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My dog has Horner's syndrome for over a year. Why no improvement?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed Large (61lb +) | Female | spayed | 13 years and 4 months old | 65 lbs

My dog was diagnosed with horners but has been having the symptoms for over a year... is this normal? Her symptoms don't seem to be getting any better. And they are treating with brain and nerve support meds, but that's it.

1 Answer

Most Helpful Answer

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Answered By Anna M., DVM

Veterinarian

Published on June 29th, 2017

Unfortunately, it is impossible to predict to what degree Horners syndrome will resolve. Most dogs have some improvement within a few weeks to a few months of the initial onset, but it is quite common for the dog to maintain some degree of Horners symptoms indefinitely. If you want more information on what is going on, you could ask your vet about referral to a neurology specialist (most universities have this) - but even with referral you may not get a more specific answer unfortunately, since older dogs with Horners most commonly have an idiopathic onset - which means the ultimate cause is unknown. I know it's frustrating not to have a more specific answer than that, but it sounds like you are doing what you can for Ada with the brain and nerve support. Hope that helps!

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