Objective—To determine effects after topical administration of latanoprost, timolol, or a commercially available latanoprosttimolol combination twice daily on intraocular pressure (IOP), pupil size (PS), and heart rate (HR) in clinically normal dogs.
Animals—17 clinically normal dogs.
Procedures—A randomized controlled clinical trial was performed with a treatment (n = 9) and saline (0.9% NaCl) solution group (8). Each dog in the treatment group received 3 treatments (latanoprost, timolol, and the latanoprost-timolol combination), with a 14-day washout period between treatments. Baseline values were established on day 1 of each treatment period. On days 2 through 5, drugs were administered topically every 12 hours to 1 eye of each dog in the treatment group. In both groups, IOP PS, and HR were measured at 0, 2, 4, 6, 8, and 9 hours on days 2 and 5.
Results—Eyes treated with latanoprost or the latanoprost-timolol combination had a significant decrease in IOP and a significantly smaller PS, compared with results for dogs receiving only timolol or dogs in the saline solution group. Timolol and the latanoprost-timolol combination both significantly lowered HR, compared with HR following administration of latanoprost and the saline solution.
Conclusions and Clinical Relevance—Topical administration of latanoprost alone was as effective at lowering IOP as was administration of the latanoprost-timolol combination when both were given every 12 hours to clinically normal dogs. Timolol, either alone or in combination with latanoprost, appeared to have little or no effect on IOP in clinically normal dogs but was associated with a reduction in HR. (Am J Vet Res 2010;71:1055–1061)
Objective—To evaluate concordance among veterinary
pathologists in the assessment of histologic findings
in the pars intermedia of pituitary gland sections
from aged horses with mild signs suggestive of pituitary
pars intermedia dysfunction (PPID).
Sample Population—10 pituitary glands from aged
Procedure—7 pathologists were provided with signalment,
clinical signs, and a single H&E-stained pituitary
gland section from 10 aged horses with mild
signs suggestive of PPID. Pathologists described histologic
findings for each section and stated whether
findings were consistent with PPID. Agreement
among pathologists and with antemortem diagnostic
test results was calculated.
Results—Overall, only fair agreement was found
among the pathologists as to which horses had histologic
findings consistent with disease (mean ± SE
kappa value, 0.34 ± 0.069). Interpretation of individual
sections varied, with minimal agreement (4 or 5/7
pathologists) for 5 of 10 sections evaluated.
Postmortem assessment was in agreement with an
antemortem endocrine diagnostic test result 79% of
Conclusions and Clinical Relevance—Validation of
antemortem diagnostic testing for PPID in horses
often relies on the results of postmortem histologic
evaluation. The lack of consensus in histologic interpretation
of pituitary glands from aged horses with
mild clinical signs in our study indicates that postmortem
histologic evaluation of pituitary glands is an
inappropriate standard in validation of antemortem
diagnostic tests for detection of early PPID. Caution
should be used when interpreting diagnostic test
results in horses in which early PPID is suspected.
(Am J Vet Res 2005;66:2055–2059)
Objective—To determine prevalence of anthelmintic resistance on sheep and goat farms in the southeastern United States.
Animals—Sheep and goats from 46 farms in 8 southern states, Puerto Rico, and St Croix in the US Virgin Islands.
Procedures—Parasite eggs were isolated from fecal samples, and susceptibility to benzimidazole, imidathiazole, and avermectin-milbemycin anthelmintics was evaluated with a commercial larval development assay.
Results—Haemonchus contortus was the most common parasite on 44 of 46 farms; Trichostrongylus colubriformis was the second most commonly identified parasite. Haemonchus contortus from 45 (98%), 25 (54%), 35 (76%), and 11 (24%) farms were resistant to benzimidazole, levamisole, ivermectin, and moxidectin, respectively. Resistance to all 3 classes of anthelmintics was detected on 22 (48%) farms, and resistance to all 3 classes plus moxidectin was detected on 8 farms (17%).
Conclusions and Clinical Relevance—Findings provided strong evidence that anthelmintic resistance is a serious problem on small ruminant farms throughout the southeastern United States. Owing to the frequent movement of animals among regions, the prevalence of resistance in other regions of the United States is likely to also be high. Consequently, testing of parasite eggs for anthelmintic resistance should be a routine part of parasite management on small ruminant farms.