke their back or haunches.
  • Sitting “weirdly” or in some new position.

What to do?

  • Get to her veterinarian. There are many reasons for soreness: injury, orthopedic problem, tick-borne disease, low thyroid and more. Only your veterinarian can sort out which, if any, of these things is going on.
  • Supplement her with good joint supplements. Give her body what it needs to heal.
  • Limit her play with the younger dog. No wrestling or racing on slippery surfaces. No rough, slam and roll type games. Don’t allow her to be hassled when she’s resting.
  • Set up her crate. At four she’s probably been out of her crate for a while but start giving her enforced rest daily.
  • Skip play with others. She used to like it; I used to like the playground. As an adult, it holds little appeal and she may well be in the same boat.
  • Take her word for it. If she still likes her calm friends but is all teeth with the full-contact crew then believe her and wave to those dogs/people from a distance.

Take home lesson for everyone? Any sudden behavior change in an adult dog, such this dog aggression towards other dogs, often has a medical cause. Hopefully, changes in this dog’s daily routine, everyone’s expectations and some good veterinary care will get this dog back to normal quickly.

Now you know.

Related blogs:
Seeing Pain: Hindquarters
Why is My Dog Scared of Slippery Floors
Dog Arthritis: 3 Ways to Help with Debbie Gross Saunders





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