Search

Objective: To assess intraocular pressure (IOP) development in cranes and determine the impact of age, weight, species, head position, and sex. Animals Studied: Whooping cranes (WC) (Grus americana), and Mississippi‐sandhill cranes (MSC) (Grus canadensis pulla). Procedures: Chicks were manually restrained on days 1–3, 7, 21, 35, 60, 75, and 120 for routine examinations. IOP was opportunistically measured utilizing the Tonovet Plus® in D setting with the head above the heart (AH) and below the heart (BH). Values were also obtained longitudinally in adults (>120 days old) upon presentation in 1 year. Results: Intraocular pressure was highly correlated with age and weight in chicks. For every kilogram gained, IOP increased 2.46 ± 0.08 mmHg in WC and 2.66 ± 0.11 mmHg in MSC. Once hatched, IOP increased 1.13 ± 0.04 mmHg in WC and 0.87 ± 0.04 mmHg in MSC every 10 days. IOP was similar to adults at 120 days of age. In adult WC, mean IOP AH was 24.0 ± 0.4 mmHg, and BH was 27.9 ± 0.4 mmHg, there was a significant difference regarding head positioning and sex, females (25.3 ± 0.4 mm Hg) had lower IOP than males (26.5 ± 0.4 mmHg). In adult MSC, mean IOP AH was 20.7 ± 0.4 mmHg, and BH was 24.6 ± 0.4 mmHg. The difference between head positioning was significant. Conclusions: This study documents the correlation between IOP and weight or age during early development in cranes, as well as the importance of head positioning. [ABSTRACT FROM AUTHOR]

Antioxidant therapies are of interest in the prevention and management of ocular disorders such as cataracts. Although an active area of interest, topical therapy with antioxidants for the treatment of cataracts is complicated by multiple ocular anatomical barriers, product stability, and solubility. Entrapment and delivery of antioxidants with poly(lactic-co-glycolic acid) nanoparticles is a possible solution to these challenges, however, little is known regarding their effects in vitro or in vivo. Our first aim was to investigate the impact of blank and lutein loaded PLGA nanoparticles on viability and development of reactive oxygen species in lens epithelial cells in vitro. Photo-oxidative stress was induced by ultraviolet light exposure with cell viability and reactive oxygen species monitored. Next, an in vivo, selenite model was utilized to induce cataract formation in rodents. Eyes were treated topically with both free lutein and lutein loaded nanoparticles (LNP) at varying concentrations. Eyes were monitored for the development of anterior segment changes and cataract formation. The ability of nanodelivered lutein to reach the anterior segment of the eye was evaluated by liquid chromatography coupled to mass spectrometry of aqueous humor samples and liquid chromatography coupled to tandem mass spectrometry (targeted LC-MS/MS) of lenses. LNP had a minimal impact on the viability of lens epithelial cells during the short exposure timeframe (24 h) and at concentrations < 0.2 μg LNP/μl. A significant reduction in the development of reactive oxygen species was also noted. Animals treated with LNPs at an equivalent lutein concentration of 1,278 μg /mL showed the greatest reduction in cataract scores. Lutein delivery to the anterior segment was confirmed through evaluation of aqueous humor and lens sample evaluation. Topical treatment was not associated with the development of secondary keratitis or anterior uveitis when applied once daily for one week. LNPs may be an effective in the treatment of cataracts. [ABSTRACT FROM AUTHOR]

Ocular problems are often associated with traumatic injury in raptors. A comprehensive evaluation, including a complete ophthalmic examination, is vital in determining the patient's overall health and suitability for release. Steps for conducting ocular examination and diagnostic testing in raptors is discussed. Additionally, common clinical findings after trauma, as well as the mechanisms by which ocular injury occurs, are outlined. An overview of medical treatments recommended for commonly diagnosed ocular diseases and the utility of ancillary diagnostic procedures is also presented. [ABSTRACT FROM AUTHOR]

Black soldier fly (BSF) larvae have been marketed as an excellent choice for providing calcium to reptiles without the need of dusting or gut loading. However, previous studies have indicated that they have limited calcium digestibility and are deficient in fat soluble vitamins (A, D3, and E). In this feeding and digestibility trial, 24 adult male leopard geckos were fed one of three diets for 4 months: 1) whole, vitamin A gut loaded larvae; 2) needle pierced, vitamin A gut loaded larvae; or 3) whole, non-gut loaded larvae. Fecal output from the geckos was collected daily and apparent digestibility was calculated for dry matter, protein, fat, and minerals. There were no differences in digestibility coefficients among groups. Most nutrients were well digested by the leopard geckos when compared to previous studies, with the exception of calcium (digestibility co-efficient 43%), as the calcium-rich exoskeleton usually remained intact after passage through the GI tract. Biochemistry profiles revealed possible deficits occurring over time for calcium, sodium, and total protein. In regards to vitamin A digestibility, plasma and liver vitamin A concentrations were significantly higher in the supplemented groups (plasma- gut loaded groups: 33.38 ± 7.11 ng/ml, control group: 25.8 ± 6.72 ng/ml, t = 1.906, p = 0.04; liver- gut loaded groups: 28.67 ± 18.90 μg/g, control group: 14.13 ± 7.41 μg/g, t = 1.951, p = 0.03). While leopard geckos are able to digest most of the nutrients provided by BSF larvae, including those that have been gut loaded, more research needs to be performed to assess whether or not they provide adequate calcium in their non-supplemented form. [ABSTRACT FROM AUTHOR]

