The influence of induced chronic renal failure on 24-hour urinary excretion and fractional excretion of sodium and potassium was studied in cats. Induction of chronic renal failure significantly increased fractional excretion of potassium (P < 0.0001) and sodium (P < 0.05); however, 24-hour urinary excretion of sodium and potassium decreased slightly following induction of chronic renal failure. Fractional excretion and 24-hour urinary excretion of sodium and potassium were compared by linear regression in clinically normal cats, cats with chronic renal failure, and clinically normal and affected cats combined. In clinically normal cats, linear regression revealed only moderate correlation between fractional excretion and 24-hour urinary excretion for sodium and potassium. Linear regression of these same relationships in cats with chronic renal failure, and in clinically normal cats and cats with chronic renal failure combined, indicated low correlation. Fractional excretions of sodium and potassium were not reliable indicators of 24-hour urinary excretion of these electrolytes in cats with chronic renal failure or unknown glomerular filtration rate. Fractional excretion of potassium and sodium correlated only moderately with urinary excretion in clinically normal cats.

To determine the effects of 9 sedative/anesthetic drug protocols on intradermal skin testing, an experimental state of type-I hypersensitivity was created. Intradermal skin tests were performed on 6 dogs, using positive and negative controls and a series of tenfold dilutions of ASC-1 allergen prior to drug administration. Approximately 4 hours later, the dogs were given 1 of the following drugs: acepromazine (low dose and high dose); ketamine hydrochloride with diazepam; thiamylal; oxymorphone; halothane; methoxyflurane; or isoflurane. The intradermal skin test then was repeated, and was scored objectively and subjectively. Objective scores were unaffected by any of the drugs. Subjective scores were affected in that acepromazine decreased wheal size and the induration of the intradermal skin test reaction sites.

To compare the effects of milk stasis and milk flow on Brucella abortus infection of the mammary gland under the same systemic conditions, primiparous goats (n = 5) were inoculated IV with B abortus on the day of parturition, and suckling by their neonates was restricted to one mammary gland. Goats were euthanatized and necropsied at 3 weeks after inoculation, and milk, mammary glands, and supramammary lymph nodes were evaluated by bacteriologic, histologic, and immunoenzymatic staining techniques. Nonnursed mammary glands had high titers of brucellae in milk, moderate interstitial mastitis, and brucellar antigen in macrophages located primarily in alveolar and ductal lumina. Brucellae often filled the macrophage cytoplasm. In contrast, nursed mammary glands had fewer brucellae in milk, minimal inflammatory changes, and no detectable brucellar antigen in histologic sections. Hyperplastic changes were only seen in supramammary lymph nodes draining nonnursed mammary glands; these contained more brucellae than lymph nodes draining nursed mammary glands. These studies show that milk stasis may be the sole cause of increased susceptibility of nonnursed mammary glands to B abortus infection.

Urethral pressure profiles (UPPs) were recorded in ten adult healthy male cats before and after administration of either phenoxybenzamine, diazepam, nifedipine or xylazine. A significant decrease (p < 0.05) in urethral pressure at the level of the prostate was observed following treatment with all drugs. Xylazine produced a significant decrease in urethral pressure 4 to 7 cm from the tip of the penis in healthy male cats. None of the drugs used decreased urethral pressure in the zones of pure striated muscle or pure smooth muscle in these cats, making current recommendations for pharmacological management of urethral spasm suspect. Further studies are necessary to evaluate clinical cases of urethral spasm and to study the effects of these drugs on the urethral pressure of cats suffering from this spasm.

