Neutralizing and nonneutralizing antibodies to bovine viral diarrhae (BVD) virus were detected in 3 cows persistently infected with noncytopathic BVD virus after vaccination with modified-live cytopathic BVD virus. Neutralizing antibodies detected in serum samples from each persistently infected cow at 3 weeks after vaccination were highly specific for certain isolates of cytopathic BVD virus and reacted only with a viral protein with a molecular weight of 53,000. Neutralizing antibodies to 1 of 3 isolates of noncytopathic BVD virus were detected in a serum sample obtained at 12 weeks after vaccination from 1 of 3 persistently infected cows. Nonneutralizing antibodies were detected in all cows at 7 to 12 weeks after vaccination.The nonneutralizing antibodies were less specific for isolates of BVD virus and reacted with viral proteins with molecular weights of 115,000, 80,000, 53,000, and 47,000.

Four prototype strains of Mycobacterium paratuberculosis contained the type-specific glycopeptidolipid antigen of serovar 8 of the M avium complex. This glycolipid was distinguished by a 4,6-(1'-carboxyethylidene)-3-O-methyl-beta-D-glucopyranosyl terminal unit. Of 59 low-passage, field isolates of M paratuberculosis, 2 contained this antigen, and these 2 isolates were indistinguishable from M avium serovar 8. However, most M paratuberculosis isolates had no characteristic surface glycopeptidolipid. Seemingly, M paratuberculosis, long regarded as a single species and the causative agent of bovine paratuberculosis, is not a homogeneous taxon. Most isolates obtained from infected ruminants may be antigenically defective, variants ofM avium and, thereby, more successful pathogens.

A study was conducted to examine sources of variation introduced into a phagocytosis assay as a result of the isolation of neutrophils from bovine blood, including variation attributable to isolation of neutrophils from blood, variation between duplicate determinations of percentage phagocytosis, and the variation in the ability of neutrophils isolated from blood (over repeated collections from the jugular vein) to phagocytose. For the phagocytosis assay, jugular venous blood from each of 4 cows was divided into 2 equal portions. The neutrophils were isolated by lysis of red blood cells with 0.2% sodium chloride. The neutrophils (2 X 10(7)) were incubated in duplicate with 32P-labeled Staphylococcus aureus ([32P]SA; 2 X 10(8)) inskimmed milk samples (2.5% final concentration) prepared from 4 cows. This process was repeated thrice on neutrophils isolated from 4 cows at 2-week intervals. The proportions of variation in percentage of 32P-labeled S aureus phagocytosed between duplicate neutrophil isolations and between duplicate assay determinations were 0 and 1%. Differences among skimmed milk sources and among runs, using blood neutrophils taken at different times from the same donor cow, accounted for 62 and 36% of the total variation. The results indicated that variation arising from blood neutrophil isolation introduced into a phagocytosis assay within a single-day trial is of no concern. The large variation among skimmed milk sample sources indicated differences among cows in the ability of their milk to support phagocytosis. The variation in neutrophil isolations over time for any cow was considered too large to allow for evaluation of physiologic and environmental effects on phagocytosis of neutrophils isolated from blood.

Foals with the Ca blood group antigen on their RBC were given colostrum with anti-Ca antibodies (6 foals) or colostrum without anti-Ca antibodies (6 foals). The PVC were determined at birth and 2, 4, and 6 days after birth for the foals in each group. Significant differences were not observed for the PCV between the 2 groups, indicating that foals were not adversely affected by ingesting colostrum with the anti-Ca antibody. Standardbred mares without the Aa blood group antigen were evaluated to determine whether production of anti-Ca antibodies influenced production of anti-Aa antibodies. Of 266 mares without the Aa antigen, 3 of 61 (5%) mares without the Ca blood group antigen produced anti-Aa antibodies and 43 of 205 (21%) with the Ca blood group antigen produced anti-Aa antibodies. These 2 groups of mares were significantly (p = 0.006) different; Ca-negative mares were less likely to produce antibodies to Aa than were mares with the Ca blood group antigen. This observation was consistent with a hypothesis of antibody-mediated immunosuppression of immune response to the As blood group antigen by antibodies to the Ca blood group antigen, ie, when a mare is exposed to her foal's RBC and already has antibodies to the Ca blood group antigen on the foal's RBC, then she is less likely to initiate an immune response to the Aa blood group antigen also on the foal's RBC.

