Effects of a proprietary topical medication on wound healing and collagen deposition in horses.

Full-thickness skin wounds were created on the dorsum of both metacarpi in 8 horses. Three topical treatment regimens were studied. All wounds were bandaged with a nonadherent dressing, which was held in place with a snug elastic wrap. Group-A wounds were treated with a proprietary topical wound medication that consisted of a spray and an ointment. Group-B wounds were treated with the same regimen, except the putative active ingredients in the ointment were omitted. Group-C wounds were treated with a dry nonadherent bandage only. Wound dressings were changed every day and the limbs were photographed every other day until the wounds were healed. Specimens of normal skin and biopsy specimens of healed wounds were examined histologically and were assayed for hydroxyproline content. Wound healing measurements quantitated for each wound were number of days to healing, maximal wound size attained, day wound contraction commenced, day epithelium first noticed, rate of wound contraction, final wound size, and fraction of the wound that healed by contraction. The cosmetic appearance of the healed wounds was also graded. Significant differences were not noticed in hydroxyproline content, histologic appearance, or any of the wound healing measurements between treatment groups. The cosmetic appearance of healed group-A and -B wounds was significantly better than the appearance of group-C wounds. The topical treatment regimens studied neither enhanced nor inhibited wound healing in this study.

In vitro transport of L-alanine by equine cecal mucosa.

When sheets of mucosa from the cecum of clinically normal horses were incubated in vitro with radiolabeled L-alanine, they could accumulate this amino acid against an apparent concentration gradient after 60 to 150 minutes of incubation. The active transport system for L-alanine was on the serosal surface of the mucosal sheet only. L-Alanine accumulation at 60 minutes was partly inhibited by 20 mM glycine (P less than 0.01), 0.5 mM ouabain (P less than 0.05), and Na deprivation (P less than 0.02). Anoxia for 60 minutes increased L-alanine accumulation, but had adverse effects on cell structure and intracellular cation distributions. Transmucosal fluxes induced a small, but significant (P less than 0.05), net secretion of L-alanine, and the mean (+/- SEM) transmucosal potential difference was 7.3 +/- 0.7 mV over the period of flux measurement. It was concluded that L-alanine was accumulated by the serosal surface of the cecal mucosa, possibly to provide substrate for tissue metabolism. There was no evidence that the cecal mucosa could actively transport this amino acid from the luminal bathing medium.

Intestinal decompression: preliminary study in the horse.

A technique of nasoduodenal (N-D) intubation and intestinal decompression was developed and used in the horse to explore the prevention of gastric and intestinal distention after abdominal surgical operation. Three styles of tubes (2 single-lumen tubes and 1 double-lumen tube) were positioned in the duodenum of 12 mature horses (10 experimental and 2 clinical) during laparotomy (without enterotomy), and an iatrogenic occlusion at the small intestine was created and later released in the 10 experimental horses. The 2 clinical horses had an exploratory laparotomy to correct a natural obstruction of the small intestine. After each horse recovered from surgical manipulation, suction was used to keep fluids from accumulating in the cranial part of the gastrointestinal tract. In 5 of the 12 horses, the most simple N-D tube was positioned successfully and functioned properly. Three of the 5 horses which were fasted before surgical manipulation (to obtain an empty stomach) survived without postsurgical complications. Volume of reflux material was measured. Clinical data, such as periods of comfort during decompression without giving analgesics, were recorded. Necropsies were done on 10 of the 12 horses (9 experimental and 1 clinical). Although already tested in 2 clinical horses, use of the N-D tube remains experimental, and the N-D tube functioned only in horses which were fasted before surgical manipulation. Perfection of a safe and dependable means of emptying the equine stomach of its solid ingesta before gastrointestinal intubation is done, is the next step in affording greater clinical application of the N-D tube for gastrointestinal decompression.