Hypoglycemia alters pulsatile luteinizing hormone secretion in the postpartum beef cow

This study tested the hypothesis that the increased glucose requirement of lactation had effects that were independent of the suckling-dependent inhibition of postpartum endocrine function in beef cows. Mature Hereford cows were either suckled ad libitum and infused with saline iv (n = 9) from d 2 through 4 (d 0 = jugular catherization on d 32 +/- 3 postpartum); were nonsuckled and infused with saline from d 2 through 4 (n = 10); or were nonsuckled and infused with phlorizin (3 g/d) from d 2 through 4 (n = 10). Nonsuckled cows infused with phlorizin had lower (P less than .05) plasma concentrations of glucose and amino acid nitrogen (AAN) on d 2 compared with pre-infusion levels (d 1), but their metabolic profile returned to levels similar to the suckled cows by d 3 and 4. Nonsuckled cows infused with saline had elevated glucose and insulin and lower AAN and free fatty acids (FFA) on d 3 and 4 compared with pre-weaning (d 1) levels (P less than .05). Nonsuckled cows infused with phlorizin did not show this weaning-induced elevation in glucose and insulin. The number of luteinizing hormone (LH) pulses was not affected by treatment. However, in contrast to the large LH pulses observed in the nonsuckled cows infused with saline, both the suckled cows and the nonsuckled cows treated with phlorizin had more small and fewer large amplitude pulses (P less than .01). Treatment did not affect serum concentrations of follicle stimulating hormone, gonadotropin release in response to gonadotropin releasing hormone (25 micrograms) or the number of cows ovulating by 55 d after calving. We conclude that the increased glucose clearance caused by phlorizin infusion or lactation results in depression of LH pulse amplitude in suckled postpartum beef cows.     

Purification of the alpha toxin of Clostridium perfringens type A by ultrafiltration and gel chromatography

Clostridium perfringens type A toxin produced in Jayko & Lichstein medium was subjected to various concentration and purification procedures. The results obtained with 3 different ultrafiltration membranes followed by gel filtration showed that by using Millipore PSED OHV10 and Amicon XM-100 filter membranes in combination, a three-hundred-and-fivefold purification could be achieved as against a twelvefold increase obtained with ammonium sulphate/acetone precipitation. The lecitovitelin test was more sensitive than the haemolytic activity in determining the alpha toxin activity. The optical density, measured at 280 nm, did not reveal any alpha toxin activity in the relevant toxic fractions.     

Total hip replacement

Total hip replacement in the dog has proved to be a highly successful method of restoring normal, pain-free motion to the coxofemoral joint. In a prospective study done at The Ohio State University College of Veterinary Medicine and the Berwyn Veterinary Associates Hospital, the indications and contraindications, the most effective surgical technique, the complication rate, and the long-term functional evaluation have been established for canine total hip replacements. This study has established that a 95 per cent success rate for function of the hip joint can be achieved if the established guidelines are followed.     

Persistence of colonies of Anaplasma marginale in overwintering Dermacentor variabilis

Dermacentor variabilis were infected as nymphs with Anaplasma marginale by allowing the ticks to feed on a single infected donor calf. Two weeks after molting to the adult stage, the ticks were allotted into 1 of 3 groups and were allowed to overwinter at room temperature (25 C) in the laboratory (group 1), cold storage (4.5 C) in the laboratory (group 2), or outdoors in leaf litter (group 3). Persistence of A marginale was assessed by determining density of colonies (number of colonies/0.1 mm2 of gut tissue examined) in tick gut specimens at 3, 5, 7, 9, and 12 months after molting to the adult stage. Colonies of A marginale were found in all groups at every density evaluation period. Highest colony densities were observed uniformly in specimens collected at month 7 (May); densities decreased at month 9 and were lowest at month 12. Statistical analysis indicated that ticks subjected to cold storage and to outdoor conditions had similar colony densities of A marginale; the density curve in these 2 groups indicated significant quadratic effects over time, with peak densities in May. Mean colony density in ticks kept at room temperature fit a different quadratic equation. The morphologic data indicated that A marginale overwinters in Dermacentor variabilis, and that increasing numbers of organisms are found from January to May.     

Techniques for venous blood sampling from the white pekin duck

Common sites for blood sampling in the pekin duck and other avian species include the basilic vein, jugular vein, superficial plantar metatarsal vein, heart, and occipital sinus. The use of each of these sites is described and/or illustrated. In the present study using the pekin duck, the superficial plantar metatarsal vein proved most satisfactory for collecting repeated samples (every 5 minutes for 30 minutes) with minimal trauma to the duck.     

Haematogenous osteomyelitis in cattle

The examination of 70 cattle with haematogenous osteomyelitis resulted in the classification of the bone lesions into two main groups: the physeal type, in which an infection, usually of metaphyseal bone, originated at or near the growth plate, usually in the distal metacarpus, metatarsus, radius or tibia, and the epiphyseal type, in which an infection originated near the junction of the subchondral bone and the immature epiphyseal joint cartilage, most often in the distal femoral condyle epiphysis, the patella and the distal radius. Combinations of physeal and epiphyseal defects and even diaphyseal involvement were occasionally seen. Epiphyseal osteomyelitis was mostly caused by salmonella infection, physeal by Corynebacterium pyogenes, salmonella and other bacteria. The salmonella affected animals were with one exception less than 12 weeks old and the majority had had some previous illness or came from a problem herd. The C pyogenes affected calves were in almost all cases more than six months old. The prognosis of the metaphyseal infection was in general satisfactory, and surgical intervention (osteotomy or sequestrectomy) was often required. The prognosis of the epiphyseal type was grave but two of the three animals in which physeal and epiphyseal defects were accompanied by diaphyseal lesions recovered.     

