Jessica M. Meekins

Ophthalmic Diagnostic Tests and Ocular Findings in a Flock of Captive American Flamingos (Phoenicopterus ruber ruber)

Abstract Seventeen adult captive American flamingos (Phoenicopterus ruber ruber) (34 eyes) underwent a complete ocular examination, including assessment of menace response, pupillary light reflexes, dazzle reflex, palpebral and corneal reflexes, fluorescein staining, slit-lamp biomicroscopy, and direct ophthalmoscopy. Birds were randomly assigned to one of 2 groups for tear production and intraocular pressure measurements. Tear production was measured by modified Schirmer tear test I (n = 9 birds) or phenol red thread test (n = 8 birds), and intraocular pressure was measured indirectly by applanation (Tonopen-XL) (n = 9 birds) or rebound (TonoVet) (n = 8 birds) tonometry. Conjunctival swab samples were taken from one randomly selected eye of all 17 birds to identify surface ocular microbial flora via aerobic bacterial culture. Additionally, 3 of the 17 birds were anesthetized for bilateral B-mode ocular ultrasonography examination to obtain axial globe measurements. Results showed that the menace response and dazzle reflex were absent in all birds. Sixteen of the 17 birds were free of significant ocular disease; a small cataract and pigment on the anterior lens capsule were noted in one eye of one bird. Mean ± SD tear production was 12.3 ± 4.5 mm/min (range, 4–20 mm/min) for modified Schirmer tear test I and 24.2 ± 4.4 mm/15 s (range, 14–30 mm/15 s) for phenol red thread test. Modified Schirmer tear test I measurements were significantly lower than phenol red thread measurements (P < .001). Mean intraocular pressure was 16.1 ± 4.2 mm Hg (range, 7–22 mm Hg) for Tonopen and 9.5 ± 1.7 mm Hg (range, 7–13 mm Hg) for TonoVet. Tonopen measurements were significantly higher than TonoVet measurements (P < .001). An Enterococcus species (9/17 eyes; 53%) and a gram-positive coccus (7/17 eyes; 41%) were the bacteria most commonly isolated from conjunctival swab samples. Mean B-mode ultrasonographic globe measurements of 6 eyes (3 birds) were axial globe length, 13.8 ± 0.16 mm; anterior chamber depth, 1.75 ± 0.05 mm; lens thickness, 4.6 ± 0.06 mm; vitreous body depth, 6.95 ± 0.10 mm; and pecten dimensions, 5.1 ± 0.38 mm length, 2.2 ± 0.14 mm width. In summary, the prevalence of ocular lesions was low in this population of captive American flamingos. Results obtained from 2 types of tear and intraocular pressure measurement tests were significantly different, indicating that a single type of each diagnostic test should be consistently used. A modification of the standard Schirmer tear test or use of phenol red thread test is recommended due to the small flamingo eye.

Tear production, intraocular pressure, and conjunctival bacterial flora in a group of captive black-tailed prairie dogs (Cynomys ludovicianus).

OBJECTIVE To report ocular diagnostic test parameters and normal conjunctival bacterial flora in captive black-tailed prairie dogs. ANIMALS STUDIED Seventeen black-tailed prairie dogs, ranging in age from approximately 4-6 months to 4.5 years. Eleven males came from a zoo collection and 6 females from a wildlife rehabilitation center. PROCEDURES Complete ocular examination was performed under isoflurane anesthesia. Tear and intraocular pressure (IOP) measurements were performed on both (n = 34) eyes of 17 prairie dogs. Phenol red thread test (PRTT) was performed first, and a modified Schirmer tear test I (mSTTI) was performed 10 min later. Indirect rebound tonometry was performed using the TonoVet® . Attempts to obtain intraocular pressure measurements using an applanation tonometry instrument were unsuccessful. Conjunctival swab samples (n = 17) were taken from both eyes of each prairie dog and pooled. RESULTS The most common ocular abnormality was acquired eyelid margin defects, present in seven eyes of six prairie dogs (35.3%). Mean ± SD tear production was 13.6 ± 7.8 mm/15 s (range, 3-30) for PRTT and 1.2 ± 0.9 mm/min (range, 0-4) for mSTTI. Mean ± SD IOP was 7.7 ± 2.2 mmHg (range, 3-11.4). A Staphylococcus xylosus (7/17; 41.2%) organism and a hemolytic Staphylococcus species (5/17; 29.4%) were most commonly isolated from the prairie dog conjunctival sac. CONCLUSIONS There was a moderate prevalence of acquired peri-ocular lesions in this group of captive black-tailed prairie dogs. While widely variable, results of tear test and intraocular pressure measurements are reported. Staphylococcus was the most commonly isolated bacterial genus.

