Publications by authors named "Richard R Dubielzig"

In collaboration with the American College of Veterinary Pathologists.

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Objective: Investigate histopathology and spectral-domain optical coherence tomography (OCT) imaging of wild owls with chorioretinitis and identify any potential correlation with an infectious etiology.

Materials And Methods: Ophthalmic examination and retinal OCT imaging were performed on fifteen great horned (Strix varia) and barred (Bubo virginianus) owls (30 eyes) with chorioretinitis and five owls with normal eyes (10 eyes). Testing to investigate the presence of potential infectious diseases included a complete blood count, biochemistry, protein electrophoresis, West Nile virus (WNV) plaque reduction neutralization test, Toxoplasma gondii modified direct agglutination test, WNV RT-PCR, and Avian Influenza RT-PCR.

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Purpose: Review octopus ocular anatomy and describe the histopathologic findings in three octopuses diagnosed with phakitis and retinitis.

Animals: Two common octopuses (Octopus vulgaris) and one giant Pacific octopus (Enteroctopus dofleini) with a history of ophthalmic disease.

Methods: A literature search was performed for the ocular anatomy section.

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We describe a case of chronic ocular trauma that resulted in fixed and free-floating, pigmented epithelial iridociliary cysts, inflammation, and secondary glaucoma in a caiman (Caiman latirostris). A 20- to 25-year-old male caiman was presented with phthisis bulbi in the right eye, and congested episcleral vessels, corneal leukoma, disorganized anterior chamber, multifocal anterior synechia, and elevated intraocular pressure in the left eye. Ocular ultrasound of the left eye revealed round structures dispersed in the anterior and posterior chambers and vitreous cavity.

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The objectives of this retrospective study were to evaluate the histopathologic changes associated with porcupine ocular quill injuries in dogs, to discuss the various methods of quill detection when quills are not grossly visible, and to discuss the pathogenesis of delayed ocular quill injuries in dogs. Seventeen globes sustaining ocular quilling injuries from 17 dogs (1986-2018) were identified in the COPLOW archives and the gross and histologic changes tabulated and compared. All cases were dogs, with one whole globe submitted from each patient.

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Purpose: To describe ocular clinical findings, gross/histopathologic findings, and treatment regimens in a series of migratory chuck-will's-widows (Antrostomus carolinensis) (CWW) with corneal epithelial defects.

Methods: Seven CWW were presented to the South Florida Wildlife Center (SFWC). Four presented with bilateral (OU) corneal ulceration; two developed corneal ulceration OU; one had no ocular lesions.

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Purpose: To investigate the relationship between phylogeny and amount of shade in a species' habitat regarding the presence or absence of an iridal granula iridica (GI) in a large sample of Artiodactyl and Perissodactyl clades and using online resources.

Methods: The Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) archives were searched for glass slide material from Artiodactyl (even-toed) and Perissodactyl (odd-toed) ungulates. The slides were examined, and the presence or absence of the GI was noted.

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The keen visual systems of birds have been relatively well-studied. The foundations of avian vision rest on their cone and rod photoreceptors. Most birds use four cone photoreceptor types for color vision, a fifth cone for achromatic tasks, and a rod for dim-light vision.

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Objective: To evaluate the clinical, histopathological, and immunohistochemical features of 17 cases of ocular surface xanthogranuloma (OSX) in dogs.

Methods: Archived records from the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) were searched for cases of canine OSX. Cases were evaluated for lipid-laden macrophages and Touton giant cells.

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This retrospective study aimed to describe and classify cats with intraocular lymphoma, determine the proportion of cases with presumed solitary ocular lymphoma (PSOL) compared with ocular manifestations of multicentric disease and assess the clinical outcomes of these patients. One hundred seventy-two cases identified through biopsy submissions were reviewed histologically; 163 of these cases were subtyped according to the WHO classification system. Cases were categorized as having PSOL or ocular lymphoma with suspected systemic involvement (SSI) based on submission forms and follow-up data.

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In a juvenile toxicology program, an unexpected finding of vacuolation of inner nuclear, ganglion cell, and nerve fiber layers of the retina was observed microscopically in routine Davidson's fixed and hematoxylin and eosin-stained tissue sections of eyes in beagle dogs at approximately 5 weeks of age. There was no necrosis or degeneration of the affected cells and no associated inflammation. Fluorescein angiography revealed no vascular leakage.

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We describe a case series of photoreceptor dysplasia with secondary retinal degeneration in juvenile Peregrine Falcons. Six Peregrine Falcons ( Falco peregrinus) and three Peregrine Falcon × Prairie Falcon ( Falco mexicanus) hybrids had early-life visual deficits. Eight birds had visual defects shortly after hatching, and one bird had visual deficits first noticed at 5 mo of age.

