Ultrastructural examination of optic nerve capillaries in the canine lamina cribrosa revealed many spherical, membrane-bound, electron-dense inclusions that closely resembled Weibel-Palade bodies, in pericytes and endothelial cells of preglaucomatous, early, moderately, and advanced affected Beagles with hereditary primary open-angle glaucoma. This ultrastructural difference between the laminar capillary endothelial cells of normal and glaucomatous Beagles could represent a functional vascular disorder, because Weibel-Palade bodies are associated with microcirculatory abnormalities.

A method has been developed for the detection of Brucella abortus in complex tissue homogenates. The technique uses tissue homogenization in the presence of sucrose and Triton X-100 and subsequent filtration through a 5-micrometer pore size filter to remove mammalian nuclei and cellular debris. The DNA from the bacteria is then extracted, dot blotted onto nitrocellulose, and hybridized with a biotinylated probe of B abortus strain 19 DNA. In the present study, BALB/C mice were inoculated intraperitoneally with either 10(9) or 10(11) B abortus strain 2308S organisms. After 6 days, the mice were euthanatized by cervical dislocation and the livers were removed, weighed, and the appearance of each was noted. The tissues were homogenized, and a viable cell count was performed to determine the number of bacteria in each organ. The DNA was extracted, blotted onto nitrocellulose, and hybridized with the Brucella probe. The biotin label was detected by use of a commercially available streptavidin/alkaline phosphatase system. In control experiments, the technique detected 10(5) organisms in a mixture of bacteria and 1 g of rat liver. The technique also detected 10(7) B abortus organisms/g of tissue from experimentally inoculated mice. The probe was specific for Brucella and had no affinity for contaminating bovine or bacterial DNA. ?

Immunochemical methods that are used to assess von Willebrand factor in human beings and dogs were used to assess von Willebrand factor in 3 cat species. Our findings indicated that the expression and multimeric composition of von Willebrand factor in plasma and platelets of cats were similar to those reported in human beings and dogs. We suggest that these methods may be used to evaluate von Willebrand disease in members of the cat family used in this study.

Continous electromyographic recordings of pharyngeal muscle activity were made in 5 clinically normal control dogs and in 7 dogs 3 years after partial denervation of the pharyngeal muscles. Electromyographic recordings were made of the sequence of actions of each muscle and of the combined muscle activity, at rest and during swallowing of food. During 30-second periods, the recordings were digitalized and stored on diskette for further analysis. All control dogs had a distinct pattern of muscle activity during swallowing, the onset being in a constant order (hyopharyngeal, thyropharyngeal, and cricopharyngeal) and bilaterally synchronous. While eating, each dog had about 5 to 12 short periods of synchronous activity in each muscle, between the swallowing actions. During the resting period, there were longer periods of activity, which were synchronous with respiration. In each denervated dog, there were normal and irregular swallowing actions. Swallowing activity was recognized, but the sequence of hyopharyngeal, thyropharyngeal, and cricopharyngeal muscle activity was irregular and different from that in control dogs. Partial denervation of the pharyngeal muscles does not seriously impair motor activity of the muscles, but does alter the sequence of activity in the pharyngeal muscles during swallowing.

Sensory nerve conduction velocity was measured in the lateral palmar nerve of 8 horses. The limb temperature was manipulated by external means and monitored. Alterations in the nerve conduction velocity related to limb temperature variation were identified at both increased and decreased temperatures. These were quantified and a mean value of 2.15 +/- 0.2 m/s/degree Celsius was determined. The effect of altered limb temperature should be considered in nerve conduction velocity determinations.

To evaluate the effects of intra-articular injection of dimethylsulfoxide (DMSO) on normal equine articular structures, 7 adult horses with clinically normal carpi were allotted to 2 treatment groups (group A, n = 4; group B, n = 3). In each horse after collection of synovial fluid samples, the right antebrachial carpal and middle carpal joints were aseptically injected with 2 ml of a 40% solution of 90% medical grade DMSO in lactated Ringer solution, and the corresponding joints of the left forelimb (controls) were injected with 2 ml of lactated Ringer solution. In group-A horses, 2 ml of synovial fluid was obtained prior to injections of 40% DMSO at 24 hours and 72 hours, for a total of 3 injections. At necropsy, synovial fluid, synovial membrane, and articular cartilage specimens were obtained. Group-B horses were injected with 40% DMSO in the same sequence; however, the series was repeated following a 1-week interval. Clinical evaluation of these horses revealed no evidence of carpal inflammation associated with any injection in any group. Synovial fluid analysis of DMSO-injected and control joints revealed insignificant differences in leukocyte counts and total protein content. There was no evidence of cartilage degradation on gross, histologic, or histochemical evaluation of any of the joints. Intercellular matrix staining of the articular cartilage failed to reveal any observable difference in glycosaminoglycan content between injection with DMSO or lactated Ringer solution.

