The efficacy, safety, and compatibility of fenbendazole (FBZ) and clorsulon (CLN) were tested after oral administration of label recommended and of higher (5 x) dosage rates to calves naturally infected with gastrointestinal nematodes and Fasciola hepatica. Results for 42 calves allotted to 4 treatment groups indicated a similar efficacy against mature F hepatica by FBZ (5 mg/kg of body weight) and CLN (7 mg/kg) in a combined oral suspension, compared with CLN (7 mg/kg) alone (100 vs 99% reduction). A lesser efficacy was observed against immature flukes (88.6 and 84.9% reduction, respectively). Calves given 25 mg of FBZ/kg and 35 mg of CLN/kg had nearly complete reduction of both mature (99.6%) and immature flukes (99.1%). Fasciola egg counts were reduced by > 99.5% in all treated groups. Against Ostertagia ostertagi, the percentage of efficacy of the combined FBZ (5 mg/kg) and CLN (7 mg/kg) treatment was 94.3% against adults and 81.3% against inhibited larvae. Efficacy against all other nematodes was 100%, except against Cooperia spp adults (98.3%) and immature Oesaphagostomum radiatum (88.0%). At 5 x dosage rates for FBZ and CLN, percentage of removal of adults and inhibited larvae of O ostertagi was 99.3 and 99.0%, respectively, and 99 to 100% for other nematodes. Results indicate that FBZ and CLN are compatible when mixed together and administered as an oral suspension to cattle and that the efficacy is similar to that of the drugs individually. On the basis of further results, we suggest that summer treatment may be superior in preventive value for gastrointestinal nematodes and F hepatica, compared with spring treatment, because of seasonal infection dynamics of the major cattle parasites in Louisiana.

A group of 48 crossbred steers (approx 250 kg each) were used to determine the effects of various diets and treatments on serum prolactin concentrations and rectal temperatures. The steers were randomly assigned to groups fed the following: (1) endophyte fungus-