Objective—To assess expression of cyclooxygenase (COX)-1 and -2 in naturally occurring squamous cell carcinomas (SCCs) and the analogous normal tissues in horses.
Sample Population—Tissue samples collected from 3 conjunctival, 2 vulvar, 4 preputial, and 5 penile SCCs during surgical excision in 14 horses and from corresponding body regions (conjunctiva [n = 5 horses], vulva , prepuce , and penis ) in 5 horses euthanized for reasons unrelated to neoplasia.
Procedures—Tissue samples were snap frozen in liquid nitrogen and stored at −80°C until analysis. Protein was extracted from the frozen tissues, and western blot analyses were performed. Nonneoplastic and abnormal tissues from each body region were run on the same blot, and blots were run in triplicate. Molecular-weight markers and COX-1 and 2 ovine standards (positive control samples) were run concurrently on the gels; negative control samples were not used.
Results—All tissues, including the nonneoplastic and SCC tissues, expressed both COX-1 and -2 proteins.
Conclusions and Clinical Relevance—Results indicated that the expression of COX proteins in both nonneoplastic and SCC-affected tissues in horses is markedly different from that in other species. The reason for the potential benefit of COX-2 inhibitors in horses and other species is unknown. Further research needs to be performed to evaluate the efficacy of COX-2 inhibitors as cancer treatments in horses. Investigation of the mechanisms of tumor development in horses should be performed to increase understanding of this disease and ascertain how the mechanisms differ from those in other animals.
Objective—To generate data on the effects of firocoxib administration to horses with osteoarthritis.
Animals—Client-owned horses with signs of lameness and joint pain associated with osteoarthritis.
Procedures—Firocoxib was administered as an oral paste (0.1 mg/kg, q 24 h) for 14 days. Assessments were performed on day 0 (baseline) and days 7 and 14.
Results—390 of 429 horses from 80 sites in 25 states met the criteria for analysis. Quarter Horse and Thoroughbred were the 2 most commonly represented breeds, comprising half of the study population. Signs of musculoskeletal pain or lameness attributed to osteoarthritis were diagnosed in a single joint in 197 (197/390 [50.5%]) horses and in multiple joints in 193 (193/390 [49.5%]) horses. In those with involvement of a single joint, the tarsus was the most frequently affected joint (79/197 [40.1 %]). Among the 390 horses with complete lameness data, improvement was reported in approximately 80% by day 14. Investigators rated 307 (78.7%) horses as improved, whereas owners or handlers rated 316 (81.0%) horses as improved at the termination of the study. Horses treated with firocoxib paste had significant improvement in lameness scores from baseline values. Improvement was most rapid within the first 7 days after starting treatment and continued, albeit at a slower rate, through treatment day 14.
Conclusions and Clinical Relevance—Firocoxib significantly improved lameness scores throughout the 14-day period with few adverse effects. Firocoxib can be a safe cyclooxygenase-2–specific NSAID for the treatment of musculoskeletal pain and lameness associated with osteoarthritis.
Objective—To identify risk factors for development of acute laminitis in horses during hospitalization for illness or injury.
Design—Retrospective case-control study.
Animals—73 horses that developed laminitis (case horses) and 146 horses that did not develop laminitis (control horses) during hospitalization.
Procedures—Case and control horses were matched in a 2:1 ratio by the date on which each horse was evaluated. Potential risk factors investigated included age, breed, and sex; highest and lowest values recorded during hospitalization for fibrinogen concentration, WBC count, PCV, and total solids concentration; and comorbid disease states, including pneumonia, endotoxemia, diarrhea, medically treated colic, surgically treated colic, pituitary adenoma, retained placenta or metritis, forelimb lameness, hind limb lameness, acute renal failure, and vascular abnormalities. A univariate screening of all potential risk factors was performed to determine which variables should be selected for further analysis. All factors found to be associated with development of laminitis were included in a multivariate conditional logistic regression model.
Results—Development of laminitis was marginally associated with lowest and highest fibrinogen concentrations, highest PCV, and lowest total solids concentration and significantly associated with pneumonia, endotoxemia, diarrhea, abdominal surgery for colic, and vascular abnormalities. In the multivariate analysis, only endotoxemia was significantly associated with laminitis.
Conclusions and Clinical Relevance—Endotoxemia is an important risk factor for development of acute laminitis in horses during hospitalization for medical or surgical conditions. Early recognition of endotoxemia, or the potential for it to develop in certain disease states, and initiation of treatment directed at endotoxemia or its consequences may help prevent laminitis in horses during hospitalization.
Objective—To describe the pool-raft recovery system protocol and to evaluate the clinical outcome inhorses that underwent recovery from general anes-thesia using this system.
Animals—393 horses that underwent recovery fromgeneral anesthesia in the pool-raft system.
Procedure—Anesthetic records were examined fromhorses recovered from anesthesia in the pool-raft sys-tem between January 1984 and December 2000.Complete medical records of horses were examinedwhen available. Information regarding the anestheticand recovery period was recorded. Horses first recov-ered from general anesthesia in the pool-raft and,once awake, were transported to a recovery stall andlowered to the floor in a standing position.
Results—351 horses underwent 1 pool-raft recovery,and 42 horses underwent multiple pool-raft recover-ies. Most horses were recovered from general anes-thesia within the pool-raft system to safeguard repairof a major orthopedic injury. During 471 pool-raftrecoveries, 34 (7%) horses had complications withinthe recovery pool and 62 (13%) had complicationswithin the recovery stall. Deaths resulted from complete failure of internal fixation, pulmonary dysfunc-tion, or a combination of pulmonary dysfunction andfixation failure in 2% (10/471) of horses that under-went pool-raft recoveries.
Conclusions and Clinical Relevance—The pool-raftsystem is a good option for recovery from generalanesthesia. Although not a fail-safe system, itappears to decrease the complications of recoveringhorses in a high-risk category. Potential disadvan-tages of this system are added expense and man-power necessary in building, maintenance, andusage, as well as size limitations of the raft itself. (J Am Vet Med Assoc 2002;221:1014–1018)
Objective—To determine associations between age,
sex, or medical treatment and prevalence and severity
of gastric ulceration in Standardbred racehorses in
Animals—224 Standardbred racehorses in training.
Procedure—Gastroscopy was performed on each
horse, and mucosal ulceration was graded from 0
(normal mucosa, no lesions) to 3 (extensive, often
coalescing, lesions with areas of deep ulceration).
Associations between age, sex, or treatment and
prevalence and severity of ulcers were evaluated.
Results—Prevalence of gastric ulceration was 87%.
Although there was little association between age and
prevalence of ulcers, there was an association between
age and severity of ulcers. Most 2-year-old horses
(57.7%) had an ulcer score of 0 or 1. In all other age
groups, most (58% to 82.61%) of horses had an ulcer
score of 2 or 3. Although overall prevalence of ulceration
was comparable among sex groups, the relative risk for
gastric ulceration increased with age in castrated males,
whereas it decreased in females and sexually intact
Conclusions and Clinical Relevance—Gastric ulceration
is common in Standardbred horses in race training.
Severity is higher in horses ≥ 3 years of age than
in 2-year-old horses. Relative risk for ulceration
increases with age in castrated males. (J Am Vet Med Assoc 2002;221:1156–1159)