Interregional, as well as intraregional (local), distributions of the inhalation-to-perfusion ratio were analyzed in the lungs of 20 prone anesthetized healthy dogs--10 dogs with barrel-shaped thorax (Beagles) and 10 dogs with deep thorax (Greyhound-type dogs)--using 99mTc inhalation-perfusion lung scintigraphy. Dorsoventral and lateral views were analyzed. In both types of dogs, the ratio between the mean inhalation and perfusion values (interregional mismatching factor) decreased from craniad to caudad and the decrease was more sustained in the right than in the left lung. However, the total decrease was less in Greyhound-type dogs than in Beagles (cranial-to-caudal decrease of 14 and 27%, respectively, in the left lung, and 62 and 56%, respectively, in the right lung). The dorsal-to-ventral distribution of interregional mismatching factor was different in the 2 types of dogs. In Beagles, it increased from dorsal to ventral zones by about 50% of the initial dorsal zone value, whereas in Greyhound-type dogs, only a slight dorsal-to-ventral decrease was evident, with the exception of the more ventral zone. Differences in the intraregional mismatching factor (rho) indicated that the intraregional inhalation-to-perfusion inequalities were more pronounced within the caudal regions and within the ventral zones of the lungs in both types of dogs, and in the more cranial zones in the lungs of Beagles. However, the degree of intraregional mismatching was generally lower in Greyhound-type dogs. Thus, the gravitational force is not the dominating determinant of interregional or intraregional inhalation-to-perfusion ratio distributions in the lungs of anesthetized prone dogs. Its influence is modulated by other factors morphologic characteristics, such as the shape and size of the thorax, and body weight of the dog. In particular, the height of the thorax in Greyhound-type dogs could permit the gravitational force to exert a more determinant influence than it does in Beagles.

A cross-sectional epidemiologic study associating air quality with swine health was conducted on 28 swine farms in southern Sweden. Correlation of housing air environment to swine diseases and productivity (data collected over the preceding 12 months) were investigated. The most prevalent swine health problems detected at slaughter were pneumonia and pleuritis. In farrowing and nursery operations, the most prevalent problem was neonatal pig mortality. Several air contaminants (dust, ammonia, carbon dioxide, and microbes) were found to be correlated with these swine health problems. Maximal safe concentrations of air contaminants were estimated on the basis of dose-response correlation to swine health or human health problems. Recommended maximal concentrations of contaminants were: dust, 2.4 mg/m3; ammonia, 7 ppm; endotoxin, 0.08 mg/m3; total microbes, 10(5) colony-forming units/m3; and carbon dioxide, 1,540 ppm. The overall quality of the ventilation system was correlated with lower concentration of ammonia, carbon dioxide, microorganisms, and endotoxin, but not with dust concentrations. High animal density was related to high ammonia and air microbe concentrations. Animal density measured as kilograms of swine per cubic meter (compared with kilograms of pig weight or swine per square meter) had the highest correlation to animal health and air contaminants.

Polymorphonuclear cells have a critical role in the pathogenesis of bovine mastitis. We have documented that experimentally induced Staphylococcus aureus mastitis is associated with cyclic increase and decrease in the quantity of viable bacteria shed in the milk. Concomitant with this cycling of bacteria is an inverse cycling of the hosts cells within the milk. Such somatic cells were determined to be greater than or equal to 95% polymorphonuclear cells. The quality of these cells was evaluated by measuring their relative efficiency of bacterial killing and phagocytosis at various times during an infection. Host polymorphonuclear cells had as much as 10,000-fold variation in the bactericidal failure rate for staphylococci during cell cycling. The most efficient bactericidal effect was observed at or near the peak of the somatic cell count (SCC). The ability of these cycling cells to ingest fluorescent beads was also quantitated by use of flow cytometry. The percentage of phagocytic polymorphonuclear cells that ingested fluorescent latex beads ranged from 15 to 80% of the total cell population during cell cycling, and tended to be optimal at or near peak SCC. In addition, the average number of beads ingested varied between 1 and 2 particles/polymorphonuclear cell, with as many as 17% of the phagocytic cells ingesting 4 or more beads at maximal efficiency. Polymorphonuclear cells from quarters infected with S aureus varied quantitatively (total SCC) and qualitatively (bactericidal activity and phagocytic ability) during the course of an infection. Not only is the quantity of host's phagocytic cells in the mammary gland central to the defense mechanism against infection, but the biological activation state appears to be equally important. The role of these cells in the pathogenesis of a cycling infection is presented in a model to explain the cyclic nature of mastitis.

