Mammary neoplasia in the guinea pig (Cavia porcellus).

Mammary tumors are reported in four guinea pigs and the literature is reviewed. It is concluded that mammary adenocarcinomas are second only to pulmonary adenomas as the most common epithelial tumors in the guinea pig. The sex incidence of mammary tumors is almost equal and both young and old animals are susceptible. Mammary tumors are generally locally invasive, rarely metastasize, are often quite large, and very vascular. Surgical excision of mammary tumors is possible but recurrence should be expected if the primary tumor is incompletely removed.     

Factors affecting the incidence of pneumonia in growing bulls.

The occurrence of respiratory disease at two Meat and Livestock Commission bull performance test centres over a period of three years is assessed. During this period a change in the system of testing was introduced so as to allow younger bulls to enter the centre and also to increase their throughput. This resulted in an increase in the incidence of pneumonia of more than five times. The management at one centre was changed to counteract this disease problem and the level of pneumonia was greatly reduced. Most respiratory disease occurred within the first month of entry to the centres. There was more infection during the second half of the year and especially in the October to December quarter. There appeared to be some relationship between the time bulls were weaned prior to entry to the centres and the incidence of pneumonia.     

Primary hemangiosarcoma of the iliopsoas muscle eliciting a peripheral neuropathy

An eight-year-old, male castrated bullmastiff presented to the Kansas State University Veterinary Medical Teaching Hospital with left hind-limb paralysis. A mass was identified in the left paralumbar soft tissue adjacent to the fourth (L4) to sixth (L6) lumbar vertebrae by magnetic resonance imaging. The iliopsoas muscle contained the mass which was identified as a hemangiosarcoma on histopathological examination. Hemangiosarcoma is rarely reported as a primary tumor arising from muscle vascular endothelium.     

Effects of modified tall oil and creatine monohydrate on growth performance, carcass characteristics, and meat quality of growing-finishing pigs

The effects of feeding modified tall oil (MTO) and creatine monohydrate (CMH) on growing-finishing pig growth performance, carcass characteristics, and meat quality were determined. Eighty cross-bred barrows (initially 45.4 kg) were allotted randomly to one of four dietary treatments by weight and ancestry. The experiment was arranged as a 2 x 2 factorial with two levels of MTO (0 or 0.50%), which were fed throughout the growing-finishing period, and two levels of CMH (0 or 25 g/d), which were fed for the final 10 d before slaughter. The corn-soybean meal diets were fed in two phases (45.4 to 78.9 kg and 78.9 to 117.5 kg BW). When CMH was added to the diet in place of corn, average BW was 107.5 kg. Feeding MTO increased (P < 0.05) ADG and gain:feed ratio (G/F) during the 45.4- to 78.9-kg growth interval and tended to improve (P = 0.10) G/F during the 45.4- to 107.5-kg growth interval. Dietary treatment did not affect (P > 0.15) growth performance during the 78.9- to 107.5-kg growth interval. Modified tall oil increased (P = 0.02) G/F during the 10-d CMH supplementation period, and CMH numerically (P = 0.11) increased ADG and G/F. Supplementation of CMH did not affect (P > 0.20) any measured carcass characteristic or measures of meat quality at 24 h or 14 d postmortem. Feeding MTO reduced average back-fat (P = 0.05) and 10th rib backfat (P = 0.01) but did not affect (P > 0.10) other measured carcass characteristics or measures of meat quality at 24 h postmortem. Modified tall oil increased (P = 0.02) L* values (lightness) and tended to increase (P < 0.10) thawing and cooking losses of longissimus muscle chops at 14 d postmortem. These data demonstrate that MTO improves growth performance and reduces backfat in growing-finishing pigs, but supplementation of CMH, under the conditions of this experiment, was not beneficial for growing-finishing pigs.     

Actions and interactions of ADP, 5- HT, histamine and PAF on equine platelets

Platelets are thought to play a role in equine diseases such as acute laminitis and verminous arteritis and may be involved in allergic disease. Mediators implicated in the pathophysiology of these conditions activate platelets and responses may be enhanced by interactions between mediators. The present study compared platelet aggregation, thromboxane production and release of radiolabelled [(3)H]5- HT in response to 5- HT, histamine, ADP and PAF alone and in combination in vitro.PAF caused concentration-related aggregation, [(3)H]5- HT release and thromboxane production. In contrast, ADP caused aggregation and 5- HT induced the release of [(3)H]5- HT with little effect on other platelet functions. Histamine had little or no effect on equine platelets. Addition of 5- HT (10 microM) prior to ADP significantly displaced the aggregation response curve to the left.The profile of responses to PAF, ADP and 5- HT suggests differential activation of intracellular signalling pathways regulating these events. The enhanced response to ADP in the presence of 5- HT may have implications in thromboembolic disease in the horse.