My cat's left eye has its pupil dilated

[vale1979]

She has 3 dias with her left pupil dilated. At darkness her both eyes look normaly dilated but in daylight her pupils have diferent sizes (the left is larger)
I took her to the vet on saturday, the vet found her healthy, without fever or with a signal of being sick, just with her left eyelid a bit swollen and  suggested me to go to an ophthalmologist. I made an appointment for today. but I'm too worried. She eat, walk and act normaly in fact she doesn't look to be sick just has her left pupil look strange and is always dilated.

i'm afraid for her, maybe she has leukemia and is going to die.

ps: sorry by my english, I'm a spanish speaker.

[vale1979]

Hi! thanks for your answer.

I took my cat to the ophthalmologist, she found keratitis and conjunctivitis in her eye. She suspects that probably my cat has an infection for chlamydia, since I told her that mafalda (my cat) catched a cold two weeks ago. regarding to my cat's dilated pupil the vet found it working well, since with the flashlight test both pupils were contracted. Besides in the vet's office my cat has her both pupil dilated for being stress or nervous and I went to the vet at night. the problem in her pupil is more evident with daylight. Well, vet gave us a treatment for the keratitis and the conjunctivitis with Doxycycline and eye drops that contains tobramycin. she told us that keratitis or conjunctivitis don't cause mydriasis, so probably she will have to do  some medical examinations to my cat. My vet have not test my cat for leukemia or for feline aid yet, because I told her that I had cats infected with leukemia so probably Mafalda also is infected.
Mafalda is still acting normaly, despite her pupil dilated, she is still eating and looking healthy. Mafalda is going to go to the ophthalmologist's office next monday for a medical check.

Thans Doctor.

[Aleda M Cheng, D.V.M., C.V.A]

Did you take her to the ophthalmologist today?  Did your regular vet test your cat for feline leukemia and feline Aids?  Unequal pupil size is called anisocoria.  I answered a similar question in June, 2007 which I have copied below.  Please let us know what the veterinary ophthalmologist finds!    

Cornell College of Veterinary Medicine lists 54 causes of feline anisocoria.
Although your cat has no symptoms now other symptoms could develop over time, unless your cat was born with the condition and you never noticed it before?

The list of causes can be summarized into the following broad categories: infection (bacteria, fungal, or, viral), toxin ingestion, brain neoplasm (cancer), congenital or hereditary defects, insect infestation (bot, or cutebra), traumatic injury to the head, vitamin deficiency, autoimmune, and others.  I urge you to seek help for your cat and please leave me an update.  Thanks and Good Luck!

The following is the complete list of 54 causes of feline anisorcoria pasted from Cornell College of Veterinary Medicine Consultant list:


54 Possible Diagnoses
o Babesiosis, babesia, in dogs and cats
o Bacterial, vegetative, infective, endocarditis in dogs and cats
o Blastomycosis, blastomyces dermatitidis, in dogs and cats- zoonosis
o Blood transfusion reaction in dogs and cats
o Bromethalin toxicity in dogs and cats
o Cerebellar or pericerebellar abscess
o Cerebellar or pericerebellar brain neoplasia, tumor, cyst
o Cerebellar trauma, hematoma, or ischemia
o Cerebral or pericerebral brain neoplasia, tumor, cyst
o Chronic corneal epithelial defects, indolent ulcer
o Coccidioidomycosis, coccidioides immitis in dogs and cats, valley fever- zoonosis
o Congenital and/or hereditary deafness in dogs and cats
o Congenital retinal detachment in puppies, kittens, and foals
o Cryptococcosis in dogs and cats- zoonosis
o Cuterebra, dermatobia, infection in dogs and cats
o Dysautonomia or dilated pupil syndrome in dogs and cats
o Feline immunodeficiency virus, fiv
o Feline infectious peritonitis, fip, enteritis, coronavirus, fcov
o Fungal, mycotic keratitis, keratomycosis
o Glaucoma in the cat
o Hemifacial spasm in dogs and cats
o Hydrocephalus, hydranencephaly
o Idiopathic tonic pupil, pupillotonia, in dogs and cats
o Injury, trauma, to optic disk (disc) or nerve
o Intraocular parasite, ophthalmomyiasis interna, in dogs and cats
o Ischemic encephalopathy in cats
o Keratoconjunctivitis sicca in dogs, cats, and horses
o Lens induced, phacoclastic, phacolytic, uveitis in dogs and cats
o Lens luxation, subluxation, displacement, dislocation in cats
o Lymphosarcoma, lymphoma in cats, feline leukemia virus, felv
o Meningoencephalitis, meningitis, meningoventriculitis
o Metastatic ocular neoplasia in dogs and cats
o Muscular dystrophy in cats
o Neurotrophic, neuroparalytic, keratitis
o Ocular, corneal, trauma, injury, proptosis of the eye, orbit
o Optic nerve hypoplasia
o Orbital, retrobulbar neoplasia, cyst in dogs and cats
o Orbital, retrobulbar, cellulitis, abscess, foreign body in dogs and cats
o Otitis externa, media, interna, para-aural abscesses, in dogs and cats
o Peripheral vestibular neoplasia in dogs and cats
o Ponto-medullary, brain stem trauma or thrombosis, hematoma
o Ponto-medullary, brain stem, pituitary, inflammation, abscess
o Ponto-medullary, brain stem, pituitary, neoplasia, cyst
o Portosystemic shunts, hepatic microvascular dysplasia, in dogs and cats
o Prenatal or perinatal asphyxia
o Progressive retinal atrophy, degeneration, in dogs and cats
o Pseudorabies, aujeszky's disease, suid herpesvirus 1 in species other than pigs
o Pupillary dilation resembling pourfour du petit syndrome in cats
o Snake bites, snakebites
o Thiamine, vitamin b1 deficiency in dogs and cats
o Toxoplasmosis, toxoplasma gondii, in cats- zoonosis
o Trigeminal neuropathy, idiopathic neuritis, in dogs and cats
o Ulcerative canine or feline keratitis, corneal ulcer
o Urinary incontinence, feline genitourinary dysplasia, urethral hypoplasia