Risk factors for reduced postoperative fecal output in horses: 37 cases (1997-1998)

OBJECTIVE: To determine prevalence and risk factors for development of ileus of the large intestine after surgery in horses, identified by reduced postoperative fecal output (RPFO). DESIGN: Retrospective study. ANIMALS: 37 horses that developed RPFO after undergoing general anesthesia for reasons unrelated to the gastrointestinal tract. PROCEDURE: Fecal output was obtained from medical records as number of defecations per 24-hour period after surgery; RPFO was defined as < or = 3 defecations per 24-hour period after surgery. The reference population included 48 horses that defecated > or = 4 times during the same period. Demographic, clinical, and surgical variables were evaluated for their association with development of RPFO by use of logistic regression analysis. RESULTS: Ten (12%) horses, all of which had RPFO, developed signs of colic after surgery. Horses > or = 5 years old that underwent orthopedic procedures of > 60 minutes' duration and that did not receive phenylbutazone after surgery were at significant risk for developing RPFO. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that after surgery unrelated to the gastrointestinal tract in horses, there is an intermediate clinical phase characterized by reduced fecal output preceding overt signs of colic. Recognition of RPFO may reduce morbidity and mortality of such horses.     

Deep digital flexor tenotomy for treatment of severe laminitis in a cow

A first-calf Guernsey cow was referred for evaluation of severe udder edema, mastitis, metritis, and ketosis. During the course of treatment, the cow became recumbent and was unable to rise. Intensive treatment resulted in the cow being able to stand for short periods with the aid of a sling. However, severe pressure necrosis of the udder and ongoing mastitis made performance of a complete mastectomy necessary. After surgery, the cow's condition improved, although assistance in standing was still required. Radiography of the distal phalanges revealed severe rotation in the right lateral and left medial digits of the hind limbs. The laminitis was nonresponsive to medical management; therefore, a deep digital flexor tenotomy was performed in the affected claws. The procedure provided almost immediate relief of signs of foot pain and resulted in ability to stand without assistance. Deep digital flexor tenotomy should be considered when treating cows with severe laminitis.     

Reference values of the brainstem auditory evoked response of methoxyflurane anesthetized and unanesthetized dogs

The brainstem auditory evoked response (BAER) was recorded from 7 unanesthetized and 27 methoxyflurane anesthetized dogs. A 0.1 msec, 70 dB stimulus delivered at 10 Hz evoked the expected seven wave BAER. Mean peak wave latencies and standard deviations were calculated. Differences were not found between neither right and left ears, nor male and female dogs. The anesthetized dogs had a significantly longer latency for all waves, except wave I, than the unanesthetized dogs. Use of the BAER as a diagnostic technique for brainstem lesions is recommended.Publication No. 1702, School of Veterinary Medicine, Auburn University, AL 36849, USA     

The use of antibiotics on small dairy farms in rural Peru

Very little is known about the use of antibiotics on small dairy farms in lower/middle-income countries. The use of these drugs can have profound impacts on animal health, farmer income and public health. A survey of 156 farmers was conducted in Cajamarca, a major dairy-producing center in the highlands of Peru characterized by small farms (<15 cows) to assess patterns and determinants of antibiotic use and farmers’ knowledge of antibiotics. The reported incidence of disease on these farms was relatively low (0.571 episodes of disease per cow-year), but more than 83% of the reported episodes were treated with antibiotics. The most commonly used antibiotics were oxytetracycline, penicillin and trimethoprim-sulfamethoxazole drugs; antiparasitic drugs were also used to treat what were likely bacterial infections. An increased incidence of treated disease was significantly associated with smaller farm size, lower farmer income, the previous use of the Californian Mastitis test on the farm and antibiotic knowledge. Farmers’ knowledge of antibiotics was assessed with a series of questions on antibiotics, resulting in a “knowledge score”. Increased knowledge was significantly associated with the use of antibiotics for preventative reasons, the purchase of antibiotics from feed-stores, the experience of complications in animals after having administered antibiotics, the number of workers on the farm and the educational level of the farmer. Overall, antibiotics appeared to be used infrequently, most likely because therapeutic interventions were sought only when the animal had reached an advanced stage of clinical disease. Few farmers were able to define an antibiotic, but many farmers understood that the use of antibiotics carried inherent risks to their animals and potentially to the consumers of dairy products from treated animals. The results of this study are useful for understanding the patterns of antibiotic use and associated management, demographic and knowledge factors of farmers on small dairy farms in rural Peru.     

Soil sorption–desorption of phosphorus from piggery effluent compared with inorganic sources

The leaching of phosphorus (P) within soils can be a limiting consideration for the sustainable operation of intensive livestock enterprises. Sorption curves are widely used to assist estimation of P retention, though the effect of effluent constituents on their accuracy is not well understood. We conducted a series of P‐sorption–desorption batch experiments with an Oxic Haplustalf (soil 1), Haplusterts (soils 2 and 3), and a Natrustalf (soil 4). Phosphorus sources included effluent, orthophosphate‐P in a matrix replicating the effluent's salt constituents (the reference solution), and an orthophosphate‐P solution. Treated soils were incubated for up to 193 days before sequential desorption extraction. Effluent constituents, probably the organic or particulate components, temporarily increased the vulnerability of sorbed‐P to desorption. The increase in vulnerability was removed by 2–113 days of incubation (25°C). Despite vigorous extraction for 20 consecutive days, some P sorbed as part of the treatments of soils 1 and 2 was not desorbed. The increased vulnerability due to effluent constituents lasted a maximum of about one cropping season and, for all other treatments, adsorption curves overestimated vulnerability to desorption. Therefore, adsorption curves provide a conservative estimate of vulnerability to desorption where effluent is used in continued crop production in these soils.     

Gonadotropin-releasing hormone: one polypeptide regulates secretion of luteinizing and follicle-stimulating hormones

A polypeptide isolated from porcine hypothalami stimulates the release of both luteinizing hormone and follicle-stimulating hormone from the pituitaries of several species. This polypeptide has been structurally identified as (pyro)Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH(2) and synthesized. The natural and synthetic materials share biological properties. It appears that this peptide represents the hypothalamic hormone regulating the secretion of both luteinizing hormone and follicle-stimulating hormone.