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in Journal of the American Veterinary Medical Association

Summary

Acute hepatic disease was diagnosed in 16 horses during the study period. Twelve of those cases were characterized as idiopathic acute hepatic disease (iahd). In 9 of the 12 (75%) cases of iahd, the horses were female, and 7 of the 9 females were lactating and had been treated with tetanus antitoxin at parturition. Diagnosis of iahd was based on anamnesis, clinical signs, and results of serum biochemical analyses, hepatic biopsy, and postmortem examination. Within 1 year of the illness, 75% (9/12) of the horses had died or had been euthanatized. Not all horses had the typical fulminant signs associated with iahd and in those horses, serum biochemical analyses were particularly helpful in diagnosis. Because tetanus antitoxin administration seemed to be associated with iahd, use of tetanus antitoxin is not without risk, and routine administration of tetanus antitoxin, particularly to parturient mares, should be discouraged.

Free access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate expression of cyclooxygenase (COX)-1 and COX-2 in the cornea, eyelid, and third eyelid of healthy horses and those affected with squamous cell carcinoma (SCC) by use of immunohistochemical techniques.

Animals—15 horses with SCC involving ocular tissues and 5 unaffected control horses.

Procedures—SCC-affected tissues were obtained from the cornea (n = 5 horses), eyelid (5), and third eyelid (5). Site-matched control tissues were obtained from 5 horses unaffected with SCC. Tissue sections of affected and control cornea, eyelid, and third eyelid were stained immunohistochemically for COX-1 and COX-2 via standard techniques. Stain uptake was quantified by use of computer-assisted image analysis of digital photomicrographs.

Results—Immunoreactivity for both COX-1 and COX-2 was significantly greater in equine corneas with SCC than in control corneas. No significant differences in COX-1 or COX-2 immunoreactivity were detected in eyelid and third-eyelid SCC, compared with site-matched control tissues.

Conclusions and Clinical Relevance—Immunoreactivity for COX-1 and COX-2 is high in equine corneal SCC, possibly indicating that COX plays a role in oncogenesis or progression of this tumor type at this site. Pharmacologic inhibition of COX may represent a useful adjunctive treatment for corneal SCC in horses.

Full access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To determine the following: (1) whether an irrigation solution that is hyperosmolar (HYPER) relative to synovial fluid decreases tissue extravasation during an arthroscopic protocol when compared to a relatively hypoosmolar solution, (2) the safety of a HYPER solution based on viability of joint tissues following joint irrigation, and (3) if the use of a HYPER solution decreases water content in stifle joint tissue.

ANIMALS

8 adult horses.

PROCEDURES

A prospective, blinded, randomized controlled trial was performed to compare lactated Ringer’s solution (LRS; 273 mOsm/L) and a HYPER (600 mOsm/L) irrigation solution for routine medial femorotibial joint (MFTJ) arthroscopy. Primary outcomes included quantification of periarticular fluid retention based on measured changes in defined stifle joint girth and ultrasonographic (US) criteria. Water content of tissue samples was assessed. The viability of articular cartilage was determined using a microscopic fluorescent cell viability staining system.

RESULTS

No significant difference in postprocedural joint swelling was observed between LRS and HYPER treatment groups. Percent increments in femorotibial joint dimensions (mean ± SD) were seen in both treatment groups based on US (LRS, 83.9 ± 84.6%; HYPER, 131.2 ± 144.9%) and caliper measurements (LRS 5.5 ± 4.3%; HYPER 7.5 ± 5.8%) (P ≤ .05). Chondrocyte viability and tissue water content were maintained in both treatment groups, and differences were not statistically significant.

CLINICAL RELEVANCE

Doubling the osmolarity of an irrigation solution used routinely for arthroscopy does not result in detrimental effects on chondrocyte viability or tissue water content. However, use of a relatively HYPER irrigation solution did not attenuate procedural tissue swelling of the equine stifle joint.

Open access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association