Publications by authors named "Andrew Lewin"

Objective: To determine the replication kinetics and cytopathic effect (CPE) of feline calicivirus (FCV) in feline corneal epithelial cells (FCEC).

Animals Studied: Seven archived FCV isolates and one archived feline herpesvirus type 1 (FHV-1) isolate, previously obtained from eight domestic short hair cats.

Procedures: FCV RNA was extracted for sequencing using Illumina MiSeq, to identify three genomically diverse isolates for further testing.

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Objective: 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).

Animals Studied: Eighteen WHCR and 16 SACR.

Procedures: 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.

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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.

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Objective: To survey the prevalence of pathogens in shelter-housed cats with active ocular surface disease (OSD).

Animals Studied: A total of 255 shelter-housed domestic cats with evidence of active OSD. No normal, unaffected cats were sampled.

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Objective: To report risk factors associated with conjunctival graft failure in dogs at four referral specialty centers.

Procedures: Records of 203 dogs (229 eyes) undergoing conjunctival graft repair of ulcerative keratitis at four hospitals from 2015 to 2021 were reviewed. Success was defined as full graft integration with globe retention at the last postoperative evaluation; vision status was reported separately.

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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.

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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.

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Background: Infectious bovine keratoconjunctivitis (IBK) is a common cause of morbidity in cattle, resulting in significant economic losses. This study aimed to characterize the bovine bacterial ocular surface microbiome (OSM) through conjunctival swab samples from Normal eyes and eyes with naturally acquired, active IBK across populations of cattle using a three-part approach, including bacterial culture, relative abundance (RA, 16 S rRNA gene sequencing), and semi-quantitative random forest modeling (real-time polymerase chain reaction (RT-PCR)).

Results: Conjunctival swab samples were obtained from eyes individually classified as Normal (n = 376) or IBK (n = 228) based on clinical signs.

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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.

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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.

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Objective: To document ocular lesions and establish ophthalmic diagnostic test reference values in a colony of African green monkeys (Chlorocebus aethiops sabaeus).

Animals Studied: Fifty one geriatric (GAGM, 19-30 years old), 10 adult (AAGM, 5-9 years old) and 10 juvenile (JAGM, <2 years old) African green monkeys housed in a single Caribbean research colony.

Procedures: Ocular biomicroscopy, indirect fundoscopy, Schirmer tear test (STT), rebound tonometry (TonoVet®) and corneal fluorescein staining were performed.

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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 ( = 28) and OSCC ( = 10) eyes of cows aged 2 to 13 years from two farms in Louisiana and Wyoming were sampled using individual sterile swabs.

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A captive-bred, adult, male, black-necked swan () was presented for evaluation of apparent vision loss due to cataract formation of an unknown duration. The animal was having difficulty navigating its enclosure, and lenticular opacities had been previously noted in both eyes. On examination, bilateral hypermature cataracts were diagnosed.

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Feline herpesvirus type 1 (FHV-1) commonly causes ocular surface disease in cats and is treated with antiviral medications targeting viral DNA polymerase (UL30/42). Herein, we describe a method to assess the FHV-1 genome for mutation development and to assess the functional impact of mutations, if present. Fourteen shelter-housed domestic cats with FHV-1 ocular surface disease were assigned to one of four treatment groups: placebo ( = 3), cidofovir 0.

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Objective: To evaluate the efficacy of 2% dorzolamide ophthalmic solution for reduction of postoperative ocular hypertension (POH) following routine phacoemulsification surgery in dogs.

Animals Studied: Thirty one dogs (53 eyes) with naturally occurring cataracts undergoing routine phacoemulsification surgery.

Procedure(s): A prospective, double-masked, randomized, placebo-controlled study design was utilized.

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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.

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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.

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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 × 10/L), anemia, and thrombocytopenia.

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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.

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Herpes simplex virus type-1 (HSV-1) ocular infection is one of the leading causes of infectious blindness in developed countries. The resultant herpetic keratitis (HK) is caused by an exacerbated reaction of the adaptive immune response that persists beyond virus clearance causing substantial damage to the cornea. Intramuscular immunization of mice with the HSV-1(VC2) live-attenuated vaccine strain has been shown to protect mice against lethal ocular challenge.

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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.

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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.

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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.

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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.

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Over 94 million domestic cats are susceptible to cancers and other common and rare diseases. Whole exome sequencing (WES) is a proven strategy to study these disease-causing variants. Presented is a 35.

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