Why is my cat's one eye dilated after shots and ear cleaning?

This is called anisocoria, and it is a medical emergency when it occurs suddenly. Munna could be experiencing an abnormal reaction to the vaccines if this happened after he received them yesterday. I would have him seen by a vet immediately.

It is really hard to tell by the pictures but I think one of her pupils is small and the other is dilated. This is called horners syndrome. Sometimes we are unaware of the cause but it can be linked to ear infections. I would recommend taking Lily to the vet to make sure she does not have an inner ear infection. It is possible she has an ear infection (inner or outer) with ear mites. Horners syndrome usually resolves with time but a ear infection would need antibiotics.

It may be from some past head trauma. Glaucoma is usually painful and I would expect him to be squinting. Horner's usually causes a droopy eyelid and sometimes that side of the face isn't normal and sometimes also droopy. If he isn't squinting and seems to be okay, then I wouldn't be too concerned especially since he is a stray and treating him may be nearly impossible. It would be best if the vet can take a look at it while under anesthesia to ensure there isn't any major trauma to the eye or a corneal ulcer. Being that it is a spay/neuter clinic, they may not be able to do much but they could recommend if you need to take it to another clinic to have it looked at again. I hope this helps!

Sometimes vaccines can result in some discomfort and lethargy, but usually only for 24 hours or so afterwards. If it has been longer than that since she was vaccinated it is unlikely to be due to the vaccines. If one pupil is consistently larger than the other that is abnormal however and I would recommend you take her back to the vet to be checked out.

There is anisocoria (the two pupils are unequal in size) and possibly ptosis of the upper eyelid (the eyelid cannot open normally) on the left side (where the pupil is bigger). There are many causes that can provoke this presentation: -Corneal injury such as an ulcer. -Disease or injury to the brain or to the nerves running to the affected eye, such as Horner’s syndrome. -Glaucoma, a disease in which there is increased pressure within the eye (the pupil in the affected eye will be dilated). -Uveitis, or inflammation of the interior of the eye (the pupil in the affected eye will usually be constricted). -Retinal disease. -Scar tissue formation between the iris and the lens (called posterior synechia), a condition that may develop following uveitis. -Iris atrophy (a decrease in the amount of tissue within the iris) usually a degenerative change associated with aging. -Congenital defect of the iris, in which the iris tissue does not develop properly. -Cancer within the affected eye. -Spastic pupil syndrome - a syndrome that may be associated with feline leukemia virus infection. -Other infectious diseases such as feline immunodeficiency virus or toxoplasmosis. Unfortunately is difficult to be more specific than that and a clinical examination at your local veterinarian is essential to confirm these clinical suspicions and treat appropriately. Antibiotics may be needed. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further. If this answer was helpful please let us know, this will be used to improve our service!

What Lucifer is experiencing may be symptoms of an allergic reaction. Other medications (such as topical flea/tick treatments) can sometimes cause this type of a reaction as well. Because this behavior is unusual, it would be a good idea to go in for a recheck exam with your veterinarian just to be safe.

By your description, it sounds as though Orion may have developed Horner's syndrome or other neurologic deficit, or is having an abnormal reaction to his anesthesia or pain medications. This is not typically a normal post-anesthetic finding, but I just read a few rare reports of cats developing Horner's syndrome after anesthetized dental cleanings. Call your vet to discuss Orion's clinical signs so that he can have a full neurologic exam performed.