SOME ECONOMIC ASPECTS OF THE APPLICATION OF PHOSPHATES TO PERMANENT PASTURES IN IRELAND

During the years 1957 to 1959 a number of trials carried out at various centres throughout the country showed that the yield of Irish pastures could be greatly increased through the application of fertilizers. Phosphorus increased both yield and the protein content of herbage. The increase in yield was a linear function of the initial P status of the herbage. For the series as a whole, phosphorus increased the yield by approximately 20%, potassium by 7% and phosphorus and nitrogen by 45%. The national and sociological implications of these results are discussed.     

Paratuberculosis in cattle: a comparison of three serologic tests with results of fecal culture

Feces and blood were collected from cattle in 13 herds known to be infected with Mycobacterium paratuberculosis to evaluate a complement-fixation (CF) test, an agar gel immunodiffusion (AGID) test and an enzyme-linked immunosorbent assay (ELISA) for the serologic diagnosis of paratuberculosis. M. paratuberculosis was isolated from the feces of 36 of 192 cattle examined. Twenty-three culture-positive animals had CF test titers regarded as suspect or positive, 10 were positive by the AGID test and 34 were suspect or positive by the ELISA. Of the 156 culture-negative animals, the CF test agreed on 136, the ELISA on 129 and the AGID on 151.     

Failure of porcine reproductive and respiratory syndrome virus to replicate in porcine endothelial cell cultures.

Clinical, gross, and microscopic pathologic and immunohistochemical findings in pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV) suggest that PRRSV may replicate in endothelial cells. Endothelial cell cultures from porcine aorta and pulmonary artery were tested for susceptibility to various strains of PRRSV. Cultures were identified as endothelium by light microscopy and immunohistochemical staining for P-selectin and von Willebrand factor. Five strains of PRRSV, i.e., the National Veterinary Services Laboratories, Ames, IA PRRSV strain 130-PDV and 4 field strains isolated from pneumonic lungs, failed to replicate in these porcine large-vessel endothelial cell cultures.     

Effect of stocking rate, grazing system, and fenbendazole treatment on subclinical parasitism in dairy heifers

Average daily weight and fecal parasitic egg count were compared among sixty 7- to 15-month-old Holstein heifers randomly assigned to 8 groups. The following variables were examined: grazing system (continuous vs rotational), stocking rate (3.5 vs 5 heifers/ha), and treatment [control vs dosing with a 10% suspension of fenbendazole (5 mg/kg of body weight) given orally 21 and 49 days after heifers were placed on pasture]. Two heifers from each group were euthanatized 4 weeks after the completion of the 148-day trial to determine the number of parasitic larvae and adults in the abomasum and intestine. Heifers treated with fenbendazole had significantly (P less than 0.001) fewer fecal ova and fewer inhibited abomasal larvae (P less than 0.05) than did controls. Mean total weight gain and mean daily rate of gain of fenbendazole-dosed heifers were significantly (P less than 0.01) increased by 17.3 kg or 0.12 kg/day, respectively, compared with those of nontreated heifers. Seemingly, stocking rate and grazing systems had no marked effect on subclinical parasitism in heifers.     

Inconsistencies in the absorptive capacities of Schirmer tear test strips

The absorptive capacities of 4 commercially available tear test strips were determined and compared with 5-mm X 40-mm strips of #41 filter paper. Significant differences in the absorption of water over a given time interval were found in 3 of the groups tested. Major inconsistencies were found only within 1 lot of tear test strips from a single manufacturer. Tear test strips from this lot consisted of 2 distinct populations that were distinguishable by transillumination. Strips with widely spaced horizontal lines had the same absorptive capacity as the filter paper, whereas those with fine lines consistently absorbed less water. The clinical importance of this discrepancy was verified by comparing measurements of tear production in 6 normal dogs.     

Hypercalcaemia associated with angiostrongylus vasorum in three dogs

Hypercalcaemia was identified in three dogs that presented primarily for evaluation of respiratory disease. Angiostrongylosis was diagnosed in all three cases and both the respiratory signs and the hypercalcaemia resolved with treatment. Infection with Angiostrongylus vasorum is known to lead to formation of pulmonary granulomata. Granulomatous disease in humans may lead to hypercalcaemia secondary to increased unregulated production of 1,25-dihydroxycholecalciferol by activated macrophages in the granulomata. In one of the three dogs, 1,25-dihydroxycholecalciferol was measured and found to be increased, providing supportive evidence for a similar mechanism in dogs. To the authors' knowledge, hypercalcaemia has not previously been reported in association with angiostrongylosis in dogs. Since prolonged untreated hypercalcaemia may lead to permanent impairment of renal function, dogs with angiostrongylosis should be evaluated for the presence of hypercalcaemia.     

Evaluation of a point-of-care immunodot assay for predicting results of allergen-specific intradermal and immunoglobulin E serological tests

Immunotherapy to prevent recurrence of clinical signs of atopic dermatitis (AD) is based on intradermal or serological tests that assist in identifying allergen-specific immunoglobulin E hypersensitivities. Unfortunately, the results of such tests can be negatively influenced by several factors, which include the age of the patients, the season of testing and the administration of anti-allergic drugs. Screening to predict when these expensive tests will be useful would benefit owners of dogs with AD. The objectives of this study were to determine whether a point-of-care allergen-specific immunodot assay (Allercept E-Screen, Heska Corp., Ft Collins, CO, USA) could predict results of either intradermal or Allercept full panel serological tests in atopic dogs. Thirty dogs living in the south-eastern USA were diagnosed with AD in accordance with current standards. Allergen-specific intradermal, serological and E-Screen tests were performed in all subjects. For flea, house dust mite and pollen allergens altogether, results of the E-Screen assay agreed with those of intradermal and serological tests in 26/30 dogs (87%) and 25/30 dogs (83%), respectively. In this group of dogs, the probabilities of obtaining intradermal or serological tests positive for these allergens were 70 and 67%, respectively. If either skin or serum tests were performed only in dogs with positive E-Screen tests, the probability of obtaining positive results would be increased from 70 to 95% and from 67 to 90%, respectively. In this population of dogs with AD, results of the E-Screen point-of-care immunodot assay was found to often agree with those of allergen-specific intradermal or Allercept tests for selected allergen groups.