Objective To describe the effects of gabapentin on ocular and behavioral parameters following oral administration in healthy cats. Materials and methods Masked, placebo‐controlled, randomized crossover‐design study. Ten young, healthy cats were scheduled for two veterinary visits 7 days apart and randomly assigned to receive a compounded capsule containing 100 mg of gabapentin or placebo (100 mg lactose powder) at the first visit and the opposite treatment at the second visit. Respiratory rate, heart rate, stress score, sedation score, compliance score, horizontal pupil diameter, intraocular pressure, and Schirmer tear test‐1 were measured prior to and 1.5, 3, and 6 h following capsule administration. Stress score, sedation score, and compliance score were assigned based on established behavioral scales. Results of the two treatments were statistically compared with a p‐value <0.05 considered significant. Results Respiratory rate was significantly reduced at 1.5 (p = 0.049) and 3 (p = 0.03) hours following gabapentin administration. Stress score was significantly reduced at 1.5 (p = 0.01) hours following gabapentin administration. Sedation score was significantly increased at 1.5 (p = 0.015) and 3 (p = 0.03) hours following gabapentin administration. Gabapentin had no significant effect on heart rate, compliance score, or ocular values measured in this study. Conclusions Gabapentin reduces stress and increases sedation at 1.5 h after treatment, with no significant effect on horizontal pupil diameter, intraocular pressure or Schirmer tear test‐1 results.

A 6‐year‐old neutered female Jack Russell terrier was investigated for sudden onset prechiasmatic bilateral blindness, left circling, reduced proprioception in the right pelvic limb and right facial allodynia. Electroretinography was normal. Magnetic resonance imaging (MRI) examination revealed that the right optic nerve and the optic chiasm were hyperintense on diffusion weighted imaging and hypointense on apparent diffusion coefficient map consistent with ischemic optic neuropathy. A concurrent lacunar infarct was detected in the left rostral colliculus. Primary systemic hypertension was diagnosed based on blood pressure measurement and no detectable abnormalities on hematology, comprehensive serum biochemistry, urinalysis including protein/creatinine and cortisol/creatinine ratios and thoracic/abdominal imaging. Prednisolone for 10 days and amlodipine long‐term were administered. Vision was not recovered after 7 months. Repeat MRI supported the diagnosis of ischemic lesions and revealed a recent striatocapsular infarct. Ischemic optic neuropathy is a well‐recognized cause of blindness in humans and should be included as a differential diagnosis for acute prechiasmatic blindness in dogs.

Objective To describe the phenotype of canine macular corneal dystrophy (MCD) including the clinical presentation, multimodal ocular imaging, histopathology, and ultrastructural analysis in ten Labrador Retrievers. Procedure Multicentered data collection. Results Labrador Retrievers affected by MCD were presented between the age of 4.5 and 6 years of age with a history of cloudy eyes and/or visual impairment. Findings on ophthalmic examination included a diffuse haze of the corneal stroma and multiple, well‐demarcated, off‐white to yellow‐brown, punctate corneal opacities heterogeneous in size. Corneal vascularization developed in most dogs as the disease progressed. Disease progression was associated with increased density of the corneal haze as well as increased number and size of the focal opacities and dogs developed significant visual impairment. Spectral domain‐optical coherence tomography revealed multifocal hyper‐reflective regions within the stroma. In vivo confocal microscopy revealed marked alterations in reflectivity throughout the entire stroma. Normal keratocytes could not be identified in affected areas. Histopathology showed stromal collagen fibers separated by acidophilic granular material on hematoxylin and eosin stain. The material stained with periodic acid‐Schiff and colloidal iron stain but not with Masson trichrome stain, confirming the accumulation of glycosaminoglycans. On electron microscopic ultrastructural examination, keratocytes presented with vacuolated rough endoplasmic reticulum and multiple electron dense cytoplasmic inclusions. In areas keratocytes appeared ruptured, with cell organelles and proteinaceous material grouped together between collagen fibers. Conclusion MCD in Labrador Retrievers has similarities with the human counterpart of the condition and is an important differential diagnosis in dogs with corneal disease.

Purpose To evaluate bacterial contamination of conjunctiva and aqueous humor in dogs undergoing phacoemulsification following asepsis with 0.5% povidone iodine and determine the influence of intravenous antibiotics on outcome of contamination. Methods Client‐owned dogs were prospectively enrolled and randomly assigned to a control group, receiving 22 mg/kg intravenous cefazolin at induction prior to sampling, or experimental group receiving no antibiotic prior to sampling, masked to the surgeon. Dogs receiving antimicrobials in the pre‐operative period were excluded. Asepsis was performed on all operated eyes using 0.5% iodine with minimum 3 min contact time at induction of anesthesia and repeated before surgery. A conjunctival swab and aqueous humor sample were collected prior to incision and following incision closure, respectively. Samples were submitted for aerobic and anaerobic bacterial culture and susceptibility. Results Seventy‐one eyes of 42 dogs were included. Median age was 9 years. Thirty‐nine and 32/71 eyes received intravenous cefazolin and no antibiotic, respectively. Median procedure time was 40 min per eye. Conjunctival cultures were positive in 6 eyes (8.5%): Serratia marcescens (5 eyes) and Cutibacterium acnes (1 eye). Aqueous humor cultures were positive in 5 eyes (7.0%): S. marcescens (2 eyes), Pseudomonas aeruginosa (2 eyes), Staphylococcus pseudointermedius (1 eye). Prevalence of positive culture did not differ between groups (p = .74), order of eyes for bilateral procedures (p = .74) and diabetic status (p = 1). Conclusions Bacterial contamination of the conjunctiva and aqueous humor was present in 8.5% and 7.0% of dogs undergoing phacoemulsification after asepsis. Lack of IV cefazolin was not significantly associated with positive culture.

Objective To report outcomes and follow‐up of Baerveldt implant surgery in dogs with primary closed‐angle glaucoma (PCAG). Materials and Methods Record review of client‐owned dogs with PCAG that underwent Baerveldt implant surgery during a 6‐year period. Postoperative intraocular pressure (IOP), vision and daily number of anti‐glaucoma drops at fixed time points (3, 12, and 24 months) were compared with preoperative values; complications were recorded. Success was defined as IOP <20 mm Hg and a positive menace response and navigation/tracking ability. Results Twenty eyes (17 dogs) were included. Mean follow‐up was 575 days (range 30–1767 days) from implant surgery to last examination. Three months postoperatively 15/20 (75%) eyes had IOP <20 mm Hg and 14/20 (70%) eyes had vision. Twelve months postoperatively 11/17 (65%) eyes had IOP <20 mm Hg and 12/19 (63%) eyes had vision. Twenty‐four months postoperatively 8/14 (57%) eyes had IOP <20 mm Hg and 7/15 (47%) eyes had vision. Denominators differ between time points as eyes were included when duration after surgery reached the relevant postoperative time point or failure was documented earlier. Within 3 months postoperatively 16/20 (80%) eyes had ≥1 complication, including transient IOP >20 mm Hg (14/20; 70% eyes), fibrin (12/20; 60% eyes), and hypotony (4/20; 20% eyes). After 3 months, postoperatively 13/16 (81%) eyes had ≥1 complication, including cataracts (13/16; 81% eyes), bleb fibrosis (3/16; 19% eyes), and conjunctival wound breakdown (1/16; 6% eyes). One patient (1 eye) was euthanized for blindness and 5/20 (25%) eyes were enucleated. Conclusions The technique was effective in controlling IOP and maintaining vision in most dogs in this study.