A parasite most people file under “cat problem” can damage a dog’s eyes. A new case series from the ophthalmology department at the Hebrew University’s Koret School of Veterinary Medicine describes five dogs with eye disease tied to Toxoplasma gondii, the protozoan that reproduces in cat intestines and spreads through feces.
The dogs were treated at the university’s teaching hospital in Rehovot from 2023 to 2025. All five had inflamed eyes and positive antibody tests. In three, repeat testing showed antibody levels rising fourfold, pointing to a recent infection. Damage ranged from mild inflammation at the front of the eye to retinal detachment and blindness. One lost an eye to glaucoma. Another arrived blind in both eyes, got its sight back, and kept permanent retinal scarring.
The strangest case was an eight year old Weimaraner that developed severe eyelid inflammation after an earlier bout of eye trouble. The authors believe it may be the first reported link between that eyelid disease and toxoplasmosis in a dog.
All five improved at first on clindamycin, the standard treatment, and anti-inflammatory drugs. Two relapsed anyway, antibody levels staying high through a long course. Several had other illnesses or took immune suppressing drugs, which may have let the infection take hold.
What this means for your dog
Antibodies alone do not prove the parasite did the damage, and five dogs is a small sample. Unexplained redness, squinting or a dog that bumps into furniture deserves a vet visit, and toxoplasma is worth raising if your dog is already ill or takes immunosuppressants. Keep dogs out of the litter box and skip raw meat. A steroid shot gave one beagle his sight back, which shows how much an eye can recover. The full case series is in Veterinary Parasitology: Regional Studies and Reports.