RENAL AND HEPATIC ULTRASONOGRAPHY IN THE NEONATAL DOG

The ultrasonographic appearance and size of the liver and kidneys of a litter of five pups was examined from birth until six months of age, and compared with a group of five adults of the same breed. Increased renal cortical echogenicity was evident for the first two weeks of life. Up to 12 weeks of age renal size was relatively large in comparison with body size parameters. After 12 weeks measures of renal size were proportionate with body size and were not significantly different from adult dogs. The neonatal liver had a similar ultrasonographic appearance to the adult, although in the first eight weeks parenchymal echogenic stippling was less coarse and portal veins were less well delineated. Measures of hepatic length were inaccurate during the first four weeks after birth due to changes in body conformation. From eight weeks to six months of age these measures were proportionate with body size, although the ratios differed from adult dogs.     

Reproduction in female cattle in a communal farming area of Zimbabwe

Summary Cattle in a communal farming area of Zimbabwe were identified and examined in the late dry and mid wet season of 1985/86. Ovarian activity rates were 17·9% and 38·6% in the dry and wet season respectively. Pregnancy rates were 16·1% and 24·6% respectively. A major limitation to reproduction was the percentage of anoestrous females. There was no evidence of a seasonal calving pattern. Median body condition score was 2·0 in the dry season and 1·5 in the wet season. Adult females of body condition score 2·5 and above had ovarian activity rates of 41·9% and pregnancy rates of 41·9 per cent. Those with a body condition score below 2·5 had rates of 26·8% and 16·4% respectively. Serum progesterone levels in pregnant animals were positively related to body condition score, with some animals having progesterone levels similar to non-pregnant animals. Metabolic profiles suggested that the major limiting nutrient in both seasons was nitrogen, although other micronutrients might also be involved in low reproductive rates.

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Resumen Se identificó un grupo de ganado en un área comunal pastoril en Zimbabwe, el que se estudió al final de la estación seca y en la mitad de la estación lluviosa. El estudio se llevó a cabo de 1985 a 1986. La tasas de actividad ovárica fueron de 17·9% y 38·6% y las de pre?ez de 16·1% y 24·6%, en la estación seca y lluviosa, respectivamente. La mayor limitación para la reproducción, fue el porcentaje alto de hembras en anestro. No hubo un patrón claro de partos estacionales. La condición corporal media fue de 2·0 en la estación seca y de 1·5 en la estación lluviosa. Las hembras adultas que tenian una condición corporal de 2·5 ó mayor, tuvieron tasas de actividad ovárica de 41·9% y tasas de pre?ez de 41·9 por vaca. Aquellas con una condición corporal por debajo de 2·5, tuvieron tasas de actividad ovárica de 26·8% y tasas de pre?ez de 16·4%, respectivamente. Los niveles de progesterona en animales pre?ados, estuvieron positivamente relacionados con el puntaje obtenido en el análisis de la condición corporal, aunque algunos animales tuvieron niveles de progesterona bajos, como de animales no pre?ados. Los perfiles matabólicos revelaron, que el nutriente más deficitario fue el nitrógeno, aunque otros nutrientes tambien fueron deficitarios.

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Résumé Dans une zone agricole de type communautaire, le bétail a été identifié et examiné à la fin de la saison humide et jusqu’au milieu de la saison sèche en 1985/1986. Les taux d’activité ovarienne étaient respectivement de 17,9 et 38,6 p. 100 au cours de la saison sèche et de la saison humide. Les taux de gestation étaient de 16,1 et 24,6 p. 100 respectivement. Un obstacle essentiel à la reproduction s’est révélé être le nombre de femmelles en anoestrus. Aucune preuve n’a pu être apportée d’un mode de mise bas lié à la saison. L’indice de condition corporelle moyenne mesuré à l’aide d’une échelle de points était de 2,0 en saison sèche et de 1,5 en saison humide. Les femelles adultes dont la condition corporelle était de 2,5 et au dessus, avaient des taux d’activité ovarienne de 41,9 p. 100 et des taux de gestation par co?t identiques. Celles dont l’indice était inférieur à 2,5 avaient des taux de 26,8 et de 16,4 p. 100 respectivement. Les taux de progestérone sérique chez les animaux en gestation étaient positivement liés à l’indice de condition corporelle, avec quelques sujets dont le taux de progestérone était identique à celui d’animaux non-gestants. Les profils métaboliques font penser que le facteur alimentaire limitant majeur pour les deux saisons était l’azote, quoique d’autres micronutriments aient pu être également en cause dans les taux de reproduction bas.

