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My active dog is losing muscle, especially on one side. What's wrong?

Updated On September 23rd, 2025

Pet's info: Dog | Border Collie | Male | 4 years old

Trick has lost a lot of muscle despite being active and doing daily walks and exercises to keep him fit and strong he also does hydrotherapy but had not been for 4 months because he had wounds so couldn't swim what could cause this he is on daily previcox and codeine when needed and monthly arthropen jab it gone from both front and back legs right side is most affected am concerned he has lost muscle but continues to be active what can I do does he need serious investigations done

1 Answer

Most Helpful Answer

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Answered By Dr. Heidi DVM, CVA, CCRT, CVTP, CVSMT, CVCH

Veterinarian, Certified Veterinary Acupuncturist, Certified Canine Rehabilitation Practitioner

Published on June 21st, 2018

The most common reason that we will see symptoms like you are describing of a loss of muscle in all legs, but being more affected on one side would be a problem in the nervous system. Most commonly, we will see problems in the neck that affect one side more than the other. I would start with having your veterinarian examine Trick again and perform a full neurological examination. Depending on their findings, the next step may be a consultation with a neurologist. If Trick is only 4 years old, then it is certainly worth doing additional testing to determine what is doing on and if additional treatment could help prevent further muscle loss. Although we can certainly see muscle loss from arthritis, it rarely involves all 4 legs and is not often so asymmetrical that you can tell that one side of the body is worse, so I think it is worth consulting with a neurologist. Good luck! I hope that was helpful. Thanks for using Petco Pet Education Center, formerly Petcoach.

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