Objective Heat-shock proteins, particularly the 70- kDa member (Hsp70), have been implicated in facilitating wound healing in multiple tissues. Expression and localization of three HSPs were assessed in normal and wounded canine corneas to elucidate a role in epithelial healing. Methods Paraffin-embedded normal corneas, acute and repeatedly abraded corneas, and keratectomies of spontaneous chronic corneal epithelial defects ( SCCEDs) were subjected to routine immunohistochemistry for Hsp27, 47, and 70 expression. Ex vivo corneal defects were created and treated with anti- HSPs or IgG controls, and wound healing was monitored. Primary cultures of canine corneal stromal fibroblasts and corneal epithelial cells were treated with exogenous Hsp70, and an artificial wound was created in vitro to monitor restoration of the monolayer. Results Normal canine corneas exhibited constitutive expression of all HSPs evaluated. Inducible expression was demonstrated in acutely wounded tissues, and expression in the chronically abraded corneas was relocalized. All HSP expression was below the limits of detection in the epithelium of SCCED samples. Inhibition of HSPs in culture resulted in delayed wound healing when compared to controls. Hsp70-treated fibroblasts demonstrated significantly ( P < 0.001) increased migration and proliferation compared to the vehicle control; however, there was no significant effect of exogenous Hsp70 on corneal epithelial cells. Conclusions These findings suggest that HSPs are induced in the normal canine cornea during re-epithelialization. Hsp70 expression is likely important for inducing the cytoarchitectural remodeling, migration, and proliferation necessary early in the canine corneal healing response, and suppressed expression may contribute to the pathophysiology of nonhealing defects. [ABSTRACT FROM AUTHOR]

The article presents a case study of an eye infection in a cat which was diagnosed and treated at the Louisiana State University's School of Veterinary Medicine. The cat had developed soft tissue injuries in both the eyes with inflammation in left eye more pronounced. The radiography and ultrasonography was performed and retinal detachment along with granuloma was detected. Antifungal treatment was initiated. However, discontinuation of treatment by the owner resulted in relapse.

Infectious ocular surface disease (IOSD) is a common problem in shelter‐housed domestic cats and has a widespread negative impact on animal welfare. While the common etiological agents are well‐described, addressing IOSD in large groups of animals presents a management challenge to the clinician and logistical challenges to shelter employees. Treatments, diagnostics, and prevention strategies that are effective in privately owned or experimental animals may be impractical or ineffective in the shelter environment. This review article focuses on the relative prevalence of etiological agents in feline IOSD, practical diagnostic testing protocols, prevention strategies, and treatment of IOSD in shelter‐housed cats. Discrepancies between experimental laboratory‐based studies and clinical trials assessing therapeutics for treatment of feline herpes virus are highlighted. Further high‐quality clinical trials are necessary to determine optimal preventative and therapeutic protocols for IOSD in shelter‐housed cats. [ABSTRACT FROM AUTHOR]

Integrins are cell adhesion molecules important in cell–cell and cell–extracellular matrix interactions. These interactions are vital to numerous physiological processes including corneal wound healing. This review discusses the structure of integrins as well as the various roles that integrins play in the corneal wound healing process. Integrin profile abnormalities identified in various corneal pathological conditions are also reviewed. [ABSTRACT FROM AUTHOR]

Objective Animals Studied Procedures Results Conclusions To determine the replication kinetics and cytopathic effect (CPE) of feline calicivirus (FCV) in feline corneal epithelial cells (FCEC).Seven archived FCV isolates and one archived feline herpesvirus type 1 (FHV‐1) isolate, previously obtained from eight domestic short hair cats.FCV RNA was extracted for sequencing using Illumina MiSeq, to identify three genomically diverse isolates for further testing. Following reference‐based assembly, viral genomes were annotated and assessed. Superficial keratectomies were performed to isolate the corneal epithelium of cats and the cells were cultured in vitro. FCEC were infected with the three chosen FCV isolates and one FHV‐1 isolate at two different multiplicity of infection ratios (MOIs, 0.1 and 0.01 PFU/cell) and virus titration was assessed at 0, 2, 6, 12, 24, and 48 h post‐infection (hpi). Viral identity was confirmed by RT‐qPCR.Three genomically diverse FCV isolates were chosen for further assessment in the FCEC model. All infections of FCEC with FCV led to visible CPE, characterized by epithelial cell rounding and detachment from the plate by 24 hpi, while FHV‐1 led to visible CPE within 48 hpi. All three of the FCV isolates replicated effectively in FCEC at both 0.1 and 0.01 MOI, with a peak increase in titer approximately 12–24 hpi.The results support the possible role of FCV as a primary pathogen of the feline ocular surface. FCV replicates in FCEC in vitro, leading to profound CPE. [ABSTRACT FROM AUTHOR]