     

Idiopathic, aseptic, effusive, fibrinous, nonconstrictive pericarditis with tamponade in a standardbred filly.

A Standardbred filly was admitted for evaluation of pleuritis and pneumonia. Heart rate was 80 to 120 beats/min, and the pulse was barely palpable. Thoracic and abdominal ultrasonography and echocardiography revealed substantial pericardial effusion with cardiac tamponade, fibrinous pericarditis, pleural effusion, and ascites. Initial electrocardiography revealed normal sinus rhythm with decreased amplitude of the QRS complexes consistent with pericardial effusion. Following thoracentesis, echocardiogram-guided pericardiocentesis was performed. Bacterial culture yielded no growth from any of the fluids, and bacteria were not seen on cytologic examination. Initial treatment included broad-spectrum antibiotic treatments, IV fluid therapy, and anti-inflammatory agent administration. On the basis of negative culture results, an immune-mediated cause was considered, and dexamethasone was instituted in a decreasing dosage regimen. Pericardial effusion, ventral edema, and ascites began to resolve within 3 days after beginning dexamethasone treatment. Thirty days following discharge, the filly was reexamined, and at that time, the prognosis for athletic performance was considered good so the horse was returned to race training. The final diagnosis in this case was idiopathic, effusive, nonconstrictive pericarditis with tamponade. Early identification, clinical understanding, and application of knowledge of the pathophysiologic mechanisms of pericarditis in horses, combined with use of diagnostic aids such as ultrasonography and aggressive therapy consisting of effusion drainage, pericardial lavage, antibiotics that penetrate the pericardium, and corticosteroids when indicated are critical for a successful outcome in horses with pericarditis.     

Flow cytometric analysis of T cell response in mice infected with Cowdria ruminantium.

A 3-fold increase in the numbers of Lyt-2+ T cells in the circulating blood of mice infected and re-infected with the Welgevonden stock of Cowdria ruminantium, as determined by flow cytometry, is supportive evidence that immunity in heartwater is cell-mediated. The rise in Lyt-2+ cells only after re-infection of the mice is further evidence that the development of immunity in heartwater is dependent on the unhindered and adequate replication of C. ruminantium.     

The effect of dexamethasone-induced immunosuppression on the development of faecal antibody and recovery from and resistance to rotavirus infection.

Rotavirus-naive and rotavirus-immune gnotobiotic calves were treated with high doses of dexamethasone (DX) to suppress the immune system. Calves were then infected with a virulent rotavirus inoculum, J-160, to investigate the role of immune responses both in recovery from primary rotavirus infection and in resistance to secondary rotavirus infection. Treatment of calves with DX markedly suppressed in vitro responsiveness of peripheral blood lymphocytes to mitogens within 48 h of the start of DX treatment. Suppression was similar in rotavirus-naive and rotavirus-immune calves. In contrast, the effect of DX treatment on specific antibody responses differed depending on when DX treatment started in relation to rotavirus infection. When DX treatment commenced prior to primary rotavirus infection both systemic and local specific antibody responses were inhibited. These calves, in which mitogen and antibody responses were suppressed, exhibited greater clinical signs than did control calves after infection with virulent rotavirus, but virus excretion was affected in only one of the two calves. When DX treatment was started after primary rotavirus infection but before secondary infection, systemic and local antibody responses to the primary infection and to the challenge infection were not affected. These calves resisted challenge with virulent virus as did DX-untreated rotavirus-immune calves, even though mitogen responses were suppressed. We conclude that in a primary rotavirus infection, virus excretion ceased when both antibody and mitogen responses were suppressed. Resistance to secondary rotavirus infection occurred when mitogen responsiveness was suppressed, but when antibody levels were normal. Thus, no evidence was obtained that fully functional cell-mediated immune mechanisms are essential for resistance to rotavirus infection. Evidence was provided for the ability of parenteral treatment with DX to suppress mucosal as well as systemic antibody responses.     

Synchronization of estrus in dairy goats given norgestomet and estradiol valerate at various stages of the estrous cycle.

