Techniques for the measurement of breath hydrogen excretion have been evaluated in dogs and the breath hydrogen test has been shown to be useful for clinical diagnosis and as a research tool. A simple method was developed for collection of expired air and measurement of breath hydrogen concentrations in cats, which enabled demonstration of carbohydrate malassimilation. Breath hydrogen concentrations were measured in healthy cats after food was withheld and after xylose and lactulose administration. Breath samples were collected by use of an open flow system with the cat confined in an acrylic plastic chamber. Breath hydrogen excretion did not exceed 0.53 ml of hydrogen/h in cats not fed. Breath hydrogen concentrations after the ingestion of xylose, a pentose sugar given orally at 0.75 g/kg of body weight, were not significantly higher from those of cats not fed. After ingestion of 3.35 g of lactulose, a nonabsorbable disaccharide, breath hydrogen excretion increased and breath hydrogen concentrations were significantly higher by 45 minutes (P < 0.05) and 60 minutes (P < 0.01) from breath hydrogen concentrations measured in cats not fed and after xylose administration. Administration of lactulose at an increased dosage resulted in further significant (P < 0.01) increases in breath hydrogen excretion. In this study, mouth-to-cecum transit times were variable. A mean +/- SEM mouth-to-cecum transit time of 86 +/- 6 minutes was calculated from measurement of breath hydrogen excretion after oral administration of 3.35 g of lactulose. Measurements of breath hydrogen concentrations after breath collection by open-flow and closed-flow sampling systems were highly correlated and both variables followed log-normal distributions. The dilution of expired air by the open flow sampling system was not excessive and the results of this correlation study suggested that differences in the assimilation of xylose in healthy cats and dogs may well exist.

Three commonly used keratin monoclonal antibodies (MAB)--AE1:AE3, CAM 5.2, and MAK-6--were compared with routinely used cytokeratin antibody. The expression of these antibodies was analyzed in several tissues obtained from clinically normal dogs and in a variety of neoplasms from dogs. Using appropriate enzymatic digestion, paraffin-embedded tissues processed in routine manner retained their typical keratin expression. Differentiated and poorly differentiated epithelial neoplasms, lymphomas, and melanomas were studied by use of the avidinbiotin-peroxidase technique. All 4 of the aforementioned antibodies had similar staining profiles. Of 3 anaplastic carcinomas, 2 had positive reaction to all 4 antibodies. All lymphomas, plasma cell tumors, and amelanotic melanomas had negative reaction to MAK-6, CAM 5.2, AE1:AE3, and cytokeratin MAB. Three basal cell epitheliomas had positive reaction to all 4 antibodies, whereas 1 basal cell tumor with a solid pattern had negative staining reaction. Two carcinoids had negative reaction to all markers and 1 of 2 malignant chemodectomas and 1 transitional cell carcinoma had staining reaction to only AE1:AE3 MAB. Comparing the 4 antibodies, use of AE1:AE3 MAB produced the strongest staining intensity followed by cytokeratin, MAK-6, and CAM 5.2 MAB. All 4 antibodies had low background staining. In conclusion, AE1:AE3 and MAK-6 MAB are as useful as cytokeratin MAB for identification of poorly differentiated epithelial neoplasms in dogs and cats.

Musculature from 198 Canadian cattle with suspected lesions of eosinophilic myositis were examined histologically and by pepsin digestion. Sera from 51 of the 198 animals were also examined by enzyme-linked immunosorbent assay (ELISA) for anti-Trichinella antibodies. Viable larvae of Trichinella were not recovered from any of the cattle but one animal from Ontario tested positive for anti-Trichinella antibodies. Histologically, focal and/or diffuse eosinophilic myositis lesions were observed in 149 (75.2%) of the animals studied. Other conditions identified were sarcocystiosis, abscesses, cysticercosis, steatosis, fibrosis, granuloma, lymphosarcoma and necrosis. Sarcocystiosis was identified in 105 of the 198 animals in both normal and affected musculature. The study indicates that trichinosis is not a primary cause of eosinophilic myositis in cattle.