Objective Animals Studied Procedures Results Conclusions To establish baseline ophthalmic parameters for an endangered, semi‐wild population of healthy whooping cranes (Grus americana) (WHCR) and Mississippi sandhill cranes (Grus canadensis pulla) (SACR).Eighteen WHCR and 16 SACR.Ophthalmic examination was performed by a single observer, followed by conjunctival swab collection for aerobic bacterial culture and measurement of tear production (phenol red thread test, PRTT) and corneal diameter (CD) as tolerated. Measurement of the axial globe (AG) length, anterior chamber (AC) depth, lens thickness, vitreous chamber (VC) depth, and pecten length was performed via ocular ultrasound (OUS) as tolerated.Eyelid cicatrization (n = 1 WHCR), keratitis (n = 2 WHCR), incipient cataracts (n = 1 WHCR, n = 4 SACR), and uveal cysts (n = 1 SACR) were identified. Twenty‐one bacterial species were cultured from SACR, while 18 bacterial species were cultured from WHCR. SACR under 6 months old had increased PRTT values compared to older SACR (p = .0432). AG length and VC depth of male WHCR were greater than in female WHCR (p = .0045 and p = .0008, respectively). WHCR less than 6 months old had greater AC depth and lens thickness than WHCR over 6 months (p < .001 and p = .0013, respectively). SACR less than 6 months old had greater AC depth and lens thickness than WHCR over 6 months (p < .0001 and p < .0001, respectively).WHCR and SACR are amenable to complete ophthalmic examination. Age‐related differences in PRTT in SACR, sexual dimorphism in WHCR, and age‐related differences in AC depth and lens thickness in WHCR and SACR were identified. [ABSTRACT FROM AUTHOR]

Case Description—A great horned owl of estimated age < 1 year that was captured by wildlife rehabilitators was evaluated because of suspected cataracts. Clinical Findings—Nuclear and incomplete cortical cataracts were evident in both eyes. Ocular ultrasonography revealed no evidence of retinal detachment, and electroretinography revealed normal retinal function. Treatment and Outcome—For visual rehabilitation, cataract surgery was planned and intraocular lens design was determined on the basis of values obtained from the schematic eye, which is a mathematical model representing a normal eye for a species. Cataract surgery and intraocular lens placement were performed in both eyes. After surgery, refraction was within -0.75 diopters in the right eye and -0.25 diopters in the left eye. Visual rehabilitation was evident on the basis of improved tracking and feeding behavior, and the owl was eventually released into the wild. Clinical Relevance—In raptors with substantial visual compromise, euthanasia or placement in a teaching facility is a typical outcome because release of such a bird is unacceptable. Successful intraocular lens implantation for visual rehabilitation and successful release into the wild are achievable. [ABSTRACT FROM AUTHOR]

Objective: Feline herpesvirus 1 (FHV‐1) causes ocular surface disease in domestic cats. The purpose of this study was to assess the relationship between bacterial ocular surface microbiota and outcomes for cats with FHV‐1 ocular surface disease. Animals Studied: Twenty‐two shelter‐housed cats with confirmed FHV‐1 ocular surface disease. Procedures: Animals were grouped according to FHV‐1 shedding and ocular clinical scores following intervention: worsened outcome (WorOut, n = 11) or improved outcome (ImpOut, n = 11). Scoring and conjunctival sampling were completed on Days 1 and 8 of twice daily antiviral treatment. Bacterial DNA was extracted and submitted for 16S rRNA gene sequencing. Real‐time polymerase chain reaction was performed for selected bacterial species. Overall DNA concentration between groups was assessed. Results: Bacterial microbiota relative abundance composition was significantly different between ImpOut and WorOut groups (weighted UniFrac p =.006). Alpha diversity was significantly higher in the ImpOut group compared with the WorOut group (Shannon p =.042, Simpson's p =.022, Pielou's p =.037). Differences in the relative abundance of various phyla and species were detected between groups. Total DNA concentration was higher in the WorOut group compared with the ImpOut group (p =.04). Feline GAPDH (p =.001) and Bilophila wadsworthia (p =.024) copy number was significantly higher in the ImpOut group compared with the WorOut group. Conclusions: The results highlight the important relationship between the bacterial ocular surface microbiota and FHV‐1 infection outcomes in cats treated with antiviral medications. Low bacterial species diversity, higher overall DNA (presumed predominantly bacterial) load, and certain bacterial phyla/species were associated with poor outcomes for cats with FHV‐1 ocular disease. [ABSTRACT FROM AUTHOR]

