Ophthalmic Parameters and Ophthalmoscopy of Burrowing Owls (Athene cunicularia).

Twelve adult burrowing owls (Athene cunicularia) maintained in a managed environment underwent complete bilateral ophthalmic examinations to assess ocular parameters and, if present, describe lesions (n = 24 eyes). Tear production was measured with a Schirmer tear test (STT), and intraocular pressure (IOP) was measured with rebound tonometry using established calibration settings (D = dog/cat, P = other species). Retinography was performed for all birds after application of topical rocuronium bromide, and corneal diameter was measured. Menace response was absent bilaterally in 7 of 12 (58.3%) owls; however, this did not appear to be related to the presence of fundic lesions. Ocular lesions were visualized in 6 of 12 (50%) owls. The most common ophthalmic abnormality noted was mild multifocal fundic pigment clumping, suggestive of chorioretinal scarring. Other ocular lesions included 1 retinal tear and 1 incipient cataract. Mean tear production was 6.1 ± 3.0 mm/min. Mean IOPs were 11.6 ± 1.8 mm Hg and 7.1 ± 1.3 mm Hg for the D and P settings, respectively, and these were significantly different (P < 0.001). The IOP results did not differ significantly based on patient age or between the right and left eyes, but a higher mean was obtained from males versus females using the D setting (P < 0.039; male mean 12.1 ± 1.9 mm Hg; female mean 10.9 ± 1.2 mm Hg). Measurements obtained from the STT were not affected by either age or sex. Corneal height was 11 mm and width was 12 mm, regardless of age or sex. The rebound tonometer D setting is recommended for measuring IOP values in this species. Burrowing owls had inconsistent mydriasis following topical rocuronium bromide application to the eye; however, a complete fundic examination was possible with or without complete mydriasis.

Bacterial isolates of indolent ulcers in 43 dogs.

PURPOSE: To determine whether bacteria are isolated from canine indolent ulcers and evaluate their influence on clinical outcomes. METHODS: Swabs for anaerobic and aerobic culture were collected from indolent ulcers of 43 client-owned dogs presenting to the University of Saskatchewan Veterinary Medical Centre. Outcomes were compared between ulcers with bacterial isolates and those without. Medical therapy was reviewed. RESULTS: Bacteria were isolated in 8/43 ulcers: Three cultured two isolates and five cultured single isolates. Staphylococcus was the most common genus isolated and was present in six ulcers: Species included unspecified [2], pseudintermedius [2], schleiferi [1], and hominis [1]. Streptococcus was the second most common isolate present in two ulcers: Species included canis and agalactiae. Tobramycin was the most common antibiotic used in ulcers with bacterial isolates prior to referral (n = 3). One case did not have conclusive follow-up data from the referring veterinarian and was therefore excluded from further analysis. All seven culture-positive ulcers were recorded as healed without complication: six healing after one procedure and one healing after two procedures. Thirty-five ulcers were culture-negative. There was no difference in outcome between indolent ulcers with bacterial isolates and those with negative cultures (P = .7475). CONCLUSIONS: Bacteria were isolated from 19% of indolent ulcers, and Staphylococcus was the most common isolate. Bacterial isolation did not influence outcome.

Risk factors for equine recurrent uveitis in a population of Appaloosa horses in western Canada.

OBJECTIVE: To characterize clinical manifestations, measure frequency, and evaluate risk factors for equine recurrent uveitis (ERU) in Appaloosa horses in western Canada. ANIMALS: 145 Appaloosa horses. PROCEDURES: Ophthalmic examinations were completed and eyes were classified as having no or mild clinical signs, or moderate, or severe damage from ERU. Clinical signs, age, sex, base coat color, and pattern were recorded. Whole blood and/or mane hair follicles were collected for DNA extraction, and all horses were tested for the leopard complex (LP) spotting pattern allele. Pedigree analysis was completed on affected and unaffected horses, and coefficients of coancestry (CC) and inbreeding (COI) were determined. RESULTS: Equine recurrent uveitis was confirmed in 20 (14%) horses. The mean age of affected horses was 12.3 years (±5.3; range 3-25). Age was a significant risk factor for ERU diagnosis (ORyear  = 1.15) and classification (ORyear  = 1.19). The fewspot coat pattern was significantly associated with increased risk for ERU compared to horses that were minimally patterned or true solids. The LP/LP genotype was at a significantly greater risk for ERU compared to lp/lp (OR = 19.4) and LP/lp (OR = 6.37). Classification of ERU was greater in the LP/LP genotype compared to LP/lp. Affected horses had an average CC of 0.066, and there was a significant difference in the distribution of CC for affected horses versus the control group (P = .021). One affected horse was the sire or grandsire of nine other affected. CONCLUSIONS: Age, coat pattern, and genetics are major risk factors for the diagnosis and classification of ERU in the Appaloosa.

