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The objective of this study was to determine to what extent the oculocardiac reflex (OCR) progressively rises with increasing external pressures over the superior eyelid. Controlled external weights were applied to the left eyelid of ten conscious healthy adult beagle dogs, using an electronic von Frey aesthesiometer with a modified probe. Four different weights (200 g, 300 g, 400 g and 800 g) were applied on four different non-consecutive days (with one-week intervals). Pressure was applied by pushing the device against the superior eyelid. The baseline heart rate was primarily recorded using an electrocardiograph (ECG). Then, indices of heart rate variability such as R-R intervals and vasovagal tonus index (VVTI) were calculated from the ECG tracings using twenty consecutive QRS complexes from each dog, before and after a selected set of graded weights were applied to the eye. Median R-R interval significantly increased when an external weight of 200 g was applied and peaked at 300 g. VVTI values peaked at 400 g. With higher pressures, the proportional increase was smaller in both R-R intervals and VVTI. We concluded that external eye pressure using a weight of 200 g or more is sufficient to elicit an OCR response in conscious dogs. Pressures above 400 g started to activate compensatory mechanisms that counteracted with the OCR, probably linked to an adrenergic response induced by the animal's discomfort. Changes in R-R intervals might be used as an early OCR marker, while VVTI apparently was less influenced by potential sympathetic responses. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the IOP values obtained from normal canine eyes, by means of the TonoVet Plus (TVP) and TonoPen Avia (TPA), and compare them to an established tonometer, the TonoVet (TV). Methods: Tonometry was performed bilaterally in 50 healthy dogs, age 1‐11 years. The rebound tonometers (TV and TVP) were used first (in a random order), and then, one drop of tetracaine hydrochloride was applied to each eye, and approximately one minute later the IOP was estimated using the TPA. The mean ± standard deviation (SD) was calculated for each tonometer and a paired Student's t test was used to compare the IOP values between tonometers. A P value ≤.05 was considered significant. The agreement between tonometers was assessed by a Bland‐Altman plot. Results: The mean ± SD (range) IOP values were 15.0 ± 3.2 mm Hg (7‐22), 19.2 ± 3.1 mm Hg (11‐25), and 12.8 ± 2.9 mm Hg (6‐19), for the TV, TVP, and TPA, respectively. The IOP values obtained by each tonometer were significantly different compared to the other two (P <.0001). There was a good agreement with fixed bias between all tonometers. Conclusions: The average IOP values of the TVP were significantly higher than those of the TV, which were significantly higher than those of the TPA, in normal canine eyes. Knowing the normal IOP values for these tonometers and the bias between them will help the clinician with the interpretation of IOP values obtained by these devices and compare between them. [ABSTRACT FROM AUTHOR]

Objective: To describe the clinical application and effect of MicroPulse™ transscleral cyclophotocoagulation (MP‐TSCPC) in dogs with glaucoma. Animals studied: Twelve dogs with primary (n = 8) or secondary (n = 4) glaucoma, aged 2‐13 years (mean ± SD, 7.2 ± 3.8 years). Procedures: MP‐TSCPC was performed under sedation or general anesthesia. Laser duty cycle was 31.3%, laser power varied from 2000‐2800 mW, and each hemisphere was treated for 90‐180 seconds. The probe was applied to each quadrant in a "sweeping motion," sparing the 3 and 9 o'clock positions. Results: The number of MP‐TSCPC procedures per eye varied from 1 to 3 (1.4 ± 0.7). Intraocular pressure (IOP) was controlled (<25 mm Hg) in 11/12 dogs (92%) within 1‐15 days post‐operatively. The IOP control at 1 month and the duration between repeated procedures were significantly greater in eyes treated with high energy laser (2800 mW) compared to 2000‐2500 mW. Long‐term follow‐up (315.3 ± 100.7 days) showed controlled IOP in 5/12 (42%) and vision retention in 4/8 (50%) dogs. In unsuccessful cases, loss of IOP control or vision loss occurred within 3‐245 days (109.1 ± 93.7 days) and 28‐261 days (114 ± 101.6 days), respectively, resulting in a salvage procedure in 6 dogs. Complications were as follows: corneal hypoesthesia (92%), anterior uveitis (67%), post‐operative ocular hypertension (50%), neurotrophic corneal ulcer (25%), keratoconjunctivitis sicca (8%), and rubeosis iridis (8%). Conclusions: MP‐TSCPC is a viable tool for managing canine glaucoma, although further studies are required to improve the long‐term effect and reduce the complication rate. [ABSTRACT FROM AUTHOR]

