Iris biopsy to investigate feline iris hyperpigmentation.

OBJECTIVE: To evaluate the benefit of iris biopsy in cats with iris hyperpigmentation to differentiate melanosis from early feline diffuse iris melanoma (FDIM). METHODS: The medical records of cats with unilateral iris hyperpigmentation that had undergone iris biopsy between February 2013 and September 2016 at Willows Veterinary Centre & Referral Service were reviewed. RESULTS: Seven cats with unilateral iris hyperpigmentation were included in this retrospective study. The biopsy procedure was performed under general anesthesia (n = 7) with neuromuscular blockade (n = 6) following pre-operative topical miotic therapy (n = 5). One to six biopsy samples per eye were harvested from areas of hyperpigmentation. The samples were partial thickness (n = 4 eyes) and full thickness (n = 3 eyes). Complications were minor: mild intra-operative hemorrhage (n = 4), fibrin clot (n = 2), corneal ulcer (n = 1), post-operative ocular hypertension (n = 1), dyscoria (n = 1), and pseudopolycoria (n = 2). The first biopsy was diagnostic in six cats; a repeat biopsy was necessary in one cat. Histopathology was consistent with melanosis in five cats and with early FDIM in two cats. Screening for signs of metastatic disease (thoracic computed tomography and abdominal ultrasonography) was negative in the two cats with a preliminary diagnosis of early FDIM. Subsequent enucleation and histopathology confirmed the initial diagnosis in both cases. CONCLUSIONS: Iris biopsy in cats with iris hyperpigmentation can be beneficial to differentiate melanosis from early FDIM and thereby help to justify the decision for early enucleation.

Parotid duct transposition in dogs: a retrospective review of 92 eyes from 1999 to 2009.

OBJECTIVE: The aim of this study was to perform a retrospective review of parotid duct transposition (PDT) in the dog to determine the rate and nature of complications, the success and failure rates and to evaluate owner satisfaction. METHODS: Medical records of 56 dogs (92 eyes) that underwent PDT and subsequent follow-up by a veterinary ophthalmologist were reviewed. Forty owners (40 dogs/66 eyes) were contacted by telephone and 37 owners (37 dogs/60 eyes) also completed a visual analog scale questionnaire. Statistical evaluation included Wilcoxon Signed Rank tests, one-way analysis of variance and Kaplan-Meier survival analysis with Wilcoxon and Log-rank tests. RESULTS: The mean follow-up was 38.7 months (range 1-109 months). The surgical success rate was 92% (85/92 eyes). Total failures (8%, 7/92 eyes) were because of severe saliva intolerance (n = 5 eyes) and PDT failure (n = 2 eyes). The complication rate was 50% (46/92 eyes) of which 61% (28/46 eyes) were managed medically and 39% (18/46 eyes) required further surgery. Ninety percent (36/40) of owners indicated that they would proceed with surgery again. Statistically significant improvements in owner perception of ocular comfort, number of daily topical treatments, ocular wetness, and postoperative vision were identified. CONCLUSIONS: This study shows that PDT is a successful procedure based on clinical findings and in terms of owner perception. It has also demonstrated that PDT improves ocular comfort and vision in medically refractive cases of keratoconjunctivitis sicca, and that a low level of on-going management is required in 33% of cases.