Survival after Small Intestine Resection and Anastomosis in Horses

The authors examined factors influencing survival in 140 horses that recovered from anesthesia after small intestinal resection between 1968 and 1986, using Kaplan-Meier estimated survival curves and the Cox proportional hazards regression model. Seventy-two horses (51%) died during the initial postoperative period, 19 horses (14%) died after discharge from the hospital, 33 horses (24%) were alive, and 16 horses (11%) were classified as censored. Mean age at surgery was 8 years. Horses 15 years of age or older, Arabians and Stallions, were overrepresented in the hospital population. The most common reason for resection was strangulation of bowel through a mesenteric rent. The mean and 50% median survival times were 1540 and 27 days, respectively. Horses admitted after January 1, 1980, had a significantly longer survival than those admitted before that time. Survival was longer after anastomosis of two small intestinal segments than after anastomosis of a small intestinal segment to the cecum; however, the length of bowel resected and the method of anastomosis had no demonstrable influence on survival. Of the variables studied, the heart rates at presentation and 24 hours after surgery were the most accurate predictors of survival.     

Figurate Erythema Resembling Erythema Annulare Centrifugum in a Ferret with Adrenocortical Adenocarcinoma-associated Alopecia

Resumen— Describimos un caso de alopecia simétrica bilateral en un hurón hembra esterilizada de 3 años. El cuadro resultó estar asociado con un adenocarcinoma adrenocortical y con concentraciones séricas elevadas de estradiol. Además el animal presentaba eritema figurado en la zona dorsolateral, lumbosacra y en la cola con caracteristicas clinicas e histopatológicas parecidas al eritema annulare centrifugum de la especie humana. El eritema figurado se trató con éxito con un producto comercial que contiene el ácido graso omega-3/omega-6. [Scott D. W., Gould, J. W., Cayatte, S. M., Lawrence, H. J., Miller, W. H., Jr. Figurate erythema resembling erythema annulare centrifugum in a ferret with adrenocortical adenocar-cinoma-associated alopecia (Eritema figurado parecido a eritema anulare centrifugum en un hurón con alopecia asociada a un adenocarcinoma adrenocortical).
Abstract— Bilaterally symmetric alopecia and vulvar enlargement is reported in a 3-year-old, spayed female ferret. The condition was ultimately shown to be associated with an adrenocortical adenocarcinoma and elevated serum estradiol concentrations. In addition, the ferret had a figurate erythema over the dorsolateral lumbosacral region and tail that was clinically and histopathologically similar to erythema annulare centrifugum in humans. The figurate erythema was successfully treated with a commercial omega-3/omega-6 fatty acid-containing product.     

Evaluation of Propofol as a General Anesthetic for Horses

This study provides baseline information on the potential use of propofol as a general anesthetic for horses. Using a Latin square design, propofol (2, 4, and 8 mg/kg) was administered intravenously on three separate occasions to six mature horses. Information about anesthetic induction, duration, and recovery was recorded along with results of rectal temperature, heart rate, respiratory rate, pHa, Paco₂ and Pao₂. Statistical analysis included a mixed model analysis of variance, a general linear model analysis and least square means test for post hoc comparisons. A P <.05 was considered significant. The quality of induction of anesthesia varied from poor to good. Two horses were not recumbent following the lowest dose of propofol. Brief paddling limb movements occurred occasionally and unpredictably after recumbency induced by all three doses. During recovery, horses were uniformly calm and coordinated in their moves to stand. Duration of recumbency (minutes) was dose related; 15.05 ± 1.58 (±±SD) following 2 mg/kg, 31.06 ± 5.56 following 4 mg/kg, and 47.85 ± 13.63 following 8 mg/kg. During recumbency at all doses, heart rate significantly increased from a predrug value of 40 ± 6 beats per minute. Substantial respiratory depression, characterized by a significant decrease in respiratory rate (from 11.7 ± 2.9 to 3.7 ± 1.6 breaths per minute) and increased Paco₂ (from 44.5 ± 2.5 to 52.7 ± 8.0 mm Hg) was seen only after 8 mg/kg. A significant decrease in Pao₂ was observed throughout the recumbency induced by 8 mg/kg, and also at 3 and 5 minutes following induction of anesthesia with 4 mg/ kg propofol. At 5 minutes after injection, Pao₂ was 87.4 ± 13.8 and 58.1 ± 17.0 mm Hg after 4 and 8 mg/kg, respectively. The results of this study do not favor the routine use of propofol as a sole anesthetic in otherwise unmedicated horses.     

The effects of antigenic competition on the efficacy of multivalent footrot vaccines

SUMMARY A multivalent footrot vaccine has been developed, containing pilus antigens produced in recombinant Pseudomonas aeruginosa and representing all nine serogroups of Dichelobacter (Bacteroides) nodosus commonly recognised in the field. The responses of sheep to the multivalent vaccine have been compared with those to monovalent vaccines representing only a single serogroup. Antigenie competition between serogroups occurred in sheep immunised with the multivalent formulation, but high levels of protection were still achieved. The study showed that in multivalent footrot vaccines, antigenic competition is predominantly due to the presence of a family of immunologically-related pilus antigens rather than to interference by extraneous proteins.     

