Search

An adult silver arowana ( Osteoglossum bicirrhosum) presented with a 2-month history of acute onset ventral strabismus of the right eye associated with a cystic structure overlying the dorsal aspect of the globe. Aspiration of the cyst, removal of redundant conjunctival tissue, and apposition of the surgical edges of the conjunctiva did not correct the strabismus. Magnetic resonance imaging of the head and histopathology of the eye did not reveal significant differences between affected and unaffected eyes except for a more posterior dorsal rectus muscle insertion site in the affected eye. This case report documents and describes a syndrome well known among arowana hobbyists as 'drop eye'. [ABSTRACT FROM AUTHOR]

Objective To describe five cases of protozoal keratitis or conjunctivitis in dogs with chronic preexisting ocular surface disease treated with long-term immunosuppression. Animals studied Five dogs that developed corneal or conjunctival mass lesions. Procedures The database of the Comparative Ocular Pathology Laboratory of Wisconsin was searched for canine cases diagnosed with corneal or conjunctival protozoal infection. Five cases were identified, and tissues were examined using routine and special histochemical stains: immunohistochemical labels for Neospora caninum, Toxoplasma gondii, and Leishmania spp., and tissue sample PCR for Leishmania spp. , Trypanosoma cruzi, tissue coccidia (i.e., T. gondii/Sarcocystis/Neospora), piroplasms, trichomonads, and Acanthamoeba. Electron microscopy was performed for two cases, and serology for N. caninum and T. gondii was available for three cases. Results Preexisting ocular diseases included keratoconjunctivitis sicca and pigmentary keratitis ( n = 4) and pyogranulomatous meibomian adenitis ( n = 1). All dogs were treated with tacrolimus or cyclosporine for at least 1.2 years. Dogs were presented with fleshy corneal or conjunctival masses that were clinically suspected to be neoplastic ( n = 4) or immune mediated ( n = 1). Histologic examination revealed granulomatous inflammation with intralesional protozoal organisms. Amoeba ( n = 2), T. gondii ( n = 2), or Leishmania mexicana ( n = 1) were identified using molecular techniques. Serological tests were negative. Conclusions Protozoal keratitis and conjunctivitis without systemic involvement appears rare and may be associated with chronic preexisting ocular surface disease treated with long-term immunosuppression. Based upon clinical appearance, lesions could be confused with neoplasia. This is the first report of amoebic keratoconjunctivitis in dogs and of L. mexicana in dogs in the United States. [ABSTRACT FROM AUTHOR]

A captive female square-lipped rhinoceros born in 1993 had been showing intermittent signs of bilateral conjunctivitis and conjunctival proliferation since 1998. Periodic improvement was noted, especially in winter, but overall the condition had deteriorated over the years. Treatment with various topical, intralesional, and systemic antibiotics and glucocorticosteroids was largely ineffective, as were repeated dewormings. No primary cause for these lesions was found in biopsies taken in 2000 and 2006, although a severe infiltrate of numerous eosinophils was observed in the latter. As the condition worsened, secondary corneal changes were noted, and eventually vision was lost due to proliferative conjunctival tissue. Aggressive resection of the proliferating tissue in 2013 restored vision and submitted biopsies yielded a diagnosis of severe allergic conjunctivitis, eosinophilic granuloma, and habronematid ( Habronema or Draschia) larval infection. As no other rhinoceros in the herd was affected, including two calves born to the patient who were in close contact with their mother, it was concluded the presentation was most likely due to a hypersensitivity reaction to the dead or dying larvae. Fly repellent is now regularly applied around the eye of this rhinoceros, and a protective face mask has been fitted. Ongoing periodic relapses are treated with oral ivermectin, topical antibiotics, and steroids. [ABSTRACT FROM AUTHOR]

Purpose To describe clinical and pathological features of canine orbital rhabdomyosarcoma ( COR). Methods Retrospective review of patients with COR from the archives of the Comparative Ocular Pathology Laboratory of Wisconsin and the University of Wisconsin Veterinary Medical Teaching Hospital (1983-2014). Results Eighteen cases of COR were identified, all diagnosed in an 8-year period (2006-2014). Affected dogs were typically young (range 1-8; median 2 years), and both sexes were equally represented. Common clinical signs included exophthalmos (16/18) with dorsolateral deviation of the globe (10/18) and elevation of the nictitans (12/18). Ultrasonography, performed in nine cases, revealed an orbital mass with mixed echogenicity and posterior globe indentation. Advanced imaging, performed in nine cases, demonstrated a soft tissue mass with variable contrast enhancement and lysis of the orbital bones (5/9). Histologically, all tumors were subclassified as embryonal rhabdomyosarcoma. All neoplasms demonstrated positive immunohistochemical labeling for desmin, and 14/18 were positive for skeletal muscle actin. Follow-up information was available for 15/18 cases. Older dogs, aged 6-8 years, had no clinical signs of recurrence or metastasis 8-13 months postdiagnosis (4/4). Most younger dogs (9/11), aged 1-4 years, were euthanized within 6 months (median 2.5 months) of diagnosis due to recurrence at the surgical site (5/9) and/or metastasis (5/9). Conclusions Canine orbital rhabdomyosarcoma is a highly malignant neoplasm in juvenile dogs, but may be amenable to surgical resection in older dogs. This duality in biologic behavior may reflect differences in tissue of origin between juvenile onset tumors and adult onset tumors. [ABSTRACT FROM AUTHOR]