A 22-yr-old male sulcata tortoise (Centrochelys sulcata) presented to the Veterinary Teaching Hospital at Louisiana State University for acute swelling around the eyes, lethargy, and serous oculonasal discharge. Upon physical exam, the patient had severe bilateral chemosis, was unable to open his eyes, and was dehydrated. Because of a clinical suspicion of bacterial upper respiratory infection, the patient was started on antibiotics, an anti-inflammatory, and fluid therapy. It was also hospitalized for further diagnostics and treatment. The patient was anesthetized for bloodwork, microbiological assays, diagnostic imaging, and an ophthalmic exam. During hospitalization, fluid therapy, parenteral antibiotic administration, nebulization, esophagostomy tube placement, and bilateral subpalpebral lavage system (SPLS) placement were performed. The most significant diagnostic findings were bilateral anterior uveitis and bilateral conjunctivitis. The patient was discharged 3 days following placement of the SPLS. On re-evaluation 11 days later, the patient showed marked clinical improvement and the SPLS were removed. Subpalpebral lavage systems proved to be an effective technique for treating uveitis in this animal. Without an SPLS, topical eye medications can be difficult or impossible to administer to large tortoises. [ABSTRACT FROM AUTHOR]

Normal ophthalmic parameters of the blue-tongued skink (Tiliqua scincoides), one of the largest members of the skink family of lizards, have yet to be evaluated. The objective of this study was to establish baseline ophthalmic parameters for a captive population of 12 healthy, 1-yr-old blue-tongued skinks. Ophthalmic examination, corneal touch threshold, tear production including phenol red thread test (PRTT) and modified Schirmer tear test-2 (mSTT-2), horizontal palpebral fissure length (HPFL), rebound tonometry (TONOVET and TONOVET Plus), and bacterial and fungal cultures were performed. The blue-tongued skinks were all amenable to ocular diagnostic testing. Corneal touch threshold (mean ± SD) was 5.48 ± 0.81 cm. PRTT (mean ± SD) was 9.17 ± 6.62 mm/15 sec. mSTT-2 (mean ± SD) was 2.54 ± 2.72 mm/60 sec. HPFL (mean ± SD) was 6.96 ± 0.62 mm and was positively correlated with body weight. Intraocular pressure (IOP) assessed using TONOVET (mean ± SD) was 8.43± 1.51 mmHg, whereas IOP assessed using TONOVET Plus (mean ± SD) was 12.39± 1.54 mmHg. Differences in TONOVET and TONOVET Plus tonometry values were statistically significant (P < 0.0001), and TONOVET values were positively correlated with body weight. The most common bacterial species identified were Staphylococcus xylosus (10/12) and Staphylococcus sciuri (8/12). Fungal cultures were all negative. One animal had superficial corneal ulceration that resolved with treatment. Ophthalmic examination and testing is readily performed in blue-tongued skinks. These parameters may be useful for ocular assessment of this species in a clinical setting. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of environmental temperature and relative humidity on tear test results in dogs. Animals studied: 22 normal dogs. Procedures: Routine Schirmer tear tests (STT1) and phenol red thread tests (PRTT) were administered to normal dogs in four environmental conditions with different relative humidity (RH) and temperature (T). Environmental conditions (mean ± SD) included the following: normal indoor (RH = 49 ± 4%, T = 72 ± 2°F), outdoor (RH = 62 ± 11%, T = 85 ± 6°F), indoor high humidity (RH = 85 ± 6%, T = 71 ± 1°F), and indoor low humidity (RH = 39 ± 2%, T = 76 ± 1°F). ANCOVA models were used to assess for significant associations between tear test readings and RH/T (P <.05). Results: A significant, direct positive relationship between RH and STT1 results was detected (y = 0.04909*X + 19.11, P =.006) but not between T and STT1. There was no significant relationship between PRTT and RH or T. Conclusions: These results suggest that STT1 but not PRTT is affected by RH and that T does not influence STT1 or PRTT results in normal dogs. RH is unlikely, however, to cause clinically significant effects on STT1 readings in normal dogs when performed in average indoor conditions. Future studies should investigate the influence of RH on STT1 readings obtained in dogs with keratoconjunctivitis sicca. [ABSTRACT FROM AUTHOR]

