A commercially available radioimmunoassay (RIA) kit for measurement of human adrenocorticotropin (hACTH) was validated for use in dogs. Assay sensitivity was 3 pg/ml. Intra-assay coefficient of variation (X 100; CV) for 3 canine plasma pools was 3.0 (mean +/- SD, 33 +/- 0.99 pg/ml), 4.2 (71 +/- 2.4 pg/ml) and 3.7 (145 +/- 3.7 pg/ml) %. Interassay CV for 2 plasma pools measured in 6 assays was 9.8 (37 +/- 3.6 pg/ml) and 4.4 (76 +/- 3.4 pg/ml) %, respectively. Dilutional parallelism was documented by assaying 2 pools of canine plasma at 3 dilutions and correcting the measured result for dilution. Corrected mean concentrations for the first pool were 33 (+/- 0.99), 36 (+/- 4.3), and 33 (+/- 6.8) pg/ml; corrected mean concentrations for the second pool were 145 (+/- 5.4), 141 (+/- 10.8) and 125 (+/- 3.4) pg/ml. Recovery of 1-39hACTH added to canine plasma (6.25, 12.5, 25.0, 50.0, and 100.0 pg/ml) was linear and quantitative (slope = 0.890, R2 = 0.961). To test whether anticoagulant or the protease inhibitor, aprotinin, influences ACTH concentration in canine plasma, ACTH was measured in canine blood collected in 4 tubes containing anticoagulant: heparin (H), heparin + 500 kallikrein inhibitor units (KIU) of aprotinin/ml (HA), EDTA (E), and EDTA + aprotinin (EA). Plasma ACTH concentration was the same when samples containing H and HA, or HA and E were compared, and was significantly (P < 0.01) lower in samples containing EA. Plasma storage at -20 C for 1 week or 1 month was not associated with significant change in ACTH concentration in canine plasma, using any of the 4 anticoagulant treatments. Plasma ACTH concentration measured after 6 months' storage at -20 C was significantly (P < 0.01) lower for all anticoagulants used. Synthetic 1-39hACTH added to canine blood was accurately recovered (88 to 109%, n = 3) from plasma containing EDTA, with or without aprotinin, whereas percentage recovery was overestimated by 18 to 91% in heparinized plasma. Plasma ACTH concentrations in EDTA-treated canine blood kept at 4 or 22 to 25 C for 15 to 90 minutes prior to centrifugation at 8 C were not significantly different. Plasma ACTH concentration in canine plasma was affected by storage tube material. Concentration of ACTH in canine plasma stored in borosilicate glass tubes for 1 week or 1 month at -70 C was significantly higher than initial ACTH values (P less than or equal to 0.01), but was unchanged over time in plasma stored in polypropylene or polystyrene tubes. Sample handling procedures affect canine plasma ACTH concentration measured by use of the RIA kit. Optimal sample handling conditions for plasma ACTH measurement in dogs include use of EDTA anticoagulant, blood collected at 20 to 25 C (room temperature) followed by centrifugation within 15 to 90 minutes, and plasma storage in plastic (not glass) tubes for not longer than 1 month at -20 C.

Previous work indicated that adult Ancylostoma caninum can be removed from experimentally infected dogs, using a formulation of milbemycin oxime at dosage of 0.5 mg/kg of body weight. To determine the efficacy of this treatment in dogs naturally infected with adult hookworms, 24 mixed-breed dogs with patent hookworm infections were purchased from an out-of-state vendor, and 6 male and 6 female dogs were assigned to either a control group or a group that would be treated. Dogs were treated 10 days after their arrival and were euthanatized 1 week after treatment. Beginning 3 days before treatment, fecal samples were collected daily from all dogs, and the number of Ancylostoma eggs per gram of dry weight of feces was determined from each sample. By 1 week after treatment, the mean number of eggs being passed by the treated dogs had dropped from 12,700 to 10 eggs/g of dried feces; there was no apparent change in fecal egg counts for dogs of the control group. At necropsy, the mean number of adult A caninum in dogs of the treated and control groups was 1.3 and 56, respectively; in these naturally infected dogs, efficacy of treatment was calculated to be 97.8%. The mean number of adult Trichuris vulpis recovered in dogs of the control and treated groups at necropsy was 24 and 0, respectively, which yielded treatment efficacy of 100%. Although Uncinaria stenocephala and Toxocara canis appeared also to be removed by use of this dosage, too few dogs were in the study to calculate meaningful efficacies. The milbemycin oxime formulation appeared to have no effect on the cestodes (Taenia pisiformis and Dipylidium caninum) and spirurids (Physaloptera rara) that were present in some dogs.

