Exogenous creatinine clearance, urinary electrolyte excretions, calcium and phosphorus balance, serum cholesterol concentration, arterial blood pressure, and body weight were evaluated in dogs with chronic renal failure that were fed 2 commercial diets. Nine dogs ranging in age from 1 to 15 years were identified as having mild to moderate chronic renal failure (CRF, exogenous creatinine clearance = 0.5 to 2.13 ml/kg of body weight/min). These dogs and a group of 10 clinically normal controls were fed a diet containing 31% protein for 8 weeks at which time hematologic and biochemical evaluations and clearance studies were performed. All dogs then were fed a phosphorus-restricted diet containing 16% protein and then reevaluated after 8 weeks. The dogs in this study had hematologic and biochemical abnormalities typical of CRF. Urine absolute and fractional excretion of electrolytes was higher in dogs with CRF than in controls and was affected by diet. Serum cholesterol concentration was higher in dogs with CRF and increased in those dogs after feeding the low protein diet. Changes in dietary sodium intake did not affect arterial blood pressure. The phosphorus-restricted diet did not affect serum amino terminal parathyroid hormone concentration in either group. Control dogs lost body weight, whereas dogs with CRF gained weight when fed the low protein diet. We concluded that dogs with mild to moderately severe CRF have the same biochemical abnormalities and response to dietary restriction of protein and phosphorus as has been previously reported in dogs with experimentally induced CRF. Restriction of dietary sodium may not decrease arterial blood pressure in some dogs with CRF. Dogs with CRF may be predisposed to hypercholesterolemia when fed restricted protein commercial diets, and reduction of dietary phosphorus intake may be inadequate to control renal secondary hyperparathyroidism in dogs with CRF.

Although low plasma taurine concentrations have been associated with congestive cardiomyopathy in cats, the cause of taurine depletion in cats consuming adequate quantities of taurine is unknown. Taurine depletion and cardiovascular disease (cardiomyopathy and thromboembolism) developed unexpectedly in 3 of 6 healthy adult cats during a potassium-depletion study. Plasma taurine concentration decreased significantly (P < 0.05) and rapidly over an 8-week period (from 98 to 36 nmol/ml) in 6 cats that consumed a potassium-deficient diet (0.20% potassium, dry matter basis) that was acidified with 0.8% ammonium chloride, despite containing dietary taurine concentrations (0.12% dry matter basis) in excess of amounts currently recommended. Taurine concentrations were significantly lower in cats fed the acidified diet than in 6 cats fed a potassium-deficient diet that was not acidified (36 nmol/ml vs 75 nmol/ml) after 8 weeks. In addition, plasma taurine concentrations did not decrease over a 6-month period in 8 cats that were fed a potassium-replete diet with acidifier. Plasma taurine concentrations were lowest in 3 cats that died of cardiovascular disease in the group receiving potassium-deficient, acidified diets. These data indicated an association between taurine and potassium balance in cats and suggested that development of taurine depletion and cardiovascular disease may be linked to concurrent potassium depletion.

Zoometric measurements and bioelectrical impedance analysis were evaluated as methods of body composition determination in healthy cats. Zoometric and impedance measurements were taken on 22 anesthetized adult cats of various ages, genders, breeds, and body weights. The cats were then euthanatized. The bodies were processed through a tissue homogenizer and free-catch specimens were taken, freeze-dried, and analyzed for total body water, protein, fat, potassium, and ash content. Stepwise regression analysis was implemented to identify statistically significant relationships between the chemically determined dependent variables (total body water, protein, potassium, fat-free mass, fat mass, and percent body fat) and the zoometric measurements, with or without bioelectrical impedance analysis. Statistical analysis revealed high correlations between the dependent variables and the corresponding predicted values of those variables. Body weight alone was a poor predictor of body composition in these cats. On the basis of these findings, we suggest that zoometric and bioelectrical impedance measurements may serve as practical, noninvasive, simple, and accurate methods for estimating body composition in domestic cats.