Background: Equid alphaherpesvirus 1 (EHV-1) is a global viral pathogen of domestic equids which causes reproductive, respiratory and neurological disease. Few isolates acquired from naturally infected USA-based hosts have been fully sequenced and analyzed to date. An ORF 30 (DNA polymerase) variant (A2254G) has previously been associated with neurological disease in host animals. The purpose of this study was to perform phylogenomic analysis of EHV-1 isolates acquired from USA-based hosts and compare these isolates to previously sequenced global isolates. Methods: EHV-1 was isolated from 23 naturally infected USA-based equids (6 different states, 15 disease outbreaks) with reproductive (22/23) or neurological disease (1/23). Following virus isolation, EHV-1 DNA was extracted for sequencing using Illumina MiSeq. Following reference-based assembly, whole viral genomes were annotated and assessed. Previously sequenced EHV-1 isolates (n = 114) obtained from global host equids were included in phylogenomic analyses. Results: The overall average genomic distance was 0.0828% (SE 0.004%) for the 23 newly sequenced USA isolates and 0.0705% (SE 0.003%) when all 137 isolates were included. Clade structure was predominantly based on geographic origin. Numerous nucleotide substitutions (mean [range], 179 [114–297] synonymous and 81 [38–120] non-synonymous substitutions per isolate) were identified throughout the genome of the newly sequenced USA isolates. The previously described ORF 30 A2254G substitution (associated with neurological disease) was found in only one isolate obtained from a host with non-neurological clinical signs (reproductive disease), six additional, unique, non-synonymous ORF 30 substitutions were detected in 22/23 USA isolates. Evidence of recombination was present in most (22/23) of the newly sequenced USA isolates. Conclusions: Overall, the genomes of the 23 newly sequenced EHV-1 isolates obtained from USA-based hosts were broadly similar to global isolates. The previously described ORF 30 A2254G neurological substitution was infrequently detected in the newly sequenced USA isolates, most of which were obtained from host animals with reproductive disease. Recombination was likely to be partially responsible for genomic diversity in the newly sequenced USA isolates. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to validate the use of the Reichert Tono-Vera ® Vet tonometer rabbit setting in normal ex vivo rabbit eyes and to compare the rabbit setting to the dog, cat, and horse settings of this tonometer. Procedure: Six freshly enucleated normal rabbit eyes were cannulated and connected to a fluid reservoir and physiologic monitor. Triplicate measurements were obtained with the four available settings: dog, cat, horse, and rabbit at various intraocular pressures (IOP) ranging from 5 to 80 mmHg. Bland-Altman analysis was utilized to determine bias and 95% limits of agreement for each setting. Results: Linear regression equations for the dog, horse, cat, and rabbit settings were y = 0.8101x + 2.5058, y = 0.7594x - 3.4673, y = 0.6635x + 0.3021, and y = 0.8935x + 1.3295, respectively. All settings demonstrated strong positive linear trends (dog r2 = 0.9644, horse r2 = 0.9456, cat r2 = 0.9309, and rabbit r2 = 0.9558). Bland-Altman plots revealed that the average bias and 95% limits of agreement (mmHg) were -4.73, -12.65, -12.86 and -2.73 and (-15.31, 5.86), (-29.03, 3.74), (-25.67, -0.05), and (-12.21, 6.76) for the dog, horse, cat, and rabbit settings, respectively. Conclusion: The Tono-Vera ® Vet rabbit setting provided the most accurate and precise measurements compared with the other settings, but slightly underestimated actual IOP, especially as IOP was increased. This tonometer, using the rabbit setting, is likely to be appropriate for the estimation of IOP in rabbits with the appropriate correction formula applied. [ABSTRACT FROM AUTHOR]

Simple Summary: The ocular surface microbiome is altered in certain disease states. This study aimed to characterize the ocular surface microbiome of cattle with and without ocular squamous cell carcinoma (OSCC), a common eye disease in cattle. From a sample population of ten normal adult female cattle (twenty normal eyes) and nine adult female cattle with unilateral or bilateral OSCC lesions (ten diseased eyes, eight normal eyes), significant quantitative (real-time polymerase chain reaction (RT-PCR)) and relative abundance (16S ribosomal ribonucleic acid (rRNA) gene sequencing) bacterial microbiome alterations were identified based on disease status (normal or OSCC) and geographic location. Quantitative bacterial ocular microbiome discriminant analysis (DA) was capable of accurately categorizing samples based on disease status and geographic location. Quadratic DA, a method based on relatively inexpensive and readily accessible equipment, may be valuable for differentiating between normal and OSCC-affected cattle. The ocular surface microbiome is altered in certain disease states. The aim of this study was to characterize the bovine bacterial ocular surface microbiome (BBOSM) in the context of ocular squamous cell carcinoma (OSCC). The conjunctiva of normal (n = 28) and OSCC (n = 10) eyes of cows aged 2 to 13 years from two farms in Louisiana and Wyoming were sampled using individual sterile swabs. DNA extraction followed by 16S ribosomal ribonucleic acid (rRNA) gene sequencing and real-time polymerase chain reaction (RT-PCR) were performed to, respectively, assess the relative and absolute BBOSM. Discriminant analysis (DA) was performed using RT-PCR data, and relative abundance analysis was performed using 16S rRNA gene sequencing data. The 11 most abundant phyla in both normal and OSCC-affected cows were identified using 16S rRNA gene sequencing analysis. The relative abundance of Euryarchaeota was found to be significantly lower (p = 0.0372) in OSCC eyes compared to normal eyes. Relative abundance differences within and between geographic locations were also identified. Quadratic DA categorized samples as OSCC or normal with 100% sensitivity and 83.3–100% specificity. Relative abundance analysis identified relative BBOSM phylum alterations in OSCC. Quadratic DA can be used to accurately categorize BBOSM from normal and OSCC ocular surface samples. [ABSTRACT FROM AUTHOR]