Important procedural factors in the under-agarose assay for porcine neutrophil migration were identified, and optimal conditions were established. Three factors were tested: the concentration of zymosan-activated serum inoculated into the outer well; the number of neutrophils inoculated into the center well; and the time of incubation of the agarose plates. All factors had a significant (P < 0.0001, 0.0001, and 0.01, respectively) effect on the chemotactic index of porcine neutrophils. The optimal combination of these 3 factors was undiluted zymosan-activated serum as the chemoattractant, 8 x 10(5) neutrophils inoculated into the center well, and 5 hours of incubation. The assay was validated, using standard conditions, and the data were used to predict the number of pigs and/or repetitive assays needed to identify differences among experimental groups.

Cattle heterozygous for deficiency of uridine monophosphate synthase required more breeding services per calving when mated to other heterozygotes than did matings of normal cattle. Gestation length, number of breeding services per calving, and days from breeding to pregnancy examination were monitored on 759 complete gestations, 76 false-positive pregnancy diagnoses, 14 false-negative pregnancy diagnoses, and 413 negative pregnancy diagnoses in a dairy herd between 1983 and 1987. For complete gestations, 15 heterozygote X heterozygote matings required 3.13 +/- 0.37 breeding services per calving, which was significantly more than the 2.05 +/- 0.05 breeding services required for normal X normal matings; gestation length and days from breeding to pregnancy examination were similar between mating types. For false-positive pregnancy diagnoses, females diagnosed pregnant, but subsequently found not to be pregnant, 5 heterozygote X heterozygote matings averaged 51 +/- 23 days of gestation, which was less than the 93 +/- 6 days required for 71 normal matings; services and days from breeding to pregnancy examination were similar between mating types. All false-negative pregnancy diagnoses, females diagnosed not pregnant but later found to be pregnant, were made on cattle with normal matings. For negative pregnancy diagnoses, heterozygous matings averaged 0.3 more breeding services per examination than normal matings.

The protein requirement of Pointer pups fed practical diets was assessed in 3 experiments. Eight-week-old pups required 25.2% protein when fed a combination of corn gluten meal, soybean meal, and meat and bone meal for 2 weeks. However, when a poor-quality poultry by-product meal was substituted for some of the corn gluten meal and meat and bone meal, the requirement increased to 27.5%. This increased requirement was explained by decreased digestibility of the poultry by-product meal diet. Pups fed each of the diets required 18% digestible protein to maximize growth rate. Sixteen-week-old pups were more efficient at utilizing the experimental diets, requiring only 23% crude protein (17.2% digestible protein) to maximize growth rate.

The binding of bovine complement S protein (vitronectin) to Streptococcus dysgalactiae isolates from cattle with mastitis and the S protein's role in streptococcal adherence to bovine epithelial cells were investigated. All 25 clinical isolates of S dysgalactiae interacted with bovine S protein. None of the other streptococcal species tested bound to bovine S protein. The S protein-binding sites were saturable and highly sensitive to trypsin. The binding of bovine S protein to S dysgalactiae isolates was specific and could not be inhibited by other plasma proteins, such as fibronectin, albumin, fibrinogen, alpha 2-macroglobulin, or IgG. Similarly, streptococcal binding of bovine S protein was not influenced by the synthetic peptide Gly-Arg-Gly-Asp-Ser, which constituted the host cell attachment sequence of S protein. In adherence experiments, prior binding of bovine S protein to S dysgalactiae enhanced streptococcal adherence to bovine epithelial cells. The enhancing effects by bovine S protein were abolished when the respective binding sites on the streptococci were digested by trypsin. Thus, bovine S protein could be an important mediator of adherence of S dysgalactiae to bovine epithelial cells.