Odontogenic parakeratinized cyst resulting in exophthalmos and palatine, maxillary, and zygomatic bone erosion in a dog.

A novel case of a canine odontogenic parakeratinized cyst (COPC) that resulted in exophthalmos and palatine, maxillary, and zygomatic bone erosion in a 5-year-old Chihuahua dog is reported. Final diagnosis was aided by cross-sectional imaging (magnetic resonance imaging and computed tomography) and confirmed with histologic examination of the cyst wall.

Primary bilateral corneal nerve sheath neoplasm in a dog.

A 15-year-old, neutered male, Shih Tzu cross developed progressive corneal stromal thickening and vascularization of the right eye, and 5 months later, of the left eye. Both eyes became blind due to extensive corneal opacification and were enucleated. Light microscopic examination revealed a diffuse corneal infiltrate of neoplastic mesenchymal cells, and immunohistochemistry revealed diffuse cytoplasmic vimentin immunoreactivity and variable cytoplasmic and nuclear immunoreactivity for S100 in the neoplastic cells. Transmission electron microscopy revealed desmosomes between contiguous cells, thread-like cytoplasmic processes coated with basement membrane, extracellular bundles of collagen, and axonal degeneration consistent with features of a nerve sheath neoplasm. This is the first report of primary, bilateral corneal nerve sheath sarcoma in a canine.

Effect of prolonged photoperiod on ocular tissues of domestic turkeys.

OBJECTIVE: The objective of this study is to investigate the structural and functional ocular changes that develop in turkeys exposed to a photoperiod of 23 h of light (23L) compared with a photoperiod of 14 h of light (14L). PROCEDURES: Ten-day-old Nicholas heavy strain poults were exposed to either a 14L or 23L photoperiod. Between 16 and 18 weeks of age, equal numbers of turkeys per treatment group underwent ophthalmic examination (biomicroscopy, indirect ophthalmoscopy) (n = 14), refractometry (n = 20), keratometry (n = 20), tonometry (n = 20), and full-field electroretinography (ERG) (n = 14). Postmortem analyses included orbital magnetic resonance imaging (MRI) (n = 10) and light microscopy (n = 24) at 18 weeks of age. RESULTS: Autorefraction revealed a median of -0.13 for sphere in both groups (P = 0.69), which is approximately emmetropia. The radius of curvature of the cornea was significantly higher (P = 0.0001) and the refractive power of the cornea was significantly lower (P = 0.0001) in the 23L group. The astigmatic power was significantly greater in the 23L group (P = 0.0001). Mean intraocular pressure did not differ between groups (P = 0.085). Turkeys from the 23L group had significantly larger globes in nasotemporal (P = 0.0007), dorsoventral (P = 0.015), and anterioposterior (P = 0.021) directions, and anterior chambers were more shallow (P = 0.0002). ERGs revealed the 23L group to have lower a- and b-wave amplitudes and significantly lower cone flicker amplitudes (P = 0.0008). Light microscopic examination revealed 23L turkeys to have significantly decreased numbers of nuclei in the outer nuclear layer (P = 0.0001) and inner nuclear layer (P = 0.0186), and decreased choroidal thickness (P = 0.0008). The prevalence of cataract in the 23L group was significantly higher (P = 0.001). CONCLUSIONS: Exposing turkeys to a prolonged photoperiod induces significant ocular disease.

Equine recurrent uveitis in western Canadian prairie provinces: A retrospective study (2002-2015).

