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Abstract

Objective—To evaluate effects of intracameral injection of preservative-free 1% and 2% lidocaine hydrochloride solution on the anterior segment of the eyes in dogs.

Animals—16 adult healthy dogs (8 male and 8 female) judged to be free of ocular disease.

Procedure—Dogs were randomly assigned to 2 groups of 8 dogs each. Group 1 dogs received an intracameral injection of 0.10 mL of preservative-free 1% lidocaine solution in the designated eye, and group 2 dogs received 0.10 mL of preservative-free 2% lidocaine solution in the designated eye. After injection, intraocular pressure was measured every 12 hours for 48 hours and then every 24 hours until 168 hours after injection. Slit-lamp biomicroscopy was performed preceding intracameral injection, 8 hours after injection, and then every 24 hours until 168 hours after injection. Ultrasonic pachymetry and specular microscopy were performed preceding intracameral injection and 72 and 168 hours after injection. Corneal thickness and endothelial cell density and morphology were compared with baseline measurements.

Results—No significant differences were found in intraocular pressure, corneal thickness, endothelial cell density, and morphologic features in either group, compared with baseline. A significant difference in aqueous flare was found for treated and control eyes 8, 24, and 48 hours after injection, compared with baseline. No significant difference in aqueous flare was found between treated and control eyes within either group.

Conclusions and Clinical Relevance—No adverse ocular effects were detected after intracameral injection of preservative-free 1% or 2% lidocaine solution; thus, its use would be safe for intraocular pain management in dogs. (Am J Vet Res 2004;65:1325–1330)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate, for clinically normal dogs, results of Schirmer tear tests in eyes without topical anesthetic (STT) and to detect differences associated with breed, sex, age, day, and time of day in eyes in which STT was performed after use of topical anesthetic (STTa).

Animals—41 Beagles, 43 Labrador Retrievers, 25 Golden Retrievers, 26 English Springer Spaniels, and 22 Shetland Sheepdogs.

Procedure—Beagles had STT and STTa values measured twice daily for 5 days. Client-owned dogs of 4 other breeds had STT and STTa values measured once.

Results—Mean ± SD values of Beagles for STT and STTa were 20.2 ± 2.5 and 3.8 ± 2.7 mm/min. Mean values for STT and STTa were as follows: Labrador Retriever, 22.9 ± 4.1 and 9.6 ± 3.8 mm/min; English Springer Spaniel; 20.7 ± 3.2 and 5.4 ± 3.4 mm/min; Golden Retriever, 21.8 ± 3.7 and 8.8 ± 3.1 mm/min; and Shetland Sheepdog, 15.8 ± 1.8 and 3.6 ± 2.8 mm/min. Overall mean values for STT and STTa were 20.2 ± 3.0 and 6.2 ± 3.1 mm/min. Differences for STT and STTa were detected among breeds, but significant differences were not associated with sex or age within each breed or in overall values for all dogs.

Conclusions and Clinical Relevance—Results for the STT reported here compare favorably with reported values, except for results of Shetland Sheepdogs; however, results for the STTa differ dramatically from reported values. Clinicians should consider effects attributable to breed when evaluating results of STT and STTa in dogs. (Am J Vet Res 2000; 61:1422–1425)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To describe the use of hydropulsion with sterile isotonic buffered ophthalmic solution (ie, eyewash) for the treatment of superficial corneal foreign bodies in veterinary patients and evaluate signalment, clinical findings, and outcomes following the procedure.

Design—Retrospective case series.

Animals—11 dogs, 2 cats, and 2 horses.

Procedures—Medical records were retrospectively reviewed to identify patients that underwent hydropulsion treatment for a superficial, nonpenetrating corneal foreign body confirmed by ophthalmic examination. Data regarding signalment, reason for evaluation, ocular diagnoses, and treatment were recorded. Hydropulsion was performed with a 6-mL syringe filled with eyewash solution and a 25-gauge needle with the needle tip removed. Owners and referring veterinarians of patients that did not have a recheck examination recorded were contacted by telephone for follow-up information.

Results—The corneal foreign body was an incidental finding in 3 of 15 patients. The most common clinical signs included blepharospasm, conjunctival hyperemia, and corneal vascularization. Hydropulsion was successful for foreign body removal in all 15 cases. No complications were observed during or following the procedure. In the 9 patients that had a follow-up examination, the cornea tested negative for retention of topically applied fluorescein (with a mean of 6.3 days from treatment to follow-up). At the time of last follow-up examination or telephone follow-up, no patients were reported to have clinical signs of ocular discomfort or corneal opacity associated with the affected site.

