A case of lipogranulomatous conjunctivitis in a horse.

OBJECTIVE: To describe a case of lipogranulomatous conjunctivitis in a horse. ANIMAL STUDIED: A client-owned 12-year-old Standardbred gelding presenting with chronic conjunctivitis and palpebral masses. METHODS: Complete ophthalmic examination, surgical excision, histopathology, and bacterial culture of biopsy samples were performed. RESULTS: Upper and lower eyelids of both eyes were affected, with multiple yellow-to-white nodules on the palpebral conjunctiva, adjacent to the eyelid margin. Nodule removal was achieved via partial tarsal plate excision. Histopathological examination revealed granulomatous inflammation and large droplets of presumed free lipid in the conjunctival lamina propria. The animal was diagnosed with lipogranulomatous conjunctivitis. No postoperative ocular discomfort was observed for months; however, 3 years later, new conjunctival nodules were noticed, requiring a second surgical procedure on three of the eyelids. Transient entropion in the left lower eyelid was observed 2 months after the second surgery, and no recurrence of conjunctival nodules was observed after 18 months of follow-up. CONCLUSION: To our knowledge, this is the first report of lipogranulomatous conjunctivitis in horses.

Epidemiology and clinical significance of canine distichiasis: A retrospective study of 291 cases.

OBJECTIVE: To describe the epidemiological factors and clinical significance of canine distichiasis. ANIMALS STUDIED: Two hundred and ninety-one client-owned dogs. METHODS: Retrospective study of medical records for canine patients diagnosed with distichiasis between 2010 and 2019 in an ophthalmology specialty practice. The breed, sex, skull conformation, coat type, age at the time of diagnosis, reason for presentation, clinical examination findings, and affected eyelid(s) were reviewed. RESULTS: The prevalence of distichiasis was 5.5% (95% confidence interval (CI): 4.9-6.1) in the population of dogs presented to an ophthalmology specialty practice. The breeds with the highest prevalence were English bulldogs (35.2%, 95% CI: 26.7-43.7) and American cocker spaniels (19.4%, 95% CI: 8.3-30.5). The prevalence was significantly higher in brachycephalic dogs (11.9%, 95% CI: 9.8-14.0) than in non-brachycephalic dogs (4.6%, 95% CI: 4.0-5.3) and in short-haired dogs (8.2%, 95% CI: 6.8-9.6) than in dogs with other coat types (5.3%, 95% CI: 4.5-6.1). Most dogs were affected bilaterally (63.6%, 95% CI: 58.0-69.1). Among dogs with clinical signs, 39.0% (95% CI: 26.5-51.4) exhibited corneal ulceration, including superficial ulcers (28.8%, 95% CI: 17.3-40.4) and deep stromal ulcers (10.2%, 95% CI: 2.5-17.8). Distichiasis was non-irritating in 85.0% (95% CI: 80.6-89.4) of affected dogs. CONCLUSION: This study reports the largest cohort of canine distichiasis to date. In a large proportion of dogs, distichiasis was a non-irritating condition. However, brachycephalic breeds, especially English bulldogs, were the most frequently and severely affected.

Outcome of medical therapy for keratomalacia in dogs.

OBJECTIVES: To evaluate the clinical and visual outcomes following intensive medical therapy for keratomalacia in dogs. MATERIALS AND METHODS: Medical records were screened to identify dogs with corneal ulcers and keratomalacia. All patients were given the same topical treatment protocol with frequent administrations of tobramycin in combination with equine serum. Surgical treatment during the first 15 days of follow-up was considered as medical treatment failure. RESULTS: We report on 57 ulcers with keratomalacia from 53 dogs. Medical treatment was successful in 31 of 57 ulcers with a median healing time of 5 days (range 2 to 15 days). At 60 days after epithelialisation, 14/15 medically-treated eyes were visual. In one case, corneal perforation was observed 1 month after healing and required surgical stabilisation. CLINICAL SIGNIFICANCE: Intensive medical therapy has the potential to achieve healing of some ulcers with keratomalacia. Surgical stabilisation in response to progression of stromal loss was required in less than half of the cases.

Conjunctival bacterial and fungal flora and cutaneous fungal flora in healthy domestic rabbits (Oryctolagus cuniculus).

