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Feline herpesvirus type 1 (FHV-1) is endemic in captive cheetahs and sporadically causes devastating disease. Modified live vaccines (MLV), intended for use in domestic cats, are used in some captive cheetah populations and have been anecdotally linked to disease in certain subpopulations. Ten FHV-1 isolates from ten captive cheetahs and one isolate from an MLV used to inoculate four of the host animals were analyzed. Viral DNA was extracted for full-genome sequencing by Illumina MiSeq with viral genomes then used for phylogenomic and recombinational analyses. The FHV-1 shed by vaccinated cheetahs were almost identical to the MLV, with few variants among viral genomes. Eight cheetah FHV-1 isolates and the MLV were grouped in a clade along with FHV-1 isolates from domestic cats in the USA. The remaining two cheetah FHV-1 isolates (unknown host vaccine status) were not associated with a clade. The likely ancestral origin of these two isolates involves recombination events between Australian domestic cat and cheetah FHV-1 isolates. Collectively, these data suggest that the MLV is capable of causing clinical disease and viral shedding in some cheetahs and represents evidence of interspecies transmission of virus between domestic and wild cats.

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]

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]

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: 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]

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]

Background: Intravenous sedation is frequently necessary for ophthalmic examination in horses. Common sedation protocols have not been directly compared in terms of relative intraocular pressure (IOP) reduction, duration of IOP reduction and time to maximum IOP reduction. Objectives: To compare the effects of standing sedation protocols on IOP. Study design: Randomised cross‐over experiment. Methods: Twelve healthy horses received four intravenous sedation protocols with a 48 hours washout: 0.5 mg/kg xylazine and 0.01 mg/kg butorphanol (SED1); 10 µg/kg detomidine and 0.01 mg/kg of butorphanol (SED2); 10 µg/kg detomidine (SED3); 0.5 mg/kg xylazine (SED4). IOP was measured with rebound tonometry before sedation (Tpre) and 5, 10, 15, 30, 45 and 60 minutes post‐sedation (Tpost). Post‐sedation readings were taken with the head elevated to the Tpre position. Separately, IOP readings were also obtained following sedation with the head not elevated (TpostHeadDown). IOP values were compared using mixed ANOVA and ANCOVA models respectively with significance at P <.05. Results: All protocols decreased IOP compared with baseline with greatest reduction at Tpost5. IOP at Tpre (mean ± SD) was 21.8 ± 4.4 mm Hg. At Tpost5, IOP was 16.3 ± 3.8 mm Hg (SED1), 14.5 ± 2.9 mm Hg (SED2), 17.1 ± 3.8 mm Hg (SED3) and 16.9 ± 4.2 mm Hg (SED4). SED2 Tpost5 IOP was lower than other treatments. Considering all time points following sedation, SED3 IOP readings were higher than other treatments. TpostHeadDown IOPs were higher than readings taken with the head elevated (P <.001). Main limitations: Animals with ocular disease were not studied. No animals received mock sedation or equivalent. Conclusions: A combination of detomidine and butorphanol causes greater IOP reduction 5 minutes following sedation than other commonly used sedation protocols. IOP reduction is less pronounced when detomidine is used alone. Consideration of head height is important when performing IOP measurements in horses. [ABSTRACT FROM AUTHOR]

Objectives: Feline herpesvirus-1 (FHV-1) is a prevalent cause of ocular disease in cats and limited topical options for treatment currently exist. The first objective of this study was to confirm the efficacy of ganciclovir against FHV-1 in vitro. The second objective was to assess the safety and ocular tolerability of topically applied ganciclovir eye gel (GEG) in healthy cats. Methods: FHV-1 was used to infect tissue culture wells covered in maximally confluent Crandall–Rees feline kidney cells prior to the addition of three molarities of ganciclovir (8.9 µM, 17.8 µM and 89 µM) before being incubated for 48 h. Ganciclovir efficacy in vitro was then assessed using standard plaque reduction assay. Commercially available GEG (0.15%) was applied q8h to one randomly chosen eye of four healthy cats for 7 days. Commercially available lubricating eye gel (LEG) was applied to the opposite eye q8h. Complete blood counts (CBCs), blood chemistry panels (CHEM) and urinalysis (UA) were performed on all cats before and after the study period. Ocular lesions were assessed daily using a standardized scheme. Results: Ganciclovir led to a significant reduction in FHV-1 plaque number, area and diameter at all tested molarities in vitro. The highest molarity assessed (89 µM) caused a 100% reduction in viral plaque number. There was no significant difference in ocular lesion scores between eyes receiving GEG and LEG. Animals remained healthy throughout the study period with CBC, CHEM and UA showing no clinically significant alterations. Conclusions and relevance: Based on the in vitro results, ganciclovir appears to be effective against FHV-1 in vitro. When applied q8h as a commercial 0.15% gel to a small group of cats with normal eyes, this medication was well tolerated. Taken together, these data suggest this medication warrants further investigation in cats with ocular disease caused by FHV-1. [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 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]