The efficacy of water vapor-saturated air as a treatment for horses with exercise-induced pulmonary hemorrhage (EIPH) was studied. Horses selected for study (n = 14) had grade 1 or greater hemorrhage in the trachea after a minimum of 4 breezes between 0.8 and 1 km, as determined by endoscopy. Nine horses were treated with water vapor-saturated air; 5 horses were not treated. When the mean and maximal EIPH scores from the pretreatment period were compared with the mean and maximal EIPH scores from the treatment period in both treated and nontreated groups, there was no significant difference between groups. There was a suggestion of a linear relationship between exercise speed and the mean EIPH score of the first 4 breezes in all 14 horses.

Red blood cells from 6 Pygmy goats were determined to be significantly (P less than 0.01) more susceptible to osmotic lysis and mechanical stress than were RBC from 6 Toggenburg goats. Differences in RBC size and shape and adenosine 5'-triphosphate concentration between the 2 breeds were not significant. The differences observed in the in vitro tests may be attributable to differences in RBC membrane composition.

Nitrofurazone solution containing 0.2% nitrofurazone and 99.8% polyethylene glycol was given to 4 healthy horses (2 L in 2 L of lactated Ringer solution, intraperitoneally). Horses developed hypovolemia, hyperosmolality, and mixed respiratory and metabolic acidosis. These changes were largely attributable to polyethylene glycol, but a contribution of nitrofurazone cannot be excluded. Intraperitoneal infusion of nitrofurazone solution in horses is contraindicated.

A subpopulation of purified, interepithelial lymphocytes from porcine small intestinal mucosa contained cytoplasmic granules. Toluidine blue staining revealed metachromatic granules in 13.64% (606/4,450) cells. The cells had scant organelles, a single large nucleus with obvious invagination of the nuclear membrane, and prominent chromatin. Each cell contained 1 to 10 cytoplasmic membrane-bound granules, 0.6 to 1.5 microns in diameter. These findings indicated that the granular mucosal lymphocytes are related morphologically to mucosal mast cells. The presence of serotonin in the granules, confirmed by the serotonin releasing test, provided functional evidence that granular mucosal lymphocytes are related to mucosal mast cells.

Holstein cow 1 was examined because of skin fragility and delayed healing of skin wounds, which were markedly exacerbated around the time of parturition. A skin biopsy sample was obtained, and light microscopy revealed irregular deposition of thin collagen fibers in a dermal matrix. Although diffuse inflammation did not occur, the number of plump fibroblasts was increased. Electron microscopy revealed poor construction of collagen fibrils in the dermal matrix. Biochemical analysis of the dermis revealed a normal amount of collagen and uronic acid, but sodium dodecyl sulfate-polyacrylamide gel electrophoresis reveled an increased proportion of soluble alpha-, beta-, and gamma-collagen chains of normal molecular weights. Neither procollagen nor its intermediates devoid of amino- or carboxy-terminal extension peptide were observed. Dermal collagen from cow 1 was more soluble in a neutral salt solvent, 0.5M acetic acid, and the acid containing pepsin than was dermal collagen from healthy cow 2. The peptic digestion profile of dermis from cow 1 revealed a lowered degree of intermolecular cross-linking and destabilization of helical structure in the dermis collagen. The extrahelical peptic cleavage of collagen before cyanogen bromide digestion resulted in release of more fragments derived from carboxy-terminal part of alpha1 chains in dermis of cow 1 than in dermis of healthy cow 2.

The efficacy of febantel (5.0 mg/kg) against naturally acquired infections of gastrointestinal nematodes was evaluated in a controlled test in calves during the winter. Twenty steers were allotted to either control or treatment groups of 10 animals each. Seven days after treatment, calves were euthanatized and necropsied for recovery of parasites. Febantel was highly effective against adults of Ostertagia spp (88.6% efficacy based on median), Cooperia spp (97.7%), Trichostrongylus spp (98.2%), Oesophagostomum spp (100%), and Bunostomum phlebotomum (100%). Effects of treatment against adults of Nematodirus spp (100%) were not significant, whereas, degrees of infection of Strongyloides papillosus, Capillaria sp, and Trichuris sp were insufficient for evaluation. The activity of febantel was variable in controlling inhibited and late fourth-stage larvae of Cooperia spp (100% and 100%, respectively) and Ostertagia spp (-81.5% and 36.7%). Numbers of larval Nematodirus and Capillaria sp were insufficient for evaluation. Overall, febantel administered at 5.0 mg/ kg reduced populations of adult and larval strongyles and other gastrointestinal nematodes in calves by 80.7% (P = 0.002). An unexpected finding during the trial was the recovery of Oesophagostomum venulosum from all control calves.