OBJECTIVES: To determine the normal conjunctival bacterial and fungal flora in healthy rabbits, to compare the fungal flora from the conjunctival sac with periocular cutaneous fungal flora and to evaluate potential changes in type of micro-organisms over time. MATERIALS AND METHODS: Samples from 50 pet rabbits with a normal ophthalmic examination were obtained from conjunctival sacs using sterile cotton swabs and from the interpupillary skin space using a piece of sterile carpet. Samples were collected twice, 4 weeks apart, and cultured to evaluate bacterial and fungal populations. RESULTS: Bacteria were recovered from 35.9% of conjunctival swabs. Corynebacterium species (32.4%), Staphylococcus species (18.3%), Pasteurella species (9.9%) and Moraxella species (8.5%) were the most frequently isolated organisms. Fungi were recovered from 14.6% of conjunctival swabs. The most common fungal genera were Aspergillus (37%), Scopulariopsis (14.8%) and Penicillium (11.1%). Fungal cultures from periocular integument yielded positive results in 96.3% of samples; the same fungal organism was isolated in both conjunctival and cutaneous culture in nine of 20 rabbits (45%). When comparing results 4 weeks apart in 32 of 50 animals, only three rabbits with a positive bacterial culture and one rabbit with a positive fungal culture had the same result at the subsequent test. CLINICAL SIGNIFICANCE: Fungi and bacteria isolated from the conjunctival sac of rabbits may represent transient seeding from the environment. To our knowledge, this is the first report of fungal composition of the conjunctival sac of rabbits and evaluation of the potential transient nature of both bacterial and fungal composition of this conjunctival flora.

Lateral orbitotomy for treatment of an orbital abscess in a dog.

A two-year-old Jack Russell terrier was diagnosed with a retrobulbar abscess and orbital cellulitis. The diagnosis was confirmed by ultrasound, magnetic resonance imaging examination and ultrasound-guided fine-needle aspiration. Transoral ventral drainage was attempted but was unsuccessful. The abscess was successfully treated by open drainage through a lateral orbitotomy. Despite the exposure of the orbital structures, the orbital soft tissues healed by second intention without further complications. The open drainage was well tolerated and resulted in immediate reduction of inflammation and pain, allowing a quick recovery. This report describes the diagnosis and, surgical management and the long-term (3 years) follow-up of an unusual case of orbital abscess associated with diffuse periorbital cellulitis successfully treated by open drainage through a lateral orbitotomy.

Endogenous endophthalmitis caused by Enterococcus faecalis in a cat.

A three-year-old male neutered domestic shorthair cat was presented for loss of vision associated with hyperthermia, lethargy and anorexia. Ophthalmic examination revealed a bilateral panuveitis. Cytological examination of aqueous and vitreous humours was performed and revealed a suppurative inflammation associated with numerous cocci. Enterococcus faecalis was identified by bacterial culture from aqueous and vitreous humour. No primary infection site was identified. Active uveitis resolved after systemic antibiotic therapy, but the vision loss was permanent. To the authors' knowledge, this is the first reported case of endogenous bacterial endophthalmitis secondary to E. faecalis infection in a cat.

Retrospective study of 155 cases of prolapse of the nictitating membrane gland in dogs.

A retrospective study of 155 cases (114 dogs). The breed, sex and age at the time of the first and opposite onset of nictitans gland prolapse were recorded. Long-term follow-up with a minimum of one-year duration was performed by telephone conversations. One hundred and fourteen dogs representing 155 nictitans gland prolapses were included. 75.4 per cent of the first prolapse occur before one year of age. Unilateral nictitans gland prolapse was observed in 64 per cent of cases. When the condition was bilateral, it occurred simultaneously in 41.4 per cent. When it was bilateral but not simultaneous (24/41), the opposite gland prolapse occurred within three months in 70.8 per cent of the cases. Five breeds were most commonly affected by the bilateral condition: French bulldog, shar pei, great dane, English bulldog and cane corso.

Non-viral gene therapy for GDNF production in RCS rat: the crucial role of the plasmid dose.