Objective: Porcine models of ocular disease are becoming increasingly utilized. A recently commercialized ocular tonometer, the Reichert Tono‐Vera® Vet, has not been evaluated for use in pigs. The purpose of this study was to calibrate this device for use in porcine eyes and to determine which settings are most appropriate for use in pigs. Procedure: The anterior chambers of five freshly enucleated normal porcine eyes were cannulated then connected to a reservoir of balanced salt solution and a physiologic monitor. Triplicate measurements were obtained with the four available settings: dog, cat, horse, and rabbit at intraocular pressures ranging from 5– to 80 mmHg. Bland–Altman analysis was utilized to determine bias and 95% limits of agreement for each setting. Results: There was a strong positive linear regression trend for all settings (dog r2 = 0.986, horse r2 = 0.947, cat r2 = 0.977, and rabbit r2 = 0.982). The linear regression equations for the dog, horse, cat, and rabbit setting were y = 1.0168x – 2.6128, y = 0.8743x – 3.4959, y = 0.9394x – 7.3188, and y = 1.1082x – 3.4077. The average bias and 95% limits of agreement for dog, horse, cat, and rabbit settings were − 2.00, −8.32, −9.58, and 0.57 mmHg, and (−7.52, 3.53), (−19.00, 2.37), (−16.66, −2.50), and (−7.79, 8.93), in mmHg. Conclusion: The Tono‐Vera® Vet dog setting was most accurate and precise setting compared to true intraocular pressures. This setting is likely to be appropriate for in vivo use in pigs, with the appropriate correction formula applied. [ABSTRACT FROM AUTHOR]

Objective: To assess the efficacy of compounded cidofovir, famciclovir, and ganciclovir for the treatment of feline herpesvirus type 1 (FHV‐1) ocular surface disease. Animals studied: 132 shelter‐housed cats qPCR positive for FHV‐1. Procedures: A masked placebo‐controlled study design was utilized. Animals were enrolled in one of four treatment groups: topical ocular placebo + oral placebo (n = 32), compounded cidofovir 0.5% ophthalmic solution + oral placebo (n = 32), compounded famciclovir oral solution (90 mg/kg) + topical ocular placebo (n = 32), and compounded ganciclovir 0.15% ophthalmic solution + oral placebo (n = 36). Cats were treated with each medication twice daily for 7 days and were evaluated on Day 1 and Day 8 using an ocular scoring system, body weight, and qPCR for FHV‐1 viral load. Results: Cidofovir significantly decreased viral load from Day 1 to Day 8 compared with placebo (p =.024). Neither famciclovir nor ganciclovir decreased viral load compared with placebo (p =.14, p =.41). There was no significant improvement of ocular scores for any drug group compared with placebo (p =.62). In all groups, 65%–75% of cats improved from Day 1 to Day 8. Juvenile cats had a significant increase in weight gain compared with placebo for cidofovir (p =.025) and ganciclovir (p =.023). All corneal ulcers in placebo animals failed to heal whereas 77% of ulcers in antiviral group animals healed. Conclusions: Topical ophthalmic cidofovir significantly decreased ocular FHV‐1 viral shedding and increased weight gain in juvenile cats. Ganciclovir increased weight gain in juvenile cats. Compounded famciclovir demonstrated limited efficacy for the treatment of FHV‐1 ocular surface disease in shelter‐housed cats. [ABSTRACT FROM AUTHOR]

A 5‐year‐old Pomeranian was diagnosed with anterior uveitis, hyphema, and secondary glaucoma OD. Concurrent retinal hemorrhage, perivascular sheathing, and papilledema were identified OS. Work‐up identified small cell lymphocytosis (>900 × 109/L), anemia, and thrombocytopenia. The patient was diagnosed with B‐cell chronic lymphocytic leukemia as a cause of the ocular findings. [ABSTRACT FROM AUTHOR]