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Feline neovascular vitreoretinopathy (FNV) is a newly recognized rare condition affecting kittens and young domestic cats. This study investigated the clinical and pathologic findings in 22 cats with FNV. In affected cats, ophthalmoscopy of the fundus (when visible) revealed avascular peripheral retinae and epiretinal vascular membranes.

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Corneal vascular neoplasms (hemangioma and hemangiosarcoma) are rare in all species. Reported cases are single case reports in a single species. Archived cases of corneal hemangioma and hemangiosarcoma from dogs, cats, and horses were obtained from the Comparative Ocular Pathology Lab of Wisconsin (COPLOW, Madison, WI), tabulated, and examined.

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Objective: To describe the ocular anatomy of the black pacu (Colossoma macropomum), a freshwater teleost fish of the Amazon River basin, including an unusual choroid laden with adipose tissue.

Procedures: Three adult black pacu were anesthetized and examined clinically and with ocular ultrasonography, then euthanized. Three fish were euthanized and their heads imaged immediately postmortem using computed tomography.

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Objective: To present a case series of idiopathic lipoidal corneal degeneration in falcons.

Animals Studied: Five falcons including three peregrine falcons (Falco peregrinus), one prairie falcon (Falco mexicanus), and one red-naped shaheen (Falco peregrinus babylonicus) were observed to develop slowly progressive corneal opacification that began at the temporal limbus and extended centripetally across the cornea over a period of years. Four of the birds were over 20 years old.

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During the planning meeting for the Collaborative Ocular Melanoma Study (COMS) prior to the start of patient recruitment in 1986, there was an interest expressed in determining whether a relationship existed between the presence of uveal melanoma (UM) and asteroid hyalosis (AH). To answer this question, the ophthalmic examination form (unlike the pathology form for enucleated eyes) for each COMS patient asked whether AH was present or not. Though an increased prevalence was not found, this result was never published.

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Objective: To report 14 neoplasia-free feline eyes enucleated for suspected intraocular neoplasia containing only iridociliary cysts. To analyze clinical findings that may have led veterinarians to suspect neoplasia in these globes.

Procedures: The archives at the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) were searched to identify neoplasia-free feline globes enucleated for suspected neoplasia.

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Odontoameloblastoma (OA) is a mixed odontogenic tumor that is an ameloblastoma with concurrent histologic evidence of odontoma differentiation. As a mixed tumor, OA is a tripartite lesion comprised of neoplastic odontogenic epithelium, induced dental ectomesenchyme (dental pulp), and mineralized dental matrix. Although rare, OA represents a diagnostic conundrum, as it is histologically closely related to 2 other mixed odontogenic tumors: odontoma (complex and compound) and ameloblastic fibro-odontoma.

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The 'disco' clam (Finlay, 1927) is a marine bivalve that has a unique, vivid flashing display that is a result of light scattering by silica nanospheres and rapid mantle movement. The eyes of were examined to determine their visual capabilities and whether the clams can see the flashing of conspecifics. Similar to the congener , exhibits an off-response (shadow reflex) and an on-response (light reflex).

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Article Synopsis
  • A 4-year-old female Siberian husky had a history of a uveal schwannoma and showed orbital swelling 9 months after having an eye removed (enucleation).
  • A second malignant tumor appeared in the same area, indicating a recurrence of health issues.
  • The case suggests that early surgical intervention may be necessary for dogs diagnosed with uveal schwannomas to prevent further complications.
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Objective: To present a description and categorization of the histopathological lesions in avian ocular trauma.

Animal Studied: Seventy-five birds diagnosed with ocular trauma at to the Comparative Ocular Pathology Laboratory of Wisconsin.

Procedures: Histological slides were reviewed, and the type of trauma was classified by cause into either (i) blunt trauma or (ii) penetrating trauma and by duration into (i) acute or (ii) chronic.

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The lemurs of Madagascar (Primates: Lemuriformes) are a monophyletic group that has lived in isolation from other primates for about 50 million years. Lemurs have diversified into species with diverse daily activity patterns and correspondingly different visual adaptations. We assessed the arrangements of retinal cone and rod photoreceptors in six nocturnal, three cathemeral and two diurnal lemur species and quantified different parameters in six of the species.

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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.

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Purpose: We determined whether the chronic lack of optic nerve myelination and subsequent axon loss is associated with optical coherence tomography (OCT) changes in the retinal nerve fiber layer (RNFL), and whether this models what occurs in multiple sclerosis (MS) and confers its use as a surrogate marker for axon degeneration.

Methods: Using an animal model of Pelizaeus-Merzbacher disease (shp) bilateral longitudinal measurements of the peripapillary RNFL (spectral-domain OCT), electroretinograms (ERG), and visual evoked potentials (VEP) were performed in affected and control animals from 5 months to 2 years and in individual animals at single time points. Light and electron microscopy of the optic nerve and retina and histomorphometric measurements of the RNFL were compared to OCT data.

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