Ceftiofur sodium, a broad-spectrum cephalosporin antibiotic, was evaluated for safe use in horses. Male or female horses were allotted to groups and were given either saline solution (control), or 2.2, 6.6, or 11 mg of an aqueous solution of ceftiofur sodium/kg of body weight/d, IM, for 30 or 31 days. These dosages are expressed in terms of the ceftiofur free acid, and represent 1 to 5 times the proposed therapeutic dosage (2.2 mg/kg/d) administered for 3 times the maximal recommended duration of 10 days. Some of the horses were euthanatized and necropsied on day 31 or 32. The other horses were evaluated for an additional 30 days, and some were euthanatized and necropsied on day 60. The following types of data were collected: clinical observation; physical examination; pelleted food consumption; body weight; hematologic, serum biochemical, and urinalysis findings; organ weight; gross necropsy observations; and histopathologic findings. Ceftiofur sodium was generally well tolerated at the exaggerated doses and treatment durations used in these safety studies. Slight to mild decrease in pelleted food consumption was detected in horses given 6.6 or 11 mg of ceftiofur sodium/kg/d. Decreased food consumption began on day 2 and lasted for approximately 9 to 12 days. Generally, mild skeletal muscle irritation was detected by gross and microscopic examination of the injection sites of horses given ceftiofur sodium. Prevalence and severity of the muscle irritation tended to increase with increasing concentration of the dosing solution. Increases in serum aspartate transaminase and creatine kinase activities were detected in some of the ceftiofur-treated horses, and were attributed to mild skeletal muscle irritation at the injection sites. Slight increases in numbers of circulating neutrophils and plasma concentration of fibrinogen were detected in the blood of some ceftiofur-treated horses, and were attributed to mild inflammation at the injection sites or possibly in the large intestine because of a change in bacterial flora.

The bioavailability and pharmacokinetics of ibuprofen, a nonsteroidal antiinflammatory drug, was studied in healthy Shetland ponies. Ibuprofen was administered IV, as a suspension, and as a solid solution oral paste to ponies from which food was withheld. The suspension paste was also administered to ponies that received hay and water ad libitum. Both formulations had an absolute bioavailability of about 80%. Bioavailability was not influenced by feeding.

In 2 trials, the efficacy of an in-feed preparation of ivermectin was evaluated in 40 pigs naturally infected with endoparasites and Sarcoptes scabiei var suis. Treated pigs (n = 10 in each trial) were fed a ration containing 2 ppm ivermectin for 7 days, followed by consumption of a nonmedicated ration for the remainder of the trial. Control pigs (n = 10 in each trial) were fed a complete, nonmedicated ration for the duration of the trial. Pigs in trial A were monitored for 14 days after treatment; those in trial B were monitored for 35 days after treatment. In trial A, treatment efficacy of ivermectin was 100% against Ascaris suum, Physocephalus sexalatus, Oesophagostomum dentatum, O brevicaudum, Metastrongylus spp; 99.8% against Ascarops strongylina; 90.9% against Trichuris suis; and 13.1% against Macracanthorhynchus hirudinaceus. At the terminus of the trial, statistically significant (P < 0.05) differences were observed between numbers of treated and control pigs infected with A suum, Ascarops strongylina, and Oesophagostomum spp. On posttreatment day 14, S scabiei were not found in any scrapings taken from treated pigs, but were found in scrapings from 3 of 10 control pigs. The number of infested pigs in the treatment group was not statistically different from the number of infested pigs in the control group. In trial B, treatment efficacy was 100% for A suum and Metastrongylus spp; 96.9% for Ascarops strongylina; and 76.9% for M hirudinaceus. At the terminus of the trial, statistically significant (P < 0.05) differences were evident between numbers of treated and control pigs infected with A suum, Ascarops strongylina, and Metastrongylus spp. On posttreatment days 7, 2 1, and 35, S scabiei were not found in scrapings taken from treated pigs. On posttreatment days 7, 2 1, and 35, S scabiei were found in scrapings from 8, 6, and 1 pig, respectively, whereas live mites were not found on scrapings taken from treated pigs on these days. Statistically significant (P < 0.05) differences were evident between the numbers of infested pigs in the treated and control groups on days 7 and 21. Ivermectin fed to swine ad libitum in a complete ration at 2 ppm was shown to be highly effective as an anthelmintic and acaricide.