Periosteal autograft were used for repair of large osteochondral defects in 10 horses aged 2 to 3 years old. In each horse, osteochondral defects measuring 1.0 X 1.0 cm2 were induced bilaterally on the distal articular surface of each radial carpal bone. Control and experimental defects were drilled. Periosteum was harvested from the proximal portion of the tibia and was glued into the principal defects, using a fibrin adhesive. Control defects were glued, but were not grafted. Sixteen weeks after the grafting procedure, the quality of the repair tissue of control and grafted defects was assessed biochemically. Total collagen content and the proportion of type-II collagen were determined. Galactosamine and glucosamine contents also were determined. From these measurements, contents of chondroitin and keratan sulfate and total glycosaminoglycan, and galactosamine-to-glucosamine ratio were calculated. All biochemical variables were compared with those of normal equine articular cartilage taken from the same site in another group of clinically normal horses. Total collagen content was determined on the basis of 4-hydroxyproline content, using a colorimetric method. The proportions of collagen types I and II in the repair tissue were assessed by electrophoresis of their cyanogen bromide-cleaved peptides on sodium dodecyl sulfate slab gels. Peptide ratios were computed and compared with those of standard mixtures of type-I and type-II collagens. Galactosamine and glucosamine contents were determined by use of ion chromatography. In general, the biochemical composition of repair tissue of grafted and nongrafted defects was similar, but clearly differed from that of normal articular cartilage. Total glycosaminoglycan content, galactosamine and glucosamine contents, and galactosamine-to-glucosamine ratio of grafted and nongrafted defects were all significantly (P < 0.05) less than corresponding values in normal equine articular cartilage. By contrast, total collagen content of neocartilaginous tissues of grafted and nongrafted defects was greater than that of normal articular cartilage, although the difference was not significant. The proportion of type-I and type-II collagens in repair tissue in grafted and nongrafted defects was 70 and 30%, respectively. The fibrous nature of the repair tissue reported in a companion morphologic and histochemical study was substantiated by the biochemical results. We concluded that use of periosteal autograft did not improve the healing of osteochondral defects.

Bovine herpesvirus type 1 (BHV-1) isolates are classified into 3 subtypes by use of restriction endonuclease analysis. Isolates from aborted fetuses have been either subtype 1 or 2a, whereas subtype 2b viruses have not been associated with abortion. We assessed the abortifacient property of isolates representing each of the 3 BHV-1 subtypes by IV inoculation of heifers with the virus 25 to 27 weeks after breeding. Three heifers were given Cooper (subtype 1) isolate, 3 heifers were given FI (subtype 2a) isolate, and 5 heifers were given K22 (subtype 2b) isolate. All heifers developed fever and viremia 2 to 5 days after inoculation. Heifers given Cooper or FI isolate aborted between 17 and 85 days after inoculation. The 5 heifers given K22 isolate delivered full-term calves. Placenta was obtained from 4 of the 5 heifers, and K22 virus was isolated from each placenta. Four calves had BHV-1 neutralizing antibody in precolostral serum, with titer ranging from 1:4 to 1:512.

Eighteen healthy dogs were allotted to 3 groups (n = 6 dogs each). All dogs were evaluated at the beginning of the study by complete physical examination; total and differential WBC counts; serum biochemical analysis (alanine transaminase and alkaline phosphatase activities and bilirubin and albumin concentrations); sulfobromophthalein excretion, ammonia tolerance, and glucagon response testing; portal and intraparenchymal pressure determinations; operative mesenteric portography; and histologic assessment of hepatic biopsy specimens. The left hepatic vein was ligated completely in dogs of groups 1 and 2. Group-3 (control) dogs had a ligature placed loosely around the left hepatic vein. Dogs of groups 1 and 3 were reevaluated 24 hours after surgery by use of the aforementioned hematologic and biochemical tests. Group-1 dogs were reevaluated by use of portal and intraparenchymal pressure determinations, jejunal vein portography, and complete necropsy at 48 hours after surgery. At 4 weeks after surgery, dogs of groups 2 and 3 were reevaluated by use of all aforementioned tests. Results indicated transient hepatic congestion, which resolved by the fourth postoperative week. Longstanding effect on hepatic structure, circulation, or function was not found. We concluded that left hepatic vein ligation in clinically normal dogs does not cause severe or permanent liver damage.