The objectives of this study were to determine the demographics of horses with equine recurrent uveitis (ERU) presenting to the Western College of Veterinary Medicine and to describe and compare the prognosis of ERU in the Appaloosa with that in other breeds. Horses diagnosed with ERU by a veterinary ophthalmologist between 2002 and 2015 were included. Eye lesions were classified as mild, moderate, or severe based on clinical manifestations. Breed, age, severity, blindness, and final outcome were evaluated. Thirty-two horses fit the inclusion criteria; 62.5% were Appaloosas. Mean age at presentation was 12.13 ± 4.6 years. Equine recurrent uveitis was bilateral in 93.6% of horses and was severe in 59.4% of eyes at presentation. Bilateral blindness was present in 59.4% of horses at last follow-up. Of 27 horses available for follow-up, 63% were euthanized due to ERU. No significant differences in age, severity, blindness, or rate of euthanasia were noted between Appaloosas and other breeds. The Appaloosa is at increased risk for ERU, which is a devastating ocular disease.

Uvéite équine récurrente dans les provinces de l'Ouest canadien : étude rétrospective (2002­2015). L'objectif de cette étude consistait à déterminer les données démographiques des chevaux atteints d'uvéite équine récurrente (UER) présentés au Western College of Veterinary Medicine et de décrire et de comparer le pronostic de l'UER chez les chevaux Appaloosa avec celui des autres races. Les chevaux diagnostiqués entre 2002 et 2015 comme étant atteints de l'UER par un ophtalmologiste vétérinaire ont été inclus. Les lésions à l'œil étaient classées comme étant légères, modérées ou graves selon les manifestations cliniques. La race, l'âge, la gravité, la cécité et le résultat final ont été évalués. Trente-deux chevaux correspondaient aux critères d'inclusion : 62,5 % étaient des chevaux Appaloosa. L'âge moyen à la présentation était de 12,13 ans ± 4,6 années. L'uvéite équine récurrente était bilatérale chez 93,6 % des chevaux et était grave pour 59,4 % des yeux à la présentation. La cécité bilatérale était présente chez 59,4 % des chevaux au dernier suivi. Parmi les 27 chevaux disponibles pour le suivi, 63 % ont été euthanasiés en raison de l'UER. Aucune différence significative au niveau de l'âge, de la gravité, de la cécité ou du taux d'euthanasie n'a été signalée entre les chevaux Appaloosa et les autres races. Les chevaux Appaloosa présentent un risque accru d'UER, qui est une maladie oculaire dévastatrice.(Traduit par Isabelle Vallières).

Sudden acquired retinal degeneration syndrome in western Canada: 93 cases.

This study reviewed clinical data from dogs diagnosed with sudden acquired retinal degeneration syndrome (SARDS) in western Canada. Medical records from the Western College of Veterinary Medicine from 2002 to 2016 showed that 93 cases of SARDS were diagnosed based on presentation for sudden blindness and a bilaterally extinguished electroretinogram. The most common pure breeds were the miniature schnauzer, dachshund, and pug. The mean age at diagnosis was 8.1 years and males and females were equally affected. Most of the dogs were presented with normal non-chromatic, but abnormal chromatic pupillary light reflexes. The incidence of retinal degeneration as detected via ophthalmoscopy increased over time after SARDS diagnosis. Polyuria, polydipsia, polyphagia, weight gain, elevated liver enzyme values, isosthenuria, and proteinuria were common clinical and laboratory findings. Chromatic pupillary light reflex testing may be more valuable than non-chromatic pupillary light testing in detecting pupil response abnormalities in dogs with SARDS, although electroretinography remains the definitive diagnostic test.

