Ocular diseases of llamas: 194 cases (1980-1993)

OBJECTIVE: To identify ocular and adnexal diseases to which llamas in North America are susceptible, to determine prevalence of these diseases in llamas, and to compare prevalences of the major ocular diseases of llamas, cattle, and horses. DESIGN: Retrospective study. ANIMALS: 194 llamas, 4,937 cows, and 11,950 horses with ocular disease. PROCEDURE: Medical records of all llamas entered into the Veterinary Medical Database between 1980 and 1993 were reviewed. Data on ocular structures affected and types of ocular disease were compiled. Prevalences of uveitis, corneal ulcers, and ocular squamous cell carcinoma in llamas were compared with prevalences in cattle and horses. RESULTS: 194 of 3,243 (6%) llamas had at least 1 ocular disease. The proportion of llamas that had ocular disease was significantly higher than the proportions of cattle or horses. The most frequently affected ocular structure in llamas was the cornea, and ulcerative keratitis was the most common corneal disease. The second most commonly affected structure was the uveal tract. Cataracts were reported in 20 (10%) of the llamas with ocular problems. Eyelid disorders, retinal diseases, glaucoma, and ocular or adnexal neoplasia were reported infrequently in llamas. CLINICAL IMPLICATIONS: Results suggest that corneal disease is common in llamas and is usually secondary to trauma. Uveitis may also be common in llamas, but llamas do not appear to be highly susceptible to glaucoma, ocular neoplasia, or to direct corneal invasion by bacteria such as Moraxella sp.

Update on llama medicine. Ophthalmology.

Review of the limited literature on camelid eyes suggests they are anatomically similar to those of domestic livestock species, except they lack meibomian glands and have iridial folds (rather than corpora nigra). The microbial flora of the healthy camelid conjunctival sac also appears to be similar to those of domestic livestock and pets, except that no Mycoplasma have been isolated from camelids. Ocular diseases for which camelids are presented to veterinarians are numerous and varied. The most frequently presented conditions are ocular trauma and congenital abnormalities. Trauma to cornea, conjunctiva, eyelids, and sclera has been reported. Therapies for these injuries are the same as for other animals. Most congenital abnormalities are cataracts and optic nerve colobomas, but congenital eyelid defects, conjunctival cysts, and multiple ocular defects have been reported. Although these conditions are not demonstrably hereditary, breeding of animals with congenital ocular defects is strongly discouraged. Intraocular inflammatory diseases are seen commonly in camelids. Uveitis and chorioretinitis may cause permanent visual loss, usually with no indication of cause. Equine herpesvirus 1 has been isolated from camelids with severe ocular inflammation and is a known cause of chorioretinitis and neurologic abnormalities. Systemic aspergillosis causes severe chorioretinitis in alpacas. More research is needed to improve our understanding of ocular physiology and pathology in camelids. Genetic studies also are needed to establish hereditary patterns of ocular maldevelopment. Additional information from researchers and practitioners should improve our ability to recognize and treat ocular disease in camelids.

Ocular manifestations of a metastatic pulmonary adenocarcinoma in a cat.

A primary pulmonary bronchogenic adenocarcinoma originating from an intramediastinal accessory lung was diagnosed in a 14.5-year-old cat. The cat had been admitted because of a cloudy right eye. Physical examination revealed a thin cat with severe iritis, aqueous flare, and a fibrin clot in the anterior chamber of the right eye. Right fundic examination revealed bullous retinal detachment superior to the optic disc. Euthanasia and necropsy were requested when FeLV test results were positive. Metastatic neoplastic cells similar to those of the primary tumor were detected in the choroid, ciliary body, and ciliary processes of the right eye. Ciliary and iridic stromal necrosis attributable to neoplastic embolization of uveal vessels had led to severe uveitis. Foci of metastasis were also in the heart, kidney, and cerebral meninges.