Dairy goats were given subcutaneous implants with 3 mg of norgestomet (NOR) and IM injections of 0.625 mg of estradiol valerate and 0.375 mg of norgestomet on day 0 of the estrous cycle (estrus; NOR 0, n = 18), on postestrus day 4 (NOR 4, n = 18), or on postestrus day 11 (NOR 11, n = 15). Ear implants were removed after 9 days. Mean (+/- SE) hours from removal of ear implants to onset of estrus and proportion of goats responding were 36 +/- 3.8 and 83%, 33 +/- 4.0 and 61%, and 36 +/- 2.7 and 93% for groups NOR 0, NOR 4, and NOR 11, respectively. There were no significant differences between treatment groups in time to onset of estrus. The percentage of goats in group NOR 11 that had signs of estrus was significantly greater than the percentage of goats in group NOR 4. Of the goats in groups NOR 0, NOR 4, and NOR 11 that had signs of estrus, 53, 55, and 86%, respectively, had onset of behavioral estrus between 24 and 48 hours after implant removal. All goats that had signs of estrus had onset of behavioral estrus between 12 and 72 hours after implant removal. Mean (+/- SE) hours from removal of ear implants to time of peak concentrations of luteinizing hormone (LH) were 49 +/- 4.1, 49 +/- 3.8, and 49 +/- 4.0 for groups NOR 0, NOR 4, NOR 11, respectively (not different). The percentage of goats in group NOR 11 that had LH peaks was significantly greater than the percentage of goats in group NOR 4.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of protein and energy supplementation of wheat straw-based diets on site of nutrient digestion and nitrogen metabolism of lambs.

A 4 x 4 Latin square metabolism trial with 2 x 2 factorial arrangement of treatments was conducted with lambs to determine effects of energy and CP supplementation of wheat straw-based (WS) diets on apparent N digestion, retention, and flow to the abomasum. Four wether lambs (average weight, 32 kg) fitted with ruminal and abomasal cannulas were fed 70 vs 42% WS (remainder of the diet was concentrate) and 9.5 vs 12.5% CP. Ruminal and total tract DM and OM digestion was 41 and 33% greater (P less than .03) for high-energy than for low-energy diets. Apparent N digestibility was greater (P less than .05) for 12.5% CP than for 9.5% CP diets (69.2 vs 62.0%, respectively) and also greater (P less than .03) for high-energy than for low-energy diets (67.4 vs 63.7%, respectively). High-energy diets resulted in a 23% greater (P less than .03) N retention (percentage of N intake) than did low-energy diets; 12.5% CP diets resulted in a 9% greater N retention (P less than .10) than did 9.5% CP diets. Nitrogen retention (percentage of N digested) was 15% higher (P less than .03) for high-energy than for low-energy diets. Protein level had no effect (P greater than .10). Nitrogen retention (grams/day) was 5.65, 6.97, 5.28, and 7.43 for low-energy, high-energy, low-protein, and high-protein diets, respectively; there were responses to energy level (P less than .03) and protein level (P less than .05). Total N flow (grams/day) to the abomasum did not differ (P greater than .10) due to treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Oscillating potentials on the B-wave of the ERG in the dog]

The oscillatory potentials (OP) on the b-wave of the canine ERG are characterized. Normal values for an OP-index, implicit times and periodicity are given. The OP-index increases during dark adaptation as well as with increasing stimulus intensities for white light flashes. Scotopic blue and red stimuli, although balanced for the maximum b-wave amplitude, surprisingly result in higher OP-indices for red flashes. Implicit times decrease for all OP with increasing stimulus intensities. Scotopic balanced red light results in OP with markedly reduced implicit times compared to blue light stimulation. The intervals between two OPs remain constant during dark adaptation, however, intervals between OPs with longer implicit times tend to be shorter. In contrast, the b-waves for scotopic balanced stimuli show rhythmic oscillations with constant intervals between them, the intervals being shorter for blue light than for red light. The intervals between OPs tend to become shorter with increasing stimulus intensities. This investigation indicates that OPs are influenced but not generated by photoreceptors. The examination of a dog with optic nerve hypoplasia indicates that the ganglion cells do not contribute to the biogenesis of OPs. The prognostic value of OPs in the early diagnosis for hereditary retinal degenerations in the dog is discussed.