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.
To determine the effect of topical ophthalmic administration of 0.005% latanoprost solution on aqueous humor flow rate (AHFR) and intraocular pressure (IOP) in ophthalmologically normal dogs.
12 adult Beagles.
In a masked crossover design involving two 10-day experimental periods separated by a 7-day washout period, dogs were randomly assigned to first receive latanoprost or artificial tears (control) solution and then the opposite treatment in the later experimental period. Each experimental period was divided into a baseline phase (days 1 to 3), baseline fluorophotometry assessment (day 4), treatment phase (1 drop of latanoprost or artificial tears solution administered twice daily in each eye on days 5 to 9 and once on day 10), and posttreatment fluorophotometry assessment (day 10). Measured fluorescein concentrations were used to calculate baseline and posttreatment AHFRs. The IOP was measured 5 times/d in each eye during baseline and treatment (days 5 to 9) phases.
Mean baseline and posttreatment AHFR values did not differ significantly in either experimental period (latanoprost or control). In the latanoprost period, mean IOP was significantly lower during treatment than at baseline; there was no difference in corresponding IOP values during the control period. In the latanoprost period, mean IOP was significantly higher on the first day of treatment than on subsequent treatment days.
CONCLUSIONS AND CLINICAL RELEVANCE
In ophthalmologically normal dogs, topical ophthalmic administration of 0.005% latanoprost solution significantly decreased IOP but did not affect AHFR. Thus, the ocular hypotensive effect of latanoprost did not appear to have been caused by a reduction in aqueous humor production. (Am J Vet Res 2019;80:498–504)
To describe the prevalence of ocular lesions in cats with newly diagnosed histoplasmosis.
55 client-owned domestic cats.
As part of this prospective case series, cats diagnosed with histoplasmosis between the years 2015 and 2020 underwent complete ophthalmic examinations by a board-certified veterinary ophthalmologist prior to the initiation of antifungal treatment. Histoplasmosis was diagnosed by consistent clinical findings and identification of Histoplasma yeast on pathology or by the use of a commercially available enzyme immunoassay to detect Histoplasma antigen in urine.
Of the 55 cats, 45 (82%; 95% CI, 72% to 92%) had signs of active anterior, posterior, or panuveitis. The most common lesions were identified in the posterior portion of the globe and included chorioretinitis and partial retinal detachments (44/55 [80%; 95% CI, 69% to 90%] cats).
Detailed ophthalmic examinations should be performed on all cats with diagnosed or suspected histoplasmosis, as ocular involvement and subsequent vision loss are common.
To evaluate and compare regulation of diabetes mellitus (DM) in dogs with cataracts and well-controlled DM that received an ophthalmic preparation of prednisolone acetate versus diclofenac sodium.
22 client-owned dogs with cataracts and well-controlled DM.
A prospective, randomized, double-masked, experimental study was conducted. On days 0 and 32, serum fructosamine concentrations (SFCs), clinical scores, and body weights were determined. Dogs were assigned to receive a topically administered ophthalmic preparation of either prednisolone acetate 1% or diclofenac sodium 0.1% in each eye 4 times daily for 28 days. Data analysis was conducted with generalized linear mixed models.
Findings indicated no meaningful differences in SFCs, clinical scores, or body weights between the treatment groups on days 0 or 32. Clinical score on day 0 was positively associated with SFC, as indicated by the corresponding rate of change such that each 1 -unit increase in clinical score was associated with an approximately 45.6 ± 9.4 μmol/L increase in SFC. In addition, the least squares mean ± SEM SFC was higher in spayed females (539.20 ± 19.23 μmol/L; n = 12) than in castrated males (458.83 ± 23.70 μmol/L; 8) but did not substantially differ between sexually intact males (446.27 ± 49.72 μmol/L; 2) and spayed females or castrated males regardless of the treatment group assigned.
CONCLUSIONS AND CLINICAL RELEVANCE
Findings indicated no evidence for any differential effect on DM regulation (assessed on the basis of SFCs, clinical scores, and body weights) in dogs treated topically with an ophthalmic preparation of prednisolone versus an ophthalmic preparation of diclofenac. Additional research investigating plasma concentrations of topically applied ophthalmic glucocorticoid medications is warranted. (Am J Vet Res 2019;80:1129-1135)