Objective: To determine whether tropicamide, fluorescein, and proparacaine applied topically before sample collection affect the quantity or species of bacteria isolated via aerobic culture. Animals studied: 12 female adult research beagle cross‐breed dogs. Procedures: A conjunctival swab was taken before and after the sequential application of proparacaine, tropicamide, and fluorescein to the same eye (P/T/F) with a five‐minute gap between medications. Paired swabs were submitted for aerobic culture. Bacterial enumeration was performed using the spread plate method. Following a one‐week washout period, the procedure was repeated using balanced salt solution (BSS). Following a second one‐week washout period, the experiment was repeated using ofloxacin 0.3% solution. Colony counts were compared using one‐way ANOVA and Tukey post hoc comparison. Bacterial species reduction was compared using a Friedman rank test and Dunn's method. Results: The bacterial colony count for P/T/F and BSS was significantly higher than the ofloxacin group (p = 0.0052, p = 0.0022). There was no significant difference for colony counts between P/T/F and BSS (p = 0.9295). The most frequently isolated bacteria included: Psychrobacter spp., Staphylococcus spp., Corynebacterium spp., and Streptococcus spp. The bacterial species reduction for P/T/F and BSS was significantly lower than for ofloxacin (p < 0.0001, p = 0.0160). There was no significant difference for species reduction between P/T/F and BSS (p = 0.3749). Conclusions: The application of proparacaine, tropicamide, and fluorescein did not significantly decrease the amount or species of bacteria isolated from the conjunctiva in this canine population. The application of these solutions prior to ocular swab collection in healthy dogs is unlikely to affect subsequent culture results. [ABSTRACT FROM AUTHOR]

Objective: To evaluate changes in intraocular pressure (IOP) with variable head position in healthy, anesthetized horses in hoisted inversion and to assess the influence of various cofactors (age, sex, body weight, body condition score, and neck length) on IOP changes during hoisting. Animals studied: Seventeen healthy adult horses without significant ocular abnormalities. Procedures: Subjects were administered intravenous xylazine/butorphanol premedication and ketamine/midazolam induction with xylazine/ketamine boluses for anesthetic maintenance. While hoisted, IOP was measured in triplicate for each eye via rebound tonometry (TonoVet) at neutral head position (ie, eyes level with the withers), at multiple 5 cm increments above and below neutral (−20 cm through +20 cm) using foam pads for head support, and with eyes above heart level via manual support. Results: In hoisted positions, IOP ranged from 18 to 51 mmHg. Intraocular pressure significantly decreased with head position elevated ≥+15 cm from neutral and significantly increased when lowered ≤−5 cm from neutral. Neck length significantly influenced IOP (P =.0328) with linear regression indicating a median (range) increase of 0.244 (0.034‐0.425) mmHg in IOP for every 1 cm increase in neck length. Age, sex, breed, body weight, body condition score, and eye (OD vs OS) did not significantly influence IOP. Intraocular pressure only varied significantly between eyes at +10 cm above neutral (OS > OD, 1.7 ± 0.6 mm Hg, P =.0044). Conclusions: Intraocular pressure in healthy, anesthetized horses varies with head position during hoisting; increased neck length may be associated with larger changes in IOP during hoisting. [ABSTRACT FROM AUTHOR]

Objective: To determine whether wetting length of Schirmer tear test (STT) strips varies by commercial manufacturer of test. Animals Studied: Ten normal female beagle cross‐breed dogs. Procedures: Schirmer tear test strips from four commercial manufacturers were used to assess wetting lengths in‐vitro when exposed to a set volume of water over 1 minute. Digital photography was used to assess the total surface area of Schirmer strips from each manufacturer. Schirmer tear test type 1 was performed on normal dogs over 1 minute with STT strips from the same four commercial manufacturers in a randomized crossover design. ANOVA was used to detect differences between strips from different manufacturers. Results: Significant differences in wetting length were found between STT strips from different manufacturers in‐vitro (P <.0001) and in‐vivo (P <.0001). STT wetting lengths for the in‐vitro experiments (mean ± SD) were 21.2 ± 0.8 mm (Amcon Laboratories), 27.8 ± 2.7 mm (Merck Animal Health), 30.0 ± 1.7 mm (HUB pharmaceuticals), and 31.5 ± 2.3 mm (Gulden Ophthalmics). STT wetting lengths for the experiments in live dogs (mean ± SD) were 17.5 ± 3.4 mm (Amcon Laboratories), 24.8 ± 3.9 mm (Merck Animal Health), 26.5 ± 3.7 mm (HUB pharmaceuticals), and 24.0 ± 3.9 mm (Gulden Ophthalmics). The surface area of STT strips were found to vary between different manufacturers. Conclusions: Schirmer tear test type 1 results in dogs are affected by choice of STT strip commercial manufacturer. It is proposed that guidelines are created for the standardization of future STT strip production. [ABSTRACT FROM AUTHOR]