Conclusions and Clinical Relevance—In these patients, hydropulsion was easily performed with readily available materials and was successful for the removal of superficial corneal foreign bodies with no adverse effects.

Full access
in Journal of the American Veterinary Medical Association

Objective

To evaluate clinical signs of ocular blastomycosis in dogs, to determine response of blastomycosis-infected eyes to treatment with systemically administered amphotericin B and ketoconazole, and to identify prognostic indicators of successful antifungal treatment.

Design

Retrospective study.

Animals

73 dogs.

Procedure

Medical records were reviewed for all dogs with confirmed blastomycosis and ocular disease seen at our hospital between 1985 and 1993.

Results

6 eyes had anterior segment disease, 24 had posterior segment disease, and 78 had endophthalmitis. 40 eyes were treated with a combination of amphotericin B and ketoconazole, and 16 of the 40 responded favorably. However, 16 of the 24 eyes that were not severely affected responded favorably, but none of the 16 eyes that were severely affected did.

Clinical Implications

Dogs with blastomycosis had posterior segment disease, without complete retinal separation, had a good prognosis for retaining vision. Results of histologic examination suggested that secondary glaucoma was a manifestation of endophthalmitis and was indicative of a grave prognosis for response to antifungal and antiglaucoma treatment. (J Am Vet Med Assoc 1996;209:1271–1274)

Free access
in Journal of the American Veterinary Medical Association

Summary

Eye enucleations performed on 109 dogs, 29 horses, and 23 cats involved placement, of 136 silicone orbital implants and 7 mesh implants. Mean follow-up times were 2.4 years (range, 3 weeks to 9 years) in dogs, 3.4 years (range, 10 days to 10.5 years) in horses, and 1.5 years (range, 3 weeks to 7.5 years) in cats. Implants failed in 1 of 96 dogs (1.04%), 3 of 29 horses (10.3%), and 3 of 18 cats (16.7%). Implant failure was attributable to various causes in all species; however, cats appeared to be more prone to late extrusion than were dogs and horses. Implantation of an orbital prosthesis was a safe and inexpensive method for improving cosmetic appearance after enucleation in dogs, horses, and cats.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the electrodiagnostic and histologic response of short-term increases of intraocular pressure (IOP) on transient pattern electroretinograms (PERG) and flash electroretinograms (FERG) in the eyes of dogs.

Animals—8 healthy mixed-breed dogs.

Procedure—Transient PERG and FERG waveforms were recorded from dogs (while anesthetized) as IOP was increased from baseline (7 to 19 mm Hg) to 90 mm Hg. One hundred mean PERG responses and a single FERG response were recorded at each step during 3 recording sessions. Globes of each dog were enucleated after euthanasia on posttreatment day 7 and evaluated by a pathologist.

Results—Increases in spatial frequency resulted in decreased amplitudes of N2 (second negative PERG peak). Increases in IOP resulted in decreases in all 3 PERG waveforms and the FERG waveform. All values began to return to baseline after short-term increases in IOP on day 0, and waveforms were not significantly different on posttreatment days 3 and 7.

Conclusions—Data suggest that short-term increases in IOP affect PERG and FERG waveforms, and PERG waveforms are more sensitive to increases in IOP. Differences were not detected between treated and control eyes on histologic examination. Further studies are necessary to determine at what IOP permanent damage to ganglion and photoreceptor cells will develop and whether PERG is a reliable clinical diagnostic technique for use in dogs to reveal retinal damage that is secondary to increased IOP prior to changes in waveforms generated by FERG in dogs. (Am J Vet Res 2000;61:1087–1091)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the characteristics of, prevalence of, and risk factors for corneal pigmentation (CP) in Pugs.

Design—Prospective cross-sectional study.

Animals—295 Pugs > 16 weeks old.

Procedures—Ophthalmic examination of the anterior segment of each eye was performed, including determination of tear film characteristics (Schirmer tear test and tear film breakup time) and corneal sensitivity. Digital photographs of the head and each eye were obtained. Corneal pigmentation of eyes was graded as absent, very mild, mild, moderate, or severe. Signalment and medical history information and American Kennel Club registration status were recorded.

Results—CP was detected in at least 1 eye of 243 of the 295 (82.4%) Pugs; CP was typically very mild or mild. Detection of CP was not significantly associated with coat color, age, eyelid conformation, or tear film characteristics but was significantly associated with sex of dogs. The severity of CP was not significantly associated with American Kennel Club registration status or age, but was significantly associated with sex, tear film characteristics, and coat color. Iris hypoplasia was detected in 72.1% of the Pugs. Iris-to-iris persistent pupillary membranes were detected in 85.3% of the Pugs.

