Left pupil not constricting

[spamgirl]

Hi again,

I hope all is well with you! We have a new problem with one of my dogs. This time his left pupil is not contracting. I noticed that the sclera was red, so I took him in to the vet and she prescribed maxidex for a week, but she said she noticed his left pupil wasn't constricting and the right had a weak response to light. I just tested and the right actually had a quite strong response, so maybe it was because he was excited that it wasn't responding in her office, I'm not sure, but the left one does not respond at all - not so much as a twitch.

I'm going back in a week and she's going to check it again, but I was wondering - what could cause this? I did some Googling around and didn't find many answers specific to dogs.

Thanks, as usual, for your help!

[Traci]

How old is he?

Do you know if he had any sort of mild trauma recently? (something happen outdoors in the yard or anything?) - is he otherwise healthy and no other illness present?

Anisocoria can be caused by various things from something as mild as uveitis to more serious conditions such as glaucoma or cancer to various things in-between, some depending on natural aging of the dog.

Redness and potential swelling could be uveitis, but vet needs to rule out underlying causes TO the uveitis. Did she perform an eye pressure test or a fluorescein dye to fully examine the cornea and rule out ulcers, nerve issues, etc? These would be the first and foremost tests to be done to rule out ulcers, scar tissue, retinal or corneal injuries, glaucoma etc. Beyond those two tests, it would be more helpful to get an exam with a veterinary opthalmologist (most vets have a visiting one, or will refer you), providing that your dog is otherwise in excellent health with no pre-existing conditions, since anything pre-existing would need to be detected and ruled out as a cause for the eye issues.

Watch him carefully, and observe for any other changes or worsening of his left eye (i.e., more swelling, redness, discharge, irritation such as him rubbing at the eye, pain, reluctance to be outside or in bright sunlight etc), and if anything occurs, don't wait for the week's end of medication treatment, get him back in immediately for a more complete exam or immediate referral to an opthalmologist. Sometimes, if a severe injury occurred, it's best to get advanced diagnostics/opinion by an opthalmologist in order to treat and prevent further damage.

Hopefully, this isn't anything serious, but don't wait to find out - watch him carefully this week, and again, if symptoms worsen or new things develop, get him seen immediately.

[spamgirl]

How old is he?

Do you know if he had any sort of mild trauma recently? (something happen outdoors in the yard or anything?) - is he otherwise healthy and no other illness present?

Anisocoria can be caused by various things from something as mild as uveitis to more serious conditions such as glaucoma or cancer to various things in-between, some depending on natural aging of the dog.

Redness and potential swelling could be uveitis, but vet needs to rule out underlying causes TO the uveitis. Did she perform an eye pressure test or a fluorescein dye to fully examine the cornea and rule out ulcers, nerve issues, etc? These would be the first and foremost tests to be done to rule out ulcers, scar tissue, retinal or corneal injuries, glaucoma etc. Beyond those two tests, it would be more helpful to get an exam with a veterinary opthalmologist (most vets have a visiting one, or will refer you), providing that your dog is otherwise in excellent health with no pre-existing conditions, since anything pre-existing would need to be detected and ruled out as a cause for the eye issues.

Watch him carefully, and observe for any other changes or worsening of his left eye (i.e., more swelling, redness, discharge, irritation such as him rubbing at the eye, pain, reluctance to be outside or in bright sunlight etc), and if anything occurs, don't wait for the week's end of medication treatment, get him back in immediately for a more complete exam or immediate referral to an opthalmologist. Sometimes, if a severe injury occurred, it's best to get advanced diagnostics/opinion by an opthalmologist in order to treat and prevent further damage.

Hopefully, this isn't anything serious, but don't wait to find out - watch him carefully this week, and again, if symptoms worsen or new things develop, get him seen immediately.

He is 13 and no injuries recently - he's old and sedentary. The vet ran both a pressure test and the staining and both came out normal, thankfully. Otherwise, his only problems are that his kidneys don't function optimally (but he is not in renal failure) and he has significant arthritis. He also tore his knee a number of years back, but that healed and hasn't caused further issues. The only medication he takes is a cartrophen shot - he was on gabapentin because he broke a claw right at his foot, but he went off it last week.

The drops seem to be working as the redness and swelling has subsided. It was so bad I could hardly hold his eye open last night, the eyelids were swollen in the way. But the pupil still isn't dilating. I'll watch him carefully - thanks for your detailed advice!

[spamgirl]

Hi again,

So the redness was treated quickly, but both eyes are still unreactive to light 6 months later. No uveitis, no glaucoma. Any ideas?

Thanks as always!

[Traci]

I strongly advise you get a quick appt with a certified vet ophthalmologist - they would be more familiar with what other testing could be done to confirm or rule out something. I would also advise checking out heart function and getting blood pressure checked - with this, it's best to get at least 3 readings in the same exam to gauge a median blood pressure number, this can be done with the ophthalmologist. Please don't wait on this, if he's been on treatment, and he didn't respond (other than for redness/swelling), it's really time to have a specialist take a look.

[spamgirl]

Hi Traci,

I wanted to thank you again for all your help over the years. Just six months after his brother, my Popo has passed at the age of 15. He was blind, deaf, had trouble walking, and finally the pain was too much. You have been a blessing to me when I needed help most. Thank you.

[Traci]

****TEARS****
I'm so very sorry to hear this! If only they could live with us forever, I know that Ami and Popo meant everything to you, and know this hasn't been easy for you with them so close together. You went far and above for both of your little guys and I know they knew how much you loved them.

Safe and gentle journey, sweet Popo, run free with Ami, together again (((((HUGS))))) ... my thoughts and prayers are with you!!