Flow cytometric and conventional fluorescence microscopic methods were compared to detect heterologous (rabbit) neutrophil antibody bound to equine neutrophils. Unfixed and paraformaldehyde-fixed neutrophils were treated with normal rabbit serum or various dilutions of an antineutrophil serum. The cells were then reacted with fluorescein conjugates of goat anti-rabbit IgG, staphylococcal protein A, and streptococcal protein G. Antibody binding was evaluated by use of fluorescence microscopy and flow cytometry. Unfixed neutrophils treated with normal rabbit serum did not fluoresce, whereas many of the fixed neutrophils had distinct cytoplasmic and some membranous (nonspecific) fluorescence. Unfixed cells treated with the antiserum had localized areas (capping) of intense membrane fluorescence, whereas fixed cells had bright uniform membranous fluorescence. The intensity of specific fluorescence varied with the antiserum dilution and the conjugate. On flow cytometry, over 80% of unfixed cells treated with antiserum dilutions up to 1:1,024, 1:2,048, and 1:256 fluoresced, respectively, with anti-IgG, protein-G, and protein-A conjugates. Fixed cells generally had similar percentages of fluorescent cells, but at a higher (1-step) antiserum dilution. It was concluded that flow cytometry is more sensitive than conventional fluorescence microscopy to detect antibodies associated with equine neutrophils.

Three ejaculates from each of 3 stallions were used to evaluate a computerized system (Hamilton-Thorn motility analyzer; HTMA) for measuring equine spermatozoal motility. Variance components (ejaculate-within-stallion, chamber-within-ejaculate, and microscopic field-within-chamber) were determined for each stallion after diluting ejaculates to 25 X 10(6) spermatozoa/ml with a skim milk-glucose seminal extender. The HTMA was compared with frame-by-frame playback videomicrography (VIDEO) for determining: percentage of spermatozoal motility and spermatozoal number in microscopic fields; curvilinear velocity and straight-line velocity of individual spermatozoa for 5 track types; and repeatability of those velocity measurements. The effect of spermatozoal number per microscopic field on incidence of intersecting spermatozoa and the outcome of intersecting spermatozoa also were evaluated. Greatest variability in motility measures was generally attributed to the microscopic field-within-chamber component. The HTMA was highly correlated with VIDEO for estimation of spermatozoal numbers per microscopic field (r = 0.99; P <0.001) and motility (r = 0.97; P <0.001); however over the entire range of spermatozoal numbers, the HTMA yielded higher spermatozoal numbers per microscopic field (P <0.05) and higher motility (P <0.05) than did VIDEO. The HTMA- and VIDEO-derived measurements of curvilinear and straight-line velocities were highly correlated for all spermatozoal track types, but both measures were higher (P <0.05) by use of the HTMA than by use of VIDEO for most track types. For 3 of 5 track types, measurements of curvilinear and straight-line velocities were less variable (P <0.05), using the HTMA, rather than VIDEO. Using the HTMA, the number of intersecting spermatozoa was highly correlated with spermatozoal numbers per microscopic field (r = 0.97; P <0.001). The percentage of erroneous track interpretations involving intersecting spermatozoa was high (85.3 +/- 2.7%). The HTMA was a reliable system for determining percentage of spermatozoal motility and velocity measures in video recordings of equine semen diluted to spermatozoal concentration of 25 X 10(6)/ml prior to evaluation.