Syndrome de la rétine silencieuse dans l'Ouest canadien : 93 cas. Cette étude a examiné les données cliniques provenant de chiens diagnostiqués avec le syndrome de la rétine silencieuse (syndrome de cécité soudaine acquise) dans l'Ouest canadien. Les dossiers médicaux du Western College of Veterinary Medicine de 2002 à 2016 ont montré que 93 cas du syndrome de la rétine silencieuse ont été diagnostiqués en se basant sur la présentation pour une cécité soudaine et un électrorétinogramme bilatéral sans incandescence. Les races les plus communes étaient le Schnauzer miniature, le Dachshund et le Pug. L'âge moyen au diagnostic était de 8,1 ans et les mâles et les femelles étaient également affectés. La plupart des chiens présentaient des réflexes pupillaires normaux à la lumière non chromatique mais des réflexes anormaux à la lumière chromatique. L'incidence de la dégénération rétinienne détectée par l'ophtalmoscopie a augmenté au fil du temps après le diagnostic du syndrome de la rétine silencieuse. La polyurie, la polydipsie, la polyphagie, le gain de poids, des valeurs d'enzymes hépatiques élevées, l'isosthénurie et la protéinurie étaient des résultats cliniques et de laboratoire communs. Le réflexe à la lumière pupillaire chromatique peut être plus utile que le test de la lumière pupillaire non chromatique pour détecter les anomalies de la réponse pupillaire chez les chiens atteints du syndrome de la rétine silencieuse, quoique l'électrorétinographie demeure le test diagnostique définitif.(Traduit par Isabelle Vallières).

Congenital nuclear cataracts in a Holstein dairy herd.

This report describes congenital nuclear cataracts and posterior lenticonus in a closed purebred Holstein dairy herd in Canada. Ophthalmic examinations were completed on 30 male and 249 female cattle aged newborn to 10 years old. Nutritional, infectious, and toxic etiologies were investigated. Necropsies of 3 affected calves were performed and eyes of 2 additional affected calves were examined with light microscopy. Bilateral nuclear cataracts were identified in 53/279 (19%) animals. Additional congenital anomalies observed included posterior lenticonus, iris to lens persistent pupillary membranes (n = 7), and lenticular colobomata (n = 1). Heifers did not give birth to calves with congenital nuclear cataracts (0/105), whereas the incidence of affected calves born to multiparous cows was 31% (53/171). The animals with nuclear cataracts ranged from newborn to 8 years old. The cataracts appeared to be non- or minimally progressive. Light microscopic examination of 10 affected globes confirmed nuclear cataract with posterior lenticonus (n = 10). Pedigree analysis was inconclusive. Polymerase chain reaction and sequence analysis for the NID1 gene deletion were negative. The etiology of the congenital lenticular anomalies was not determined.

Cataractes nucléaires congénitales dans un troupeau laitier Holstein. Cette étude rapporte les résultats d'une enquête sur des cataractes nucléaires congénitales et des lenticônes postérieurs dans un troupeau laitier fermé Holstein pur-sang au Canada. Des examens ophtalmiques ont été réalisés sur 30 bovins mâles et 249 bovins femelles qui étaient âgés de nouveau-né à 10 ans. Les étiologies nutritionnelles, infectieuses et toxiques ont été étudiées. Des nécropsies ont été effectuées pour trois veaux touchés et les yeux de deux veaux affectés additionnels ont été examinés à l'aide de microscopie photonique. Des cataractes nucléaires bilatérales ont été identifiées chez 53/279 (19 %) des animaux. Les anomalies congénitales additionnelles observées incluaient le lenticône postérieur, des membranes pupillaires persistantes de l'iris à la lentille (n = 7) et le colobome lenticulaire (n = 1). Les taures n'ont pas donné naissance à des veaux avec des cataractes nucléaires congénitales (0/105), tandis que l'incidence des veaux affectés nés de vaches multipares était de 31 % (53/171). Les animaux avec des cataractes nucléaires étaient âgés de nouveau-né à 8 ans. Les cataractes semblaient être non progressives ou minimalement progressives. Un examen à l'aide d'un microscope photonique de 10 globes affectés a confirmé la cataracte nucléaire avec un lenticône postérieur (n = 10). L'analyse du pedigree a été non-concluante. Une réaction d'amplification en chaîne par la polymérase et une analyse de séquence pour la suppression du gène NID1 ont été négatives. L'étiologie des anomalies lenticulaires congénitales n'a pas été déterminée.(Traduit par Isabelle Vallières).

An Aromatic Hydroxyamide Attenuates Multiresistant Staphylococcus aureus Toxin Expression.