Anthelmintic efficacy of levamisole against induced infections with 7- and 21-day-old Haemonchus contortus, Ostertagia circumcincta, Trichostrongylus axei, and T colubriformis was evaluated as an oral drench in goats. Group 1 (n = 8) was not treated, group 2 (n = 8) was given 3.96 mg of levamisole/kg of body weight, group 3 (n = 8) was given 7.92 mg of levamisole/kg, and group 3 (n = 7) was given 11.88 mg of levamisole/kg. Efficacy against all worms was low in goats given 3.96 mg of levamisole/kg, but was high against adult H contortus (99%) and adult T colubriformis (99.7%) in goats given 7.92 mg of levamisole/kg. Although efficacy against adults of all species was high in goats given 11.88 mg of levamisole/kg, some immature worms of all species remained in the abomasa of goats.

The effects of dietary aflatoxin and ochratoxin, fed singly and in combination, were evaluated in growing crossbred pigs. Five barrows (7 weeks old at beginning of study) per group were fed either control feed, 2.0 mg of aflatoxin (AF)/kg of feed, 2.0 mg of ochratoxin (OA)/kg of feed, or 2.0 mg of AF and 2.0 mg of OA/kg of feed for 28 days. Production performance, serum biochemical, hematologic, and pathologic evaluations were made. Body weights were reduced by the combination treatment, whereas body weight gain was decreased by all toxin treatments. The effect of AF and OA in combination on body weight gain was additive. Liver weights were increased by the combination treatment, whereas kidney weights were increased only in the OA group. Aflatoxin caused decreases in serum calcium, sodium, phosphorus, urea nitrogen, cholesterol, and glucose concentrations, whereas OA alone caused decreases in serum phosphorus, cholesterol, and hematologic values. The AF-OA treatment induced decreases in mean corpuscular volume, packed cell volume, and in serum concentrations of phosphorus, cholesterol, and urea nitrogen. The AF-OA treatment increased serum alkaline phosphatase activities and triglycerides. It was concluded that AF and OA, singly or in combination, can affect clinical preformance, serum biochemical and hematologic values, and organ weights of barrows. Although values of some measurements were affected more by the combination than by either toxin alone and suggested synergism or antagonism, the toxic interactions could best be described as additive.

The potential action of immunologic reactions and mediators released during the course of bovine respiratory syncytial virus infection in pathogenesis of the ensuing disease process was examined in an experimental infection study . Prostaglandin (PG) E2, PGF2 alpha, 6-keto-PGF1 alpha, and thromboxane B2 (TxB2) concentrations were quantitated in plasma and lung lavage fluid by radioimmunoassay at 3- to 4-day intervals during a primary and secondary virus infection of vaccinated, nonvaccinated, and control (mock-infected) calves. A significant increase in the plasma PGE2 concentration for the nonvaccinated calves was noticed on day 3 after primary infection and on day 7 after secondary infection. The PGF2 alpha plasma concentrations increased significantly for the nonvaccinated groups on day 10 after primary infection. Plasma 6-keto-PGF1 alpha concentrations increased for nonvaccinated and vaccinated calves 3 days after the secondary infection. Plasma TxB2 concentrations during the primary exposure did not vary significantly. However, 14 days after the secondary exposure, both experimental groups had concentrations significantly greater than did the control group. Lung lavage fluid concentrations of TxB2 had peaks of activity 7 days after primary and secondary viral infections for the nonvaccinated group. Increases in plasma PG concentrations corresponded variably with disease expression, whereas plasma TxB2 concentrations did not have any correlation with disease expression. However, there was a significant correlation between TxB2 concentration in lung lavage fluid of the nonvaccinated group with disease expression 7 days after primary and secondary virus infection. The potent physiologic effects of PG and TxB2 and their demonstrated production in this infection study suggest that these mediators and the effects of vaccination on their production should be considered as a potentially important factor in the natural disease process.

Specimens of neoplastic tissues from 19 dogs and 4 cats were examined immunohistochemically for intermediate filament expression, using commercially available antibodies. Staining was observed in a wide range of tumor tissues and in normal internal controls by use of antibodies to vimentin, desmin, glial fibrillary acidic protein, and low and high molecular weight cytokeratins. Intermediate filament expression was found to be consistent with light and/or electron microscopic findings, and hence believed to be an accurate indicator of tumor histogenesis in cats and dogs. Three fixatives were evaluated for their relative abilities to preserve antigenicity. Absolute alcohol was superior to B5 fixative and both were superior to formalin. Some tissues that clearly displayed intermediate filament antigens with alcohol and B5 fixative failed to stain when fixed in formalin.