Pharmacokinetics of cephalexin in cats after oral administration of the antibiotic in tablet and paste preparations

Objective To determine the bioequivalence of a paste formulation of cephalexin with that of the tablet form.
Design A two-way cross-over study.
Animals Ten adult cats of mixed breed.
Procedure The cats, randomly allocated to two groups, received either the paste preparation or the tablet orally at 12-hour intervals for 48 h before a 12-hour blood collection period. Two weeks later the treatments were reversed and the blood sampling repeated. The serum concentrations of the antibiotic were determined. The pharmacokinetic factors were analysed using a computer.
Results There were no significant differences between the peak concentration of cephalexin, or the other pharmacokinetic factors obtained from the tablet and paste formulations. The serum profiles of cephalexin following four 12-hourly doses of each formulation were similar with the peak serum values occurring at approximately 2 h after administration.
Conclusion The paste formulation and the tablet form are bioequivalent.     

Evaluation of an Interfragmentary Compression System for the Repair of Equine Femoral Capital Physeal Fractures

Femoral neck and proximal epiphyseal lengths were measured in 37 femurs from 19 cadaver foals that were 1 day to 12 months old to determine the applicability of a human interfragmentary compression system to equine femoral capital physeal fractures. Because components of the implant system are available only in fixed sizes, its use was possible in foals older than 5 weeks of age, but not in younger foals. The 135 degree angle plate conformed best to the equine femur. Femoral capital physeal fractures were created surgically and repaired with the implant system in three foals. Fracture stability was evident clinically and radiographically in all three foals until euthanasia at month 3. At necropsy, the treated femurs were 4, 8, and 27 mm shorter than their mates. Epiphyseal viability was verified in all three foals by tetracycline deposition and new appositional bone growth comparable with that in the contralateral control epiphyses. The treated capital physis was open but reduced in thickness in one foal, disorganized in one foal, and closed in one foal. Fixation by compression with the implant system resulted in stability sufficient for fracture healing and maintenance of epiphyseal viability, although it was associated with reduced longitudinal femoral growth.     

Upper Airway Function during Maximal Exercise in Horses with Obstructive Upper Airway Lesions Effect of Surgical Treatment

Upper airway pressure was measured during maximal exercise in 10 Thoroughbred racehorses with naturally occurring upper airway obstruction. Left laryngeal hemiplegia and arytenoid chondropathy resulted in substantial increases (30-40 cm H2O) in inspiratory upper airway pressure (Pl), whereas complicated aryepiglottic entrapment and subepiglottic cysts produced only modest increases (15 cm H2O) in Pl. Uncomplicated aryepiglottic entrapment and grade IV pharyngeal lymphoid hyperplasia produced only slight increases (3-5 cm H2O). In general, surgical procedures restored airway pressures to within normal limits. Subtotal arytenoidectomy improved but did not normalize airway pressures in horses with arytenoid chondropathy. Pharyngeal lymphoid hyperplasia appeared to have little effect on upper airway function.     

Bilateral hypoplasia of the soft palate in a foal

Bilateral hypoplasia of the soft palate and aspiration pneumonia occurred in a Standardbred foal. The filly was presented with a history of illthrift, dyspnoea, coughing and bilateral nasal discharge. Abnormal sounds (crackels and wheezes) were auscultated over all lung fields and the cervical trachea. Endoscopy revealed a shortened soft palate with a uvula-like mass protruding from the free border into the nasopharynx. Mucopurulent material was present in the trachea. Samples obtained by tracheal wash were submitted for cytology, culture and sensitivity testing. Results indicated a septic inflammatory process. On lateral radiographs of the thorax there were patchy areas of consolidation and air bronchograms. The foal was euthanased. Necropsy confirmed the presence of a palatal defect and aspiration pneumonia of moderate severity. No other congenital abnormalities were present.     

Immunological detection of cardiac glycosides in plants

Summary Australian native and introduced plants were examined, using digoxin immunoassays, to detect the presence of cross-reacting cardiac glycosides. These compounds were found in 27 species from 20 genera. The assay technique can also be used on serum samples to confirm cardiac glycoside ingestion.     

Pharmacokinetics of gentamicin after intravenous and subcutaneous injection in obese cats

Six adult domestic shorthair obese cats were given 3-mg/kg gentamicin sulfate by rapid i.v. and by s.c. injection in a cross-over design. The plasma concentration-time data were analyzed using statistical moment theory with no assumption of a specific compartmental model. Means +/- SD for the half-life, which was calculated from the terminal slope of the log concentration-time curve, were 1.37 +/- 0.24 and 1.24 +/- 0.22 h following i.v. and s.c. injection, respectively. The apparent volume of distribution at steady state was 118.55 +/- 19.83 ml/kg, and total body clearance was 1.07 +/- 0.25 ml/kg/min. Bioavailability was 83.58 +/- 14.83% after s.c. administration. The calculated s.c. dose in obese cats to produce an average steady-state concentration of 4 micrograms/ml is 2.5 mg/kg every 8 h compared to 3 mg/kg in normal-weight cats.