A case of malignant melanoma, a possible primary site in the digit, with systemic metastasis in a mini-Rex.

We report a case of systemic metastasis of malignant melanoma in a mini-Rex (Oryctolagus cuniculus). The animal presented with lameness of the right hind limb, swelling of popliteal lymph node, and a black mass on the first digit. Paralysis of hindlimbs and forelimbs, dysuria, and dysphagia progressed over time, and the rabbit died on day 35 from the first visit. At necropsy, many black lesions were observed in multiple organs including the marrow of most bones. Histopathologically, the tumor cells had highly atypical nuclei of various sizes and an abundant eosinophilic cytoplasm, and some cells contained melanin granules. These cells were positive for PNL2 and S-100, melanoma markers, by immunohistochemistry. This is the first report of malignant melanoma in a mini-Rex with severe malignancy and systemic metastasis including the bone marrow.

Keratometry in normal cats: a cross-sectional study in Japan using an automated handheld keratometer.

Keratometry was performed in 73 domestic cats of varied signalment in Japan using an automated handheld keratometer. The mean corneal curvature radius was significantly lower for cats younger than 1 year than for those older than 2 years (8.04 mm vs. 8.80-8.99 mm, P<0.01). The radius was significantly greater in males than in females among the cats older than 11 years (9.22 mm vs. 8.84 mm, P=0.01), while the age distributions of the males and females were similar. Corneal astigmatism did not significantly differ across the gender and age groups. The predictability of the corneal curvature and astigmatism was approximately 41-43% and less than 3%, respectively, as a function of age and bodyweight. The results highlighted some age- and sex-related keratometric variations in domestic cats in Japan.

Characterising keratometry in different dog breeds using an automatic handheld keratometer.

BACKGROUND: Keratometry is clinically important and is routinely performed as part of human ophthalmic examination. In veterinary ophthalmology, little is known about keratometry in dogs, and its practical application has been limited. The present study aimed to describe keratometry in some dog breeds popular in Japan using a handheld keratometer. METHODS: Client-owned dogs of various signalment were enrolled prospectively in the keratometry examination. Interbreed variations in mean corneal curvatures (R1R2avg) and corneal astigmatism (Δ(R1-R2)) were evaluated statistically with respect to their bodyweight based on the data which fulfilled the predetermined inclusion criteria. P<0.05 was considered statistically significant. RESULTS: On examination of 237 dogs from 16 different breeds, R1R2avg (mean±sd) ranged from 7.54±0.30 mm in Pomeranians to 9.28±0.19 mm in golden retrievers. Δ(R1-R2) (mean±sd) ranged from 0.22±0.11 mm in miniature schnauzers to 0.57±0.30 mm in French bulldogs. CONCLUSION: The present study successfully described keratometry in 16 dog breeds. The study revealed considerable interbreed variations in both R1R2avg and Δ(R1-R2), which did not necessarily correlate with bodyweight. These results are useful both clinically in fitting contact lenses in the management of corneal diseases and non-clinically in optometric studies in dogs.