Purpose To describe the various types of primary neoplasms affecting the third eyelid ( TEL) gland of dogs and cats. Methods A retrospective search of the Comparative Ocular Pathology Laboratory of Wisconsin ( COPLOW) database was performed. Veterinary ophthalmologists, primary care veterinarians, and, when appropriate, owners were contacted for patient follow-up information. Patient data points collected included species, age, sex, breed, laterality, tumor type, surgical margins, recurrence, metastasis, and length of follow-up. Results A total of 127 canine and 18 feline cases met the inclusion criteria. The most common canine TEL gland tumor was adenocarcinoma ( n = 108; 85.0%) followed by adenoma ( n = 18; 14.2%) and squamous cell carcinoma ( SCC) ( n = 1; 0.8%). For canine cases with follow-up information available ( n = 62), 8.1% had confirmed or suspected metastasis and 11.3% had confirmed or suspected local recurrence of disease. The most common feline TEL gland tumor was adenocarcinoma ( n = 15; 83.3%) followed by SCC ( n = 3; 16.7%). For feline cases with follow-up information available ( n = 9), 40.0% had confirmed or suspected metastasis and 30.0% had confirmed or suspected local recurrence of disease. Conclusions This study determined that adenocarcinoma was the most common third eyelid gland tumor in both dogs and cats. The overall survival times were less, and metastatic occurrence and recurrence rates appeared to be higher for feline tumors as compared to those diagnosed in dogs. This is the first report of SCC originating from glandular ductular epithelium. [ABSTRACT FROM AUTHOR]

Objective To describe clinical, in vivo confocal microscopic, histopathologic, polymerase chain reaction assay for antigen receptor rearrangement ( PARR) and immunohistochemical features of a horse with suspected malignant transformation of corneal B lymphocytes in immune-mediated keratitis ( IMMK) and to also report surgical management and adjunctive treatment including topical and radiation therapies. Case description A 15-year-old Oldenburg gelding was examined for presumptive progressive stromal IMMK of the right eye which became refractory to medical management. Corneal in vivo confocal microscopy revealed a marked infiltration of neovascularization, leukocytes, and dendritic cells. Superficial keratectomy was performed. Histopathologic and immunohistopathologic abnormalities of the cornea were restricted to the anterior and mid-stroma and included sheets of medium-size atypical lymphocytes which stained positively for CD79a and CD20 and also demonstrated clonal rearrangements of immunoglobulin heavy chain 2 ( IGH2) and 3 ( IGH3) confirming B-cell lymphoma. Complete physical examination, complete blood count, serum chemistry, thoracic radiographs, and thoracic ultrasound were performed. No evidence of systemic metastasis was found. Adjunctive local therapy included topical dexamethasone, mitomycin C, and radiation therapy using electronic surface brachytherapy. Follow-up at 16 months revealed a lack of corneal infiltrate and progressive clearing of corneal fibrosis and superficial pigment. Conclusions This case represents a unique presentation of primary corneal lymphoma in the horse. Tumor development was associated with chronic IMMK and chronic topical anti-inflammatory therapy. Surgical excision with adjunctive therapy using mitomycin C and electronic surface brachytherapy was well tolerated and considered curative. Future immunohistochemistry and PARR will be important in characterizing the IMMK syndrome and its variations. [ABSTRACT FROM AUTHOR]

Objective To quantify the total number and luminal areas of the short posterior ciliary arteries ( SPCA) surrounding the canine optic nerve at the level of the sclera/lamina cribrosa in normal dogs and compare this data to dogs with a history of acute (≤7 days) glaucoma. Procedures Twelve normal globes were obtained through Harlan Laboratories, the UW-Madison School of Veterinary Medicine necropsy service and via enucleation submissions to the Comparative Ocular Pathology Laboratory of Wisconsin ( COPLOW). Ten globes with a history of acute glaucoma were obtained from submissions to the COPLOW. Optic nerves were cross-sectioned in 20 micron steps, and five distinct levels were identified: the retinal nerve fiber layer; the retinal pigmented epithelium and neural canal opening; the choroid/pre-lamina; the sclera/lamina cribrosa; and the retro-lamina. At the level of the sclera/lamina cribrosa, SPCA profiles were counted and the luminal area was measured using Cell Sens software. Normal and glaucomatous globes were compared using ANOVA. Results Statistically significant smaller luminal areas and fewer numbers of arteries were recorded between normal and glaucomatous globes. Conclusions The glaucomatous eyes in this study have SPCA with decreased lumina, suggestive of a vascular pathology present at the early stages of clinical glaucoma. Smaller lumina may be a contributing factor to the ischemia, necrosis, and the eventual full-thickness retinal atrophy often seen in glaucomatous dogs. [ABSTRACT FROM AUTHOR]