Comparison of various treatments for experimentally induced equine infectious arthritis

To evaluate the effects of 5 treatments on clinical responses, synovial fluid analysis, radiographic changes, bacteriologic culture results of the synovial fluid and synovial membrane, microscopic characteristics of the synovial membrane, and articular cartilage histochemistry, Staphylococcus aureus organisms (1.6 X 10(6) colony-forming units) were inoculated into the tarsocrural joints of 12 horses (n = 24 joints; 2 joints/horse). Each horse was given phenylbutazone (2 g) orally, every 24 hours, beginning 24 hours after inoculation. Two horses (ie, 4 joints) were not given other treatment (controls; group 1). All other horses (ie, 20 joints) were given a trimethoprim-sulfadiazine combination orally, once daily (30 mg/kg; 8 joints) or twice daily (30 mg/kg q 12 hr; 12 joints). Each of these 20 joints were assigned to 1 of 5 treatment groups (4 joints/group) in a balanced incomplete block design. Group 2 (4 joints) was given only the antibiotics once daily. Twelve joints were treated by through-and-through joint lavage on day 1 (group 3), days 1 and 3 (group 4), or days 1, 3, and 6 (group 5). Joints in group 6 had an arthrotomy performed on day 1, with subsequent lavage via an indwelling drain every 12 hours for 4 days. In groups 3 through 6, 1 joint in each group was treated with antibiotics once daily, and 3 joints were treated with antibiotics twice daily. All horses were clinically assessed each day. Complete blood count was performed on days 3, 6, 10, and 21. Before inoculation and on days 0, 1, 3, 6, 10, and 21, synovial fluid specimens were collected and analyzed for color, clarity, total protein concentration, WBC count, differential count, and mucin clot-forming ability. Synovial fluid specimens were cultured bacteriologically before inoculation and on days 0 and 21. Horses in group 1 (controls) were euthanatized before day 6. All other horses were euthanatized on day 21. Tarsocrural joints were opened and examined. Synovial membrane specimens were bacteriologically cultured. Synovial membrane specimens were examined histologically (hemotoxylin and eosin stain) and articular cartilage specimens were (safranin O fast green stain) evaluated histochemically. Synovial membrane specimens were histologically graded into 5 categories. Intensity of articular cartilage intercellular staining with safranin 0 was graded for superficial, outer intermediate, inner intermediate, and deep zones. Two-way analysis of variance was performed to evaluate differences among groups and across time for the determinants evaluated.(ABSTRACT TRUNCATED AT 400 WORDS)     

Cardiovascular effects of intermittent or continuous treadmill conditioning in horses

Nine mature Quarter Horse mares were trained for ten weeks by continuous (n=4) or intermittent (n=5) treadmill work. Both groups of horses trotted at 3.3m/sec. The continuous work was performed at a 3% incline while the intermittent work was done at a 9% incline. Heart rate, cardiac output and blood lactate concentration were measured during a standard exercise test that included work on both treadmill grades before and after five and ten weeks of training. The two conditioning programs did not produce differences in the measured parameters of the two groups of horses. However, there was an overall conditioning effect observed in both groups of horses throughout the ten weeks of treadmill conditioning. Heart rate decreased (P<.05) during exercise on both treadmill grades after ten weeks of training. Lactate concentration decreased (P<.05) during the 9 percent grade trot after five weeks of training. Only slight further decreases occurred between week five and week ten of conditioning. Cardiac output increased (P<.05) between rest and exercise on both grades but there was no conditioning effect.     

Clinicopathological findings associated with feline infectious peritonitis in Sydney, Australia: 42 cases (1990-2002)

Objectives To review the clinicopathological findings in naturally-occurring, histopathologically confirmed cases of feline infectious peritonitis in client-owned cats in Sydney, Australia, with the purpose of identifying factors assisting in the diagnosis of this complex disease syndrome and to characterise the disease as it occurs in this region.
Design Retrospective clinical study: the clinical records of all cats with histopathologically confirmed feline infectious peritonitis at the University Veterinary Centre Sydney and a private cat hospital in Sydney between 1990 and 2002 were reviewed for signalment, history, physical findings, diagnostic test results and the distribution of histological lesions throughout the body at necropsy.
Results Forty-two cats met the inclusion criteria. Significant features of this study that unique to the contemporary literature are i) the over-representation of certain breeds (Burmese, Australian Mist, British Shorthaired, and Cornish Rex) and the under-representation of other breeds (Domestic Shorthaired, Persian); ii) the overrepresentation of males; iii) the tendency for effusive disease in Australian Mist cats and non-effusive disease in Burmese; iv) the even age distribution of disease seen in cats older than 2 years-of-age; and v) the presence of fulminant immune-mediated haemolytic anaemia in two cats in this study.
Conclusion The study highlights the diverse range of clinical manifestations and the complexities experienced by clinicians in diagnosing this fatal disease. Some aspects of the epidemiology and clinical manifestations of feline infectious peritonitis appear different to the disease encountered in Europe and North America, most notably the over-representation of specific breeds and the presence of immune-mediated haemolytic anaemia.