Methicillin-resistant Staphylococcus aureus (MRSA) causes severe infections with only few effective antibiotic therapies currently available. To approach this challenge, chemical entities with a novel and resistance-free mode of action are desperately needed. Here, we introduce a new hydroxyamide compound that effectively reduces the expression of devastating toxins in various S. aureus and MRSA strains. The molecular mechanism was investigated by transcriptome analysis as well as by affinity-based protein profiling. Down-regulation of several pathogenesis associated genes suggested the inhibition of a central virulence-related pathway. Mass spectrometry-based chemical proteomics revealed putative molecular targets. Systemic treatment with the hydroxyamide showed significant reduction of abscess sizes in a MRSA mouse skin infection model. The absence of resistance development in vitro further underlines the finding that targeting virulence could lead to prolonged therapeutic options in comparison to antibiotics that directly address bacterial survival.

Blindness in a wild American black bear cub (Ursus americanus).

An approximately six-month-old wild American black bear (Ursus americanus) was found wandering in Saskatchewan and was presented to the Veterinary Medical Centre of the Western College of Veterinary Medicine for apparent blindness. Clinical examination confirmed an inability to navigate a photopic maze, bilateral tapetal hyper-reflectivity, fundi devoid of retinal vessels, and small pale optic nerve papillae. Single-flash electroretinography revealed A and B-wave amplitudes of approximately 40 and 140 microvolts, respectively, in both eyes. Histologic abnormalities included bilateral optic papillary mineralization and bilateral segmental optic nerve degeneration, with occasional intralesional lymphocytes confirmed with immunohistochemistry for CD3+. There was also bilateral multifocal retinal dysplasia, gliosis, lymphocytic retinitis, a complete lack of retinal blood vessels, an intravitreal vascular membrane, and a mild lymphocytic-plasmacytic uveitis with small pre-iridal cellular membranes. The presence of a positive ERG in a blind bear with numerous retinal ganglion cells and degenerative changes in the optic nerve are most consistent with vision loss due to optic nerve injury, which given the young age of the bear likely occurred during ocular development. The presence of ocular inflammation suggests this injury resulted from an inflammatory/infectious process. The etiology could not be determined. Hepatic concentrations of vitamin A were within the normal reference range for domestic species. Pan-herpesvirus PCR and immunohistochemistry for canine distemper virus and Toxoplasma gondii were negative, although this does not rule out these or other infectious etiologies. This represents the first case report of neonatal or congenital ocular abnormalities in an ursid species.

Golden retriever cystic uveal disease: a longitudinal study of iridociliary cysts, pigmentary uveitis, and pigmentary/cystic glaucoma over a decade in western Canada.

OBJECTIVES: To determine the incidence of iridociliary cysts, pigmentary uveitis (PU)/pigmentary cystic glaucoma (PCG) in golden retriever dogs in western Canada, the progression of iridociliary cysts to PU/PCG, and a mode of inheritance for this disorder. ANIMAL STUDIED: A total of 830 golden retriever dogs from Alberta, Saskatchewan, and Manitoba from 2004 to 2014 were studied. PROCEDURE: Data were compiled from Canine Eye Registry Foundation (CERF) or Orthopedic Foundation for Animals (OFA) records (n = 630) and clinical consultations (n = 200) for a retrospective assessment of iridociliary cysts, PU, and PCG. RESULTS: Total incidence of iridociliary cysts and PU from CERF/OFA data were 4.8% (n = 30/630) and 5.9% (n = 37/630), respectively. Incidence of PU increased with ages >4 years (12.7%, n = 32/251). Dogs diagnosed with thin-walled, attached iridociliary cysts had a high risk of being diagnosed with PU or PCG upon re-examination (56.5%, n = 13/23). No dogs diagnosed with thick-walled, anterior chamber cysts (n = 7) developed PU or PCG within the time frame of the study. Data from clinical consultations confirmed that PU carried a poor prognosis for the affected eyes as 44.9% (n = 22/49) of dogs progressed to PCG. PU- and PCG-affected dogs followed a familial pattern and there was an association with thin-walled iridociliary cysts. Pedigree analysis suggested an autosomal dominant mode of inheritance with partial penetrance. CONCLUSIONS: Thin-walled iridociliary cysts are associated with PU and PCG. All breeding golden retriever dogs should be examined annually by an ophthalmologist. The incidence of this disorder is higher in western Canada than previous reports in North America.