To evaluate renal function and obtain reference values for measurements of urinary excretion of various substances, quantitative urinalysis was performed in healthy, growing kittens from 4 to 30 weeks after birth. Endogenous creatinine clearance, 24-hour urine protein excretion, and urine protein-to-creatinine ratio were determined. Additionally, fractional excretion to creatinine clearance was calculated for calcium, inorganic phosphorus, sodium, potassium, and chloride. Mean +/- SD endogenous creatinine clearance values (range, 3.80 +/- 0.48 to 4.74 +/- 0.61 ml/min/kg) were significantly (P < 0.0001) higher in kittens 9 to 19 weeks old, compared with younger (range, 1.39 +/- 0.85 to 3.59 +/- 0.86 ml/min/kg) and older kittens (range, 2.69 +/- 0.40 to 3.46 +/- 0.37 ml/min/kg). Mean values for all kittens for 24-hour urine protein excretion (range, 2.54 +/- 1.81 mg/kg at 4 weeks to 11.39 +/- 7.61 mg/kg at 14 weeks) and for urine protein-to-creatinine ratio (range, 0.14 +/- 0.03 to 0.34 +/- 0.18) varied from week to week of age. The urine protein-to-creatinine ratio in kittens greater than or equal to 9 weeks old correlated well (R2 = 0.861) with 24-hour urine protein excretion. Urinary fractional excretion of calcium, inorganic phosphorus, sodium, potassium, and chloride in kittens varied among age groups, being significantly (P < 0.01) different for potassium and calcium in young kittens (4 to 6 weeks) and older kittens (greater than or equal to 7 weeks).

The composition and structure of 48 canine cystine urinary stones were determined by infrared spectroscopy, scanning electron microscopy and electron dispersive X-ray analysis. The infrared analysis showed that about 45% of the specimens were composed of pure cystine. The remainder also contained calcium oxalate (mono and/or dihydrate), magnesium ammonium phosphate hexadydrate (struvite), calcium hydrogen phosphate dihydrate (brushite) and complex urates (ammonium, ammonium potassium and/or potassium enriched ammonium urate). The infrared study of several samples heated at 620 degrees C and 750 degrees C revealed the presence of apatitic calcium phosphate. This compound was difficult to detect in the spectrum of the original samples due to the small proportion of phosphate contained in the calculi and to band overlapping. The examination of a series of selected samples by means of scanning electron microscopy and energy dispersive X-ray analysis complemented the infrared results.

A nuclear imaging technique of the stomach, using technetium pertechnetate (99mTcO4), was evaluated in healthy dogs. The stomach was first insufflated with room air, then filled with barium sulfate to induce mild distention, outlining the gastric wall. Six dogs were imaged twice: initially without use of drugs that might affect gastric secretion of 99mTcO4, then after pretreatment with cimetidine and glycopyrrolate. These scans established the appearance of the normal (control) stomach and compared the quality of the image in the same dogs not pretreated, then pretreated with cimetidine and glycopyrrolate before administration of 99mTcO4. Avascular defects were then surgically created on the greater curvature of the stomach of the same 6 dogs, and gastroscintigraphy was performed in similar manner. Significant (P < 0.05) quantitative differences were detected in the gastric images for scans of the avascular area, compared with various control scans. Qualitative assessment had overall accuracy of 90.28%. Results of the study reported here indicate that nuclear imaging can be a valuable diagnostic technique for detecting ischemic areas in the gastric wall of dogs.

A technique for detection of bovine viral diarrhea virus (BVDV) from circulating blood leukocytes, using the polymerase chain reaction, is described. The published nucleotide sequences of 2 strains of BVDV and that of hog cholera virus were aligned and the information was used to design oligonucleotides coding for 2 regions of amino acid homology. The oligonucleotides were a mixed population including all possible codons for the conserved amino acids. These degenerate oligonucleotides were used in the polymerase chain reaction to detect viral RNA in cells infected in vitro, or in circulating blood leukocytes from infected animals. Virus was detected in over 60 samples from diverse isolates. The detection of BVDV by the polymerase chain reaction is a rapid, sensitive, and specific technique, which represents an improvement over existing technology.

An ELISA was developed and tested for its ability to detect antibodies against Salmonella enteritidis in chickens. Various features of the ELISA were evaluated and optimized. The outer membrane protein antigens selected by use of the protein immunoblotting method made the assay specific and sensitive. The assay was evaluated in chickens experimentally infected with S enteritidis. Blood samples collected at weekly intervals after experimental infection with S enteritidis were analyzed by ELISA. Results of the ELISA were compared with those of conventional serum plate and microagglutination tests. The ELISA was more sensitive and specific in the detection of S enteritidis infection than the other 2 conventional tests.