Conclusions and Clinical Relevance—Prevalence of CP in Pugs in this study was high. Unexpectedly high prevalences of iris hypoplasia and persistent pupillary membranes were also identified. The condition identified in these Pugs was a pigmentary keratopathy, rather than pigmentary keratitis or corneal melanosis. This condition may have a genetic basis, and further studies are warranted to determine etiology.

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To determine tear film concentrations of doxycycline in ophthalmologically normal dogs following oral doxycycline administration.

DESIGN Crossover study.

ANIMALS 10 privately owned dolichocephalic or mesaticephalic dogs free of ophthalmic disease.

PROCEDURES Dogs were randomly assigned to receive doxycycline hyclate first at 5 mg/kg (2.3 mg/lb) or 10 mg/kg (4.5 mg/lb), PO, every 12 hours for 5 days, beginning on day 1. Doxycycline was administered 1 hour prior to feeding. Tear samples were collected from days 1 through 10 approximately 3 hours after the morning dose was administered. Following a 3-week washout period, dogs received the alternative dose in the same conditions. Doxycycline concentration in tear samples from 1 eye (same eye used for both sessions) was measured via liquid chromatography–mass spectrometry and compared between the 2 doxycycline doses.

RESULTS Doxycycline was detected in tear samples of all dogs from days 1 through 10 for both doxycycline doses. Median peak doxycycline concentrations for the 5 mg/kg and 10 mg/kg doses were 2.19 ng/mL on day 3 and 4.32 ng/mL on day 4, respectively. Concentrations differed significantly with time, but this difference was not influenced by dose, dose order, or eye. A significant positive correlation was identified between doxycycline concentration and body weight (r = 0.22).

CONCLUSIONS AND CLINICAL RELEVANCE Detectable doxycycline concentrations were achieved in the tear film of ophthalmologically normal dogs following oral administration of doxycycline at 5 or 10 mg/kg, every 12 hours. Dose had no significant effect on tear film concentration of the drug.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To develop and test a noninvasive technique for determining age in dogs and cats on the basis of changes in lens reflections and transparency.

Animals

85 dogs representing 5 breeds and 73 domestic shorthair cats.

Procedure

While examining dilated eyes in a darkened room, using a penlight, 2 experienced examiners who were blinded to actual age of animals individually measured the diameter of reflections from the anterior (La) and posterior (Lb) surfaces of the lens and scored lens transparency (Ltr) from 1 (clear) to 5 (severe opacity). Models were developed to predict age on the basis of these measurements.

Results

Aging models developed for dogs and cats were as follows: Agedogs = 2.197 − 0.070 × (La) + 1.361 × (Lb) + 1.193 × (Ltr) and Agecats = 1.988 + 1.024 × (La) + 2.220 × (Lb) + 1.019 × (Ltr), where age was expressed in years, and La and Lb were in millimeters. All variables, except La in dogs, contributed significantly to accuracy of the models. Correlation between predicted and actual ages, as measured by Pearson's product-moment correlation coefficient, was significant in both species (P < 0.0001). Significant differences were not found between examiners or between the first and second evaluations by the same examiner.

Conclusions and Clinical Relevance

A noninvasive technique based on evaluation of lens reflections and transparency can provide clinically useful predictions of age in mature dogs and cats. This technique could be an important tool for veterinarians or humane shelters in determining differential diagnoses and assessing longevity and adoptability of mature animals of unknown age. (Am J Vet Res 1998;59:945–950)

Free access
in American Journal of Veterinary Research

Summary

Fibrin dots were induced in eyes of dogs by injection of autogenous citrated plasma into the anterior chamber. Twenty-four hours after dot formation, one 50-μl drop of tissue plasminogen activator at a concentration of 5 mg/ml (group 1, n = 7) was administered topically 9 times at 5-minute intervals, or a collagen shield that was hydrated with tissue plasminogen activator at a concentration of 5 mg/ml (group 2, n = 7) was applied. The contralateral eye served as a nontreated control. Serial photographs were taken of the fibrin dots after topical application of tissue plasminogen activator. Computerized morphometric analysis was then used to evaluate changes in cross-sectional surface area of the fibrin dot. There was no significant mean percentage decrease in dot surface area of treated eyes of group-1 dogs or in treated eyes of group-2 dogs. In addition, there was no significant difference in mean percentage decrease in dot surface area between treated eyes of group-1 and group-2 dogs.

Free access
in American Journal of Veterinary Research