Objective: To investigate microbial contamination of canine plasma eye drops when used clinically and to compare the effect of two different eyedropper bottles on contamination rate. Methods: Forty‐six bottles containing plasma were randomly dispensed for use on 42 dogs with ulcerative keratitis. Of these, 23 were standard eyedropper bottles and 23 were Novelia® bottles designed to prevent contamination. After use for up to 2 weeks, samples for bacterial culture were obtained from a drop of plasma, the bottle tip, the plasma inside the bottle, and the corneal surface. Fungal culture was performed from a drop of plasma. Results: The overall microbial contamination rate was 17.4% (8/46 bottles); however, only one bottle had growth from the plasma inside the bottle. There was a lower contamination rate of Novelia® bottles (3/23 = 13.0%) compared to standard bottles (5/23 = 21.7%), but this difference was not statistically significant (P =.57). There were also no significant differences in contamination rate of bottles used greater than 7 days compared to less than or equal to 7 days, or in bottles used greater than 4 times daily compared to 4 times daily or less. Three corneal samples (6.5%) had bacterial growth, but none matched contamination from the bottles. Conclusions: Novelia® bottles may decrease contamination of plasma eye drops used clinically. However, while microbial contamination of plasma bottles was documented, no clinically relevant complications were observed. This study supports safe use of plasma eye drops for up to 2 weeks when refrigerated and dispensed from either Novelia® or standard eyedropper bottles. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: Labial mucosa transplantation for the treatment of canine keratoconjunctivitis sicca (KCS) has been reported recently. Postoperative alleviation of clinical signs was noted and assumed to be the result of labial salivary glands providing lubrication to the ocular tissue. The aim of this study was to evaluate the presence of minor salivary glands (MSG) in the canine oral mucosa. Methods: Oral mucosal biopsies were collected from six dogs that died (n = 1) or were euthanized (n = 5) for reasons unrelated to this study. The breeds included were two Doberman Pinschers, one Labrador Retriever, one Portuguese Water Dog, one German Shepherd Dog, and one mixed canine. Three were spayed females, and three were castrated males with the median age of 9 years (range, 6–13 years). Samples were obtained by an 8‐mm punch biopsy at the following locations of the canine oral cavity: upper rostral labial mucosa at midline, lower rostral labial mucosa at midline, upper labial mucosa near the commissure, lower labial mucosa near the commissure, and buccal mucosa approximately 1 cm caudal to the commissure. Samples were routinely processed with hematoxylin and eosin, and periodic acid–Schiff stains. Samples were evaluated by light microscopy. Results: At the selected locations, no MSG or other secreting cells were detected. Conclusions: Minor salivary glands are not associated with alleviation of canine KCS symptoms following labial mucosa transplantation. Further studies are needed to determine the mechanism leading to the transient improvement of KCS symptoms in canine patients following labial mucosa transplantation. [ABSTRACT FROM AUTHOR]

Objective To evaluate the effect of topical ophthalmic 0.005% latanoprost alone and in combination with 0.1% diclofenac on healthy horses. Animals studied Twelve healthy adult horses. Procedures A randomized, masked crossover design was used with horses divided into three groups for once daily treatment in one randomly selected eye. For arm 1 of the study, Group D ( n = 3) received 0.1% diclofenac, Group L ( n = 3) received 0.005% latanoprost, and Group DL ( n = 6) received 0.005% latanoprost and 0.2 ml of 0.1% diclofenac. For arm 2 of the study, horses from Group D and L were placed into Group DL and horses from Group DL were placed into either Group D or L. Evaluations of intraocular pressure ( IOP), vertical pupil diameter, aqueous flare, conjunctival hyperemia, epiphora, blepharospasm, and blepharoedema were performed 4 times daily on days 1 and 2 (baseline), days 3 to 7 (arm 1 treatment), days 8 to 11 (washout), days 12 to 16 (arm 2 treatment), and days 17 and 18 (return to baseline). Results During the treatment period, significant reduction in IOP and vertical pupil diameter occurred in treated eyes of Groups L and DL, but not Group D. These variables did not differ significantly between Groups L and DL. Blepharospasm, blepharoedema, epiphora, and conjunctival hyperemia scores were significantly higher in Group L than in Groups D and DL. Conclusions Latanoprost reduced IOP in healthy horses and signs of drug-induced discomfort were mitigated by concurrent use of diclofenac. [ABSTRACT FROM AUTHOR]

Objective To determine if topical ophthalmic diclofenac sodium 0.1% solution alters renal parameters in the domestic chicken, and to determine if the drug is detectable in plasma after topical ophthalmic administration. Animals Thirty healthy domestic chickens. Procedures Over 7 days, six birds were treated unilaterally with one drop of artificial tear solution (group 1), 12 birds were treated unilaterally (group 2) and 12 bilaterally (group 3) with diclofenac sodium 0.1% ophthalmic solution. Treatments were provided every 12 h in all groups. Pre- and post-treatment plasma samples from all birds were evaluated for changes in albumin, total protein, and uric acid. Post-treatment samples of all birds, collected 15 min post-administration, were analyzed by high-performance liquid chromatography with mass spectrometry for diclofenac sodium detection. A randomly selected renal sample from each group was submitted for histopathologic review. Results Changes in pre- and post-treatment plasma albumin were significant ( P < 0.05) in groups 2 and 3, but not for group 1. Pre- and post-treatment changes in total protein and uric acid were not significant for any group. Diclofenac sodium was not detectable (limit of detection = 0.10 ng/mL) in plasma samples from birds in group 1. Post-treatment concentration of diclofenac in group 3 was statistically greater than group 2 ( P = 0.0008). Histopathologic changes did not identify diclofenac-induced acute renal tubular necrosis. Conclusions Ophthalmic diclofenac sodium 0.1% administered topically every 12 h in one or both eyes for 7 days is detectable in systemic circulation in the domestic chicken, but does not cause overt significant changes in plasma uric acid or total protein. [ABSTRACT FROM AUTHOR]