Acyloxyacyl hydrolase (AOAH) is a lysosomal enzyme found in neutrophils and macrophages that acts to partially deacylate the lipid-A component of the endotoxin of gram-negative bacteria rendering it less toxic, yet maintaining much of its immunostimulatory potential. We have found that the activity of neutrophil AOAH per cell increased during localized inflammation. The purpose of this study was to determine the mechanism(s) responsible for these increases in neutrophil AOAH activity. Because changes in neutrophil maturity commonly are associated with inflammation, intravascular infusion of purified gram-negative bacterial lipopolysaccharide and SC injection of bovine recombinant granulocyte colony-stimulating factor was used to induce large numbers of circulating immature neutrophils. Immature neutrophils were found to have AOAH activity equal to that of mature cells; however, when neutrophils were stimulated in vitro with known activators, AOAH activity of activated cells was more than that of unstimulated cells. The increase in AOAH activity was inversely related to prestimulation activity. Increases in AOAH activity after neutrophil activation were not a result of de novo synthesis of the enzyme, because cycloheximide did not prevent activation-induced increases in activity.

Thirty-two bovine field isolates of bluetongue virus (BTV), 6 field isolates of epizootic hemorrhagic disease virus (EHDV) from deer, 4 BTV prototype serotypes (10, 11, 13, and 17), and 2 EHDV prototype serotypes (1 and 2) were coelectrophoresed, using polyacrylamide gels. Field isolates were obtained from various regions of the United States. Analysis of polyacrylamide gels and scattered plots generated for comparison of migration patterns for different isolates within each serotype of BTV revealed wide variation among the individual segments. The BTV serotypes 10 and 11 had more variation, compared with BTV serotypes 13 and 17, especially for migration of genome segment 5. A definitive correlation was not seen between the double-stranded RNA migration profiles on polyacrylamide gel electrophoresis, geographic origin, herd of origin, or year of collection. One BTV field isolate contained more than 1 electropherotype, with 2 bands at the segment-7 position, and it was further characterized as BTV serotype 11. Segments 2 and 5 of EHDV isolates were more variable in their migration than were the other gene segments. Generally, migration profiles for EHDV double-stranded RNA were more variable, compared with those of BTV isolates. Although a correlation was found between migration profiles and serotype of 2 isolates of EHDV, a study of additional EHDV isolates is required before the diversity of electrophoretic patterns of EHDV can be determined.

Swab specimens for fungal isolation were collected from the healthy conjunctival sacs of 3 species of captive camelids (Lama glama, L guanicoe, L pacos) and llama-guanaco hybrids. Fungi were collected from over half the animals in winter (53%) and summer (56%). Fungal species of 10 genera were isolated. In both seasons, Aspergillus was the most commonly isolated genus; at least 9 species of Aspergillus were found. The fungal organisms isolated were similar to those found in healthy eyes of other domestic animals and may represent a random seeding from the environment where they are ubiquitous.

Pigs [9+/-1] weeks old) were inoculated with Streptococcus suis type 2, pseudorabies virus (PRV) or both. For each pig of groups A, B, and C the inoculum of S suis was 10(9) colony-forming units. For each pig of groups A, B, and D the inoculum of PRV was 5 X 10(3) TCID50 of either PRV strain 4892 (group A, n = 9) or PRV isolate B (group B, n = 9). The PRV strain 4892 is a highly virulent strain; isolate B causes mild clinical signs of infection in inoculated pigs. Group-C pigs (n = 9) were given S suis alone, and group-D pigs (n = 3) were inoculated only with PRV isolate B. Clinical signs of infection and development of lesions were readily seen in pigs of groups A, B, and C. Duration and severity of clinical signs of disease and lesions were reduced in pigs of group C, compared with those of the other 2 groups. Lesions, such as polyarthritis and fibrinous pericarditis, were more abundant and acute in the groups of pigs given mixed challenge exposure, compared with pigs inoculated exclusively with S suis type 2 (group C). The group of pigs inoculated with PRV isolate B alone did not manifest clinical signs of disease or lesions. Average daily gain for group-C pigs was higher, compared with that of other groups; the difference was statistically significant at P < 0.02 and P < 0.05 for groups B and D, respectively. Spread of S suis within the tissues of infected pigs was higher in pigs of groups A and B, compared with pigs of group C. Total number of isolations was 8, 15, and 7 for groups A, B, and C, respectively; S suis was isolated from more than 1 tissue specimen from some pigs. The rate of pigs carrying S suis was 4 of 4 in group-A, 7 of 9 in group-B, and 5 of 9 in group-C pigs. It was concluded that clinical disease associated with S suis type 2 was enhanced by concomitant infection with PRV and such effect was common to both PRV strains tested, the highly virulent strain and the strain with low virulence.