Opsonized Rhodococcus equi activated the respiratory burst of resident alveolar macrophages (AM) from adult horses in a logarithmic-linear, mass-related manner. The effect of R equi was not significantly different from that of equal masses of opsonized zymosan A. Therefore, R equi does not appear to attenuate the respiratory burst of equine AM. The stimulatory effect of R equi was not reflected by increased production of superoxide anion (O2-), but increased activity of the hexose monophosphate shunt was observed. These results suggest a similarity between the respiratory burst of Am from horses and that of AM from rabbits. We concluded that resident AM from adult horses do not produce O2- concurrently with an increase in activity of the hexose monophosphate shunt when stimulated with either opsonized zymosan A or opsonized R equi. This suggests that O2- is not an important component of the antibacterial defenses of equine AM. Whether equine AM are incapable of producing O2- or require different stimuli to produce it was not determined.

The size of the liver, as well as the situation and diameter of vessels in cattle were determined by use of ultrasonography. Ultrasonographic examinations of the liver were performed on 10 cows 10 times within 2 weeks, using a 3.5-MHz linear transducer on the right side in the 12th, 11th, and 10th intercostal spaces. Dorsal and ventral margin of the liver as well as localization and diameter of the caudal vena cava and the portal vein were determined in each intercostal space. Furthermore, the angle of the liver in the ventral area between the visceral surface and the diaphragmatic surface, the dorsal margin, and the circumference of the gall bladder were determined. The ultrasonographic values of liver size and localization in healthy cows can be used as reference values for the diagnosis of changes in liver size attributable to illness.

Latency and reactivation of pseudorabies virus in swine was studied. Thirty-one pigs were assigned to 5 groups and were given 1 of 4 vaccines; 10 remained unvaccinated controls. All pigs were then challenge exposed with a sublethal dose of virulent pseudorabies virus. One hundred one days after challenge exposure, all pigs were treated with dexamethasone to reactivate the virus. Virus-positive tonsil and nasal mucus isolates were recovered from 29 of the 31 pigs over a 12-day period. Frequency and duration of virus-positivity were significantly (P < 0.05) and consistently lower among vaccinated pigs than among the unvaccinated controls. It was concluded that vaccination before challenge exposure had little or no effect on the rate of establishment of virus latency, but that vaccination reduced shedding after subsequent reactivation of the virus.

Aminoglycoside nephrotoxicosis (AGNT) was induced in ewes by daily SC administration of gentamicin. Changes in urinary indices of renal function during the development of AGNT are reported. Measurements from timed, volume-measured urine samples were made on days 0, 7, and 8 and included creatinine clearance, total excretion (TE) rates of electrolytes (Na, K, Cl, P) and urine volume. Measurements from free-catch urine samples (without volume measurement) were made daily and included fractional excretion (FE) rate of electrolytes, urine osmolality, and urine-to-serum osmolality and urine-to-serum creatinine ratios. With the onset of AGNT, FE rates of Na, K, Cl, and P increased many fold above baseline values (200 X, 4 to 5 X, 6 to 9 X, and 70 to 95 X, respectively, on days 7 and 8), indicating decreased tubular reabsorption or increased tubular secretion. The increased FE rates were not representative of increases in total electrolyte excretion rates. The total excretion of Na (TE(Na)) was mildly increased, TE(K) was decreased, TE(Cl) was unchanged, and TE(P) was significantly increased on days 7 and 8. Abnormal urinalysis results, glucosuria, and increased FE(P) preceded appreciable increase in serum creatinine concentration. Other abnormal urinary indices of renal function coincided with or followed the increase in serum creatinine concentration. Urinary indices may help characterize renal function associated with the disease state, but did not provide early indication of AGNT.