Primary corneal melanocytoma in a Collie.

A 6-year-old female, spayed Collie was referred to the Western College of Veterinary Medicine for a 12-month history of a progressive right corneal mass. A superficial keratectomy was performed and histopathology revealed a corneal melanocytoma with complete excision. There has been no recurrence of the neoplasm to date (12 months). This is the first known report of an isolated corneal melanocytoma in a canine.

Optic neuropathy in a herd of beef cattle in Alberta associated with consumption of moldy corn.

A group of beef cattle in eastern Alberta was investigated due to sudden onset of blindness after grazing on standing corn in mid-winter. Fumonisin-producing Fusarium spp. were isolated from the corn. Blindness was due to an optic nerve degeneration suspected to be secondary to fumonisin mycotoxin.

Neuropathie optique dans un cheptel de bovins de boucherie en Alberta associée à la consommation de maïs moisi. Un groupe de bovins de boucherie de l'est de l'Alberta a fait l'objet d'une enquête en raison de l'apparition soudaine de cécité après avoir brouté du maïs sur pied vers le milieu de l'hiver. Fusarium spp., qui produit la fumonisine, a été isolé dans le maïs. La cécité a été attribuable à la dégénération du nerf optique ayant pour cause suspectée la mycotoxine fumonisine.(Traduit par Isabelle Vallières).

Ocular Pathology.

Although not comprehensive of all ocular conditions in the equine species, this article concentrates on various ophthalmic conditions observed in the horse where laboratory diagnostics are recommended. The importance of laboratory diagnostic testing cannot be underestimated with equine ophthalmic disease. In many cases, laboratory diagnostics can aid in obtaining an early diagnosis and determining appropriate therapy, which in turn, can provide a better prognosis. In unfortunate cases where ocular disease results in a blind, painful eye necessitating enucleation, light microscopic evaluation is imperative to determine or confirm the cause of the blindness and provide a prognosis for the contralateral eye.

Chlamydia trachomatis infection prevents front-rear polarity of migrating HeLa cells.

Chlamydiae are obligate intracellular bacterial pathogens that cause trachoma, sexually transmitted diseases and respiratory infections in humans. Fragmentation of the host cell Golgi apparatus (GA) is essential for chlamydial development, whereas the consequences for host cell functions, including cell migration are not well understood. We could show that Chlamydia trachomatis-infected cells display decelerated migration and fail to repopulate monolayer scratch wounds. Furthermore, infected cells lost the ability to reorient the fragmented GA or the microtubule organization centre (MTOC) after a migratory stimulus. Silencing of golgin-84 phenocopied this defect in the absence of the infection. Interestingly, GA stabilization via knockdown of Rab6A and Rab11A improved its reorientation in infected cells and it was fully rescued after inhibition of Golgi fragmentation with WEHD-fmk. These results show that C. trachomatis infection perturbs host cell migration on multiple levels, including the alignment of GA and MTOC.

Helicobacter pylori outer membrane protein HopQ identified as a novel T4SS-associated virulence factor.

Helicobacter pylori is a bacterial pathogen that colonizes the gastric niche of ∼ 50% of the human population worldwide and is known to cause peptic ulceration and gastric cancer. Pathology of infection strongly depends on a cag pathogenicity island (cagPAI)-encoded type IV secretion system (T4SS). Here, we aimed to identify as yet unknown bacterial factors involved in cagPAI effector function and performed a large-scale screen of an H. pylori transposon mutant library using activation of the pro-inflammatory transcription factor NF-κB in human gastric epithelial cells as a measure of T4SS function. Analysis of ∼ 3000 H. pylori mutants revealed three non-cagPAI genes that affected NF-κB nuclear translocation. Of these, the outer membrane protein HopQ from H. pylori strain P12 was essential for CagA translocation and for CagA-mediated host cell responses such as formation of the hummingbird phenotype and cell scattering. Besides that, deletion of hopQ reduced T4SS-dependent activation of NF-κB, induction of MAPK signalling and secretion of interleukin 8 (IL-8) in the host cells, but did not affect motility or the quantity of bacteria attached to host cells. Hence, we identified HopQ as a non-cagPAI-encoded cofactor of T4SS function.