Glial cell line-derived neurotrophic factor (GDNF) is one of the candidate molecules among neurotrophic factors proposed for a potential treatment of retinitis pigmentosa (RP). It must be administered repeatedly or through sustained releasing systems to exert prolonged neuroprotective effects. In the dystrophic Royal College of Surgeon's (RCS) rat model of RP, we found that endogenous GDNF levels dropped during retinal degeneration time course, opening a therapeutic window for GDNF supplementation. We showed that after a single electrotransfer of 30 µg of GDNF-encoding plasmid in the rat ciliary muscle, GDNF was produced for at least 7 months. Morphometric, electroretinographic and optokinetic analyses highlighted that this continuous release of GDNF delayed photoreceptors (PRs) as well as retinal functions loss until at least 70 days of age in RCS rats. Unexpectedly, increasing the GDNF secretion level accelerated PR degeneration and the loss of electrophysiological responses. This is the first report: (i) demonstrating the efficacy of GDNF delivery through non-viral gene therapy in RP; (ii) establishing the efficacy of intravitreal administration of GDNF in RP associated with a mutation in the retinal pigment epithelium; and (iii) warning against potential toxic effects of GDNF within the eye/retina.

Primary lens instability in ten related cats: clinical and genetic considerations.

OBJECTIVES: To describe bilateral lens instability in 10 related domestic shorthair cats over three generations. METHODS: Complete ophthalmic examinations were performed. Lentectomies were carried out. Sections of affected lenses focused on the equatorial area were examined by transmission electron microscopy. The potential involvement of several candidate genes (ADAMTS17, ADAMTSL4, ADAMTS10 and FBN1) known to be associated with lens luxation in other species was investigated. RESULTS: The group of animals included 10 related cats, nine of them being affected by lens instability over three generations. Transmission electron microscopy showed the presence of zonular material at the lens equator. Signs of lens instability were not associated with other ocular disease. Analysis of the pedigree suggests a dominantly inherited condition. A mutation in ADAMTS17 was excluded, but a possible association between the condition and a microsatellite flanking FBN1 indicates this gene should be considered a strong candidate responsible for primary lens luxation in this pedigree. CLINICAL SIGNIFICANCE: These observations suggest an inherent zonular defect unrelated to extraneous factors. The family relationship is compatible with a possible genetic basis, and the pedigree suggests that the condition could be dominant. Data also suggest the mutation in the FBN1 gene could be responsible for primary lens luxation in this pedigree of cats.

A case of conjunctival melanoma in a cat.

Since 1985, 5 cases of feline conjunctival melanoma have been reported in the literature. Information on feline conjunctival melanoma epidemiological features, localizations, macroscopic features and histological features is limited. We are describing the clinical, histopathologic features and outcomes in a cat that presented clinically with a slow developing dark brown mass located under the upper eyelid of the left eye. Pertinent literature is reviewed; and the recognizable clinical features and treatment are discussed. The mass was surgically resected. Despite its size, the lesion was easily separated from underlying tissues, making possible a macroscopic complete resection that left intact the adjacent conjunctiva. The tumour histological examination has showed a pigmented melanoma lacking encapsulation, but presenting a clear zone delimiting the lesion. It was exclusively composed of epithelioid cells, and presented mild cellular anaplasia and weak mitotic activity. These features allowed it to be classified as a quite differentiated melanoma with few signs of potential malignancy. In accordance with these histologic features, no recurrence has been registered 34 months after surgery. Thus, a favorable outcome is now reported for two out of six cases of conjunctival melanoma in the cat. This report also confirms the predilection for this neoplasm to arise from the bulbar conjunctiva.

The electroretinographic phenotype of dogs with Golden Retriever muscular dystrophy.

OBJECTIVE: To characterize the flash electroretinogram (ERG) in the Golden Retriever muscular dystrophy (GRMD) dog and to compare the results with those from a control group of Golden Retrievers. To investigate whether similar abnormalities of the ERG as those found in a majority of human patients with Duchenne muscular dystrophy (DMD) are also observed in the GRMD dog, the canine model for DMD. Animals Five GRMD dogs and five age-matched clinically normal Golden Retrievers. PROCEDURE: An ophthalmic examination was carried out prior to performing electroretinography under general anesthesia. Rod, combined rod-cone and oscillatory potentials responses were recorded after dark adaptation. Responses to 30-Hz-flicker were recorded after light adaptation. The ERG responses of the GRMD dogs were compared with those of the control dogs by use of a Wilcoxon signed rank test. RESULTS: GRMD dogs had significantly reduced a and b-wave amplitudes after dim white flash stimuli (rod response) and reduced a-wave amplitude after bright white flash stimuli (rod-cone response). CONCLUSION AND CLINICAL RELEVANCE: The ERG abnormalities observed in the GRMD dog suggest a dysfunction in the rod signaling pathway. These ERG alterations are different from those observed in human patients with DMD.