Evaluation of conjunctival bacterial flora in a herd of goats in the Midwestern United States

OBJECTIVE To identify conjunctival bacterial flora in healthy adult and newborn kid goats in the Midwestern United States and to compare vaginal and ocular surface flora in dam-kid pairs. ANIMALS STUDIED Thirty mixed-breed (crosses between Boer, Kiko, and Syfan Spanish) goats, 20 adult does and 10 newborn kids. PROCEDURES One eye of 15 adult goats (n = 15 eyes) and 5 kids (n = 5 eyes) was randomly selected. A subset of 5 adults (n = 10 eyes) and 5 kids (n = 10 eyes) underwent bilateral sampling. Each recently kidded dams vaginal canal (n = 10) was also sampled. Two swabs were collected from each sample site for aerobic bacterial culture and Mycoplasma and Chlamydia spp. PCR. RESULTS Of the animals with positive cultures, Staphylococcus and Streptococcus were the most common bacterial genera from the conjunctival sac of adult (16/17; 94%) and kid (5/5; 100%) goats; three adults and 5 kids had no growth of bacteria on aerobic culture. Moraxella bovoculi was the most common single bacteria in adults, in 9 eyes (36%) of 8 animals (40%). Staphylococcus equorum was identified in all 5 kids with positive cultures. Mycoplasma sp. DNA was detected in 7 animals. Chlamydia sp. DNA was not detected in any sample. Four of 10 dam-kid pairs had identical bacteria isolated from the dams vaginal sample and the kids conjunctival sample. CONCLUSIONS Staphylococcus and Streptococcus were the most common conjunctival bacterial genera in this goatherd. Moraxella bovoculi was the most common single bacteria isolated from adults, and Staphylococcus equorum was the most common bacteria in kids. Mycoplasma sp. occurred infrequently at the ocular surface of adult and kid goats. A convincing association between dam-kid vaginal-conjunctival samples was not identified.

Exophthalmos due to sterile neutrophilic dermatosis in a dog

An 8-year-old castrated male Bichon Frise was presented to the Kansas State University Veterinary Health Center for evaluation of unilateral right-sided exophthalmos, suspected secondary to a retrobulbar abscess. The dog had acutely developed right-sided periorbital swelling, exophthalmos with pain on retropulsion, as well as multiple cutaneous exudative plaques on the feet and tail base. On ophthalmic examination, the dog also exhibited mild left-sided exophthalmos with decreased, nonpainful retropulsion. Orbital ultrasound and CT were performed to evaluate the extent of bilateral orbital disease. Incisional biopsies were obtained from the affected right periorbital tissues and skin of the feet, and histopathology revealed severe neutrophilic inflammation of the dermis with no organisms detected. Histologic changes were consistent with sterile neutrophilic dermatosis. The dog achieved clinical remission following treatment with initial immunosuppressive doses of corticosteroids and subsequent long-term maintenance therapy using oral cyclosporine.

Effects of topical ophthalmic application of 0.5% proparacaine hydrochloride on aerobic bacterial culture results for naturally occurring infected corneal ulcers in dogs

OBJECTIVE To evaluate the effects of topical ophthalmic application of 0.5% proparacaine hydrochloride solution (PHCL; containing 0.01% benzalkonium chloride as preservative) on aerobic bacterial culture results for naturally occurring infected corneal ulcers in dogs. DESIGN Clinical trial. ANIMALS 25 client-owned dogs with infected corneal ulcers (24 unilaterally affected and 1 bilaterally affected; only 1 eye included/dog) examined between June 2008 and May 2011. PROCEDURES Swab samples for aerobic bacterial culture were collected from the periphery of each corneal ulcer before and approximately 1 minute after topical ophthalmic application of 1 drop of PHCL. Numbers of aerobic bacterial species isolated from affected eyes were compared between sample collection points and between other variables (ie, side [left or right] of affected eye, prior treatments, and patient age, sex, and neuter status). RESULTS There was no significant difference between numbers of aerobic bacterial species isolated per eye or overall aerobic bacterial culture results (positive or negative) before versus after PHCL application. Similarly, prior treatment had no significant effect on aerobic bacterial culture results for samples collected at either point. The most commonly isolated bacteria before and after PHCL application were Staphylococcus spp (40% and 48%, respectively), followed by Streptococcus spp (23% and 22%, respectively). CONCLUSIONS AND CLINICAL RELEVANCE Topical ophthalmic application of PHCL did not significantly affect aerobic bacterial culture results for naturally occurring infected corneal ulcers in dogs as assessed in this study. Therefore, topical ophthalmic PHCL application could be useful in clinical settings prior to sample collection to relieve patient discomfort and to aid in sample acquisition without compromising aerobic bacterial culture results.

Effect of oral administration of robenacoxib on inhibition of paracentesis-induced blood-aqueous barrier breakdown in healthy cats

OBJECTIVE To determine the effect of oral administration of robenacoxib on inhibition of anterior chamber paracentesis (ACP)-induced breakdown of the blood-aqueous barrier (BAB) and assess whether robenacoxib can cross an intact BAB in healthy cats. ANIMALS 12 healthy adult domestic shorthair cats. PROCEDURES Cats received robenacoxib (6-mg tablet in a treat, PO; n = 6) or a control treatment (treat without any drug, PO; 6) once daily for 3 days, beginning 1 day before ACP. One eye of each cat served as an untreated control, whereas the other underwent ACP, during which a 30-gauge needle was used to aspirate 100 μL of aqueous humor for determination of robenacoxib concentration. Both eyes of each cat underwent anterior chamber fluorophotometry at 0 (immediately before), 6, 24, and 48 hours after ACP. Fluorescein concentration and percentage fluorescein increase were used to assess extent of ACP-induced BAB breakdown and compared between cats that did and did not receive robenacoxib. RESULTS Extent of BAB breakdown induced by ACP did not differ significantly between cats that did and did not receive robenacoxib. Low concentrations of robenacoxib were detected in the aqueous humor (mean, 5.32 ng/mL; range, 0.9 to 16 ng/mL) for 5 of the 6 cats that received the drug. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that oral administration of robenacoxib did not significantly decrease extent of BAB breakdown in healthy cats. Detection of low robenacoxib concentrations in the aqueous humor for most treated cats indicated that the drug can cross an intact BAB.