We believe drug-induced anhidrosis is the likely cause of hyperthermia in some foals treated with erythromycin.

OBJECTIVE To evaluate effects of topical ophthalmic administration of diclofenac on intraocular pressure (IOP) when applied at 4 frequencies to eyes of Beagles. ANIMALS 8 ophthalmologically normal Beagles. PROCEDURES The study involved four 5-day experimental periods each separated by a 16-day washout period. During each period, 1 drop of 0.1% diclofenac sodium ophthalmic solution was administered to the right eye at 4 treatment frequencies (1, 2, 3, or 4 times/d); 1 drop of eyewash was administered to the left eye as a control treatment. A complete ophthalmic examination was performed on days 0 (day before first treatment) and 5 of each experimental period. Gonioscopy was performed on day 0 of the first period. The IOPs were measured at 7 am and 7 pm on days 1 through 5. RESULTS No abnormalities were detected during neuro-ophthalmic and ophthalmic examinations on day 0 of each experimental period. No adverse reactions to administration of diclofenac or eyewash were observed at any time point. No abnormalities were detected during ophthalmic examinations performed on day 5, and IOPs remained < 25 mm Hg in all 4 periods. No significant differences were identified between the treated and control eyes or among the 4 treatment frequencies. CONCLUSIONS AND CLINICAL RELEVANCE Topical ophthalmic administration of diclofenac up to 4 times/d in dogs with no ophthalmic abnormalities did not significantly increase the IOP. Additional research is needed to evaluate the effect of topical ophthalmic administration of diclofenac on IOP in dogs with anterior uveitis.

Summary Lymphoma is a relatively uncommon neoplasm in the horse; however, it is considered the most common neoplasia of the equine haemolymphatic system. Limited reports of adnexal lymphoma have been documented in the literature, with no known reports of recurrence nearly a decade after mass excision. The objective is to describe a case of recurrent adnexal lymphoma in a 20‐year‐old Quarter Horse gelding presented to the Ophthalmology service at the University of Florida Veterinary Hospital (UFVH) for evaluation of a solitary subconjunctival mass of the right eye (OD). A focal, pink, fleshy mass associated with the dorsomedial bulbar conjunctiva was noted. An excisional biopsy was performed. Histopathology revealed lymphoma with clean margins. The client declined staging and further therapy at the initial visit. Approximately 8 years later, the horse began to exhibit intermittent mild to moderate diffuse swelling of the conjunctiva OD. Six months after onset, the swelling worsened acutely and was accompanied by severe swelling of the left conjunctiva (OS). The horse then returned to UFVH and was diagnosed with diffuse, bilateral conjunctival lymphoma. Humane euthanasia was elected. T cell lymphoma was confirmed with immunohistochemistry performed post‐mortem. At necropsy, neoplastic tissue was observed throughout the adnexal and ocular tissues of both eyes and in the submandibular lymph nodes. Adnexal lymphoma is an uncommon neoplasm in the horse. To the authors’ knowledge, this is the first documentation of a nodular adnexal lymphoma that involved an 8‐year period without recurrence followed by development of diffuse, bilateral disease. Typically, surgical excision of the nodular form of lymphoma involving the extraocular tissues yields an improved prognosis compared with the diffuse form of the disease. Further investigation is necessary to determine if nodular forms of adnexal lymphoma represent early stages of diffuse extraocular or systemic disease.

Equine ulcerative keratomycosis is relatively commonly presented to teaching hospitals in North America, with a prevalence from 24 to 86%. Horses in Colorado may have lower risk due to the dry mountain climate, but data are lacking. This study aimed to determine the prevalence of ulcerative keratomycosis amongst horses with ulcerative keratitis presented to Colorado State University Veterinary Teaching Hospital (CSU-VTH) ophthalmology service and to evaluate environmental factors (season, temperature, humidity, wind speed and elevation) associated with ulcerative keratomycosis in Colorado. A database search identified horses with ulcerative keratitis presented to the ophthalmology service at CSU-VTH from January 2002 to August 2017. Sixty-one horses met the inclusion criteria of a corneal cytology and/or culture or histopathology at the time of diagnosis; cases lacking that were excluded. Environmental factors at the boarding sites, including season, temperature, humidity, wind speed and elevation and clinical outcomes for fungal cases, were recorded. Prevalence of fungal infection amongst equine ulcerative keratitis was 16.4% (10/61), suggesting that CSU-VTH has considerably fewer ulcerative keratomycosis cases than other veterinary teaching hospitals in North America. Spring (50%, 5/10) and fall (40%, 4/10) had the highest prevalence of fungal ulcerative keratitis in Colorado. Only one case was reported in summer (10%, 1/10); no horses were positive (0%, 0/10) in winter. Only wind speed seemed to influence the development of ulcerative keratomycosis with higher wind speeds associated with greater rates of fungal involvement (P = 0.047). Other environmental factors did not show a detectable association (all P-values >0.05). Outcomes were variable. It was concluded that horses from the area of CSU-VTH appear to be at lower risk for ulcerative keratomycosis than from the areas around other North American veterinary teaching hospitals that have reported data. Most horses with keratomycosis in this area present in the spring and fall.

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