Objective: Leopard Geckos (Eublepharis macularius) are popular pets and can be affected by a range of ocular disorders. Our objective was to report ocular findings in a group of healthy captive leopard geckos and to establish reference ranges for commonly performed ocular diagnostic tests. Animals studied: Twenty-six healthy male geckos aged 1 year old (n = 4) and >2 years old (n = 22). Procedures: All animals underwent ophthalmic examination, corneal esthesiometry, modified Schirmer tear test (mSTT), rebound tonometry, conjunctival bacterial aerobic and fungal culture, and measurement of ocular dimensions. Student's t test was used to compare values of corneal esthesiometry, tonometry and mSTT between groups. Multiple correlations were assessed by Pearson correlation coefficient. Results: All animals had a normal ocular examination. Tear production as measured with a mSTT (mean ± SD) technique was 3.1 ± 1.3 mm/min and tonometry values (mean ± SD) were 8.2 ± 1.7 mm Hg. Corneal touch threshold (median, range) was 4.4 cm, 2.5-5.0. Younger animals had a significantly increased corneal sensitivity compared to older animals (P = .0383). Results of culture showed no growth for fungal organism in any animals. Conjunctival bacterial isolation rates were low, with only 7/26 samples positive for nine bacterial species. Conclusions: Leopard geckos are amenable to ophthalmic examination and ocular diagnostic database testing with minimal manual restraint. [ABSTRACT FROM AUTHOR]

Bovine herpesvirus-1 (BoHV-1) infection contributes to keratoconjunctivitis, respiratory disease, and reproductive losses in cattle. The objective of this study was to determine the most appropriate ophthalmic antiviral agent for BoHV-1 inhibition using in-vitro culture and novel ex-vivo bovine corneal modeling. Half-maximal inhibitory concentrations of BoHV-1 were determined for cidofovir, ganciclovir, idoxuridine, and trifluridine via in-vitro plaque reduction assays. In-vitro cytotoxicity was compared amongst these compounds via luciferase assays. Trifluridine and cidofovir were the most potent BoHV-1 inhibitors in vitro, while trifluridine and idoxuridine were the most cytotoxic agents. Therefore, cidofovir was the most potent non-cytotoxic agent and was employed in the ex-vivo corneal assay. Corneoscleral rings (n = 36) from fresh cadaver bovine globes were harvested and equally divided into an uninfected, untreated control group; a BoHV-1-infected, untreated group; and a BoHV-1-infected, cidofovir-treated group. Virus isolation for BoHV-1 titers was performed from corneal tissue and liquid media. Histologic measurements of corneal thickness, epithelial cell density, and tissue organization were compared between groups. Substantial BoHV-1 replication was observed in infected, untreated corneas, but BoHV-1 titer was significantly reduced in cidofovir-treated (1.69 ± 0.08 × 103 PFU/mL) versus untreated (8.25 ± 0.25 × 105 PFU/mL, p < 0.0001) tissues by day 2 of culture. No significant differences in histologic criteria were observed between groups. In conclusion, cidofovir warrants further investigation as treatment for BoHV-1 keratoconjunctivitis, with future studies needed to assess in-vivo tolerability and efficacy. [ABSTRACT FROM AUTHOR]

Canid alphaherpesvirus 1 (CHV-1) is a widespread pathogen of dogs with multiple associated clinical signs. There has been limited prior investigation into the genomics and phylogeny of this virus using whole viral genome analysis. Fifteen CHV-1 isolates were collected from animals with ocular disease based in the USA. Viral DNA was extracted for Illumina MiSeq full genome sequencing from each isolate. These data were combined with genomes of previously sequenced CHV-1 isolates obtained from hosts in the UK, Australia and Brazil. Genomic, recombinational and phylogenetic analysis were performed using multiple programs. Two isolates were separated into a clade apart from the remaining isolates and accounted for the majority of genomic distance (0.09%): one was obtained in 2019 from a USA-based host (ELAL-1) and the other in 2012 from a host in Brazil (BTU-1). ELAL-1 was found to contain variants previously reported in BTU-1 but also novel variants in the V57 gene region. Multiple non-synonymous variants were found in USA-based isolates in regions associated with antiviral resistance. Evidence of recombination was detected between ELAL-1 and BTU-1. Collectively, this represents evidence of trans-boundary transmission of a novel form of CHV-1, which highlights the importance of surveillance for this pathogen in domestic dog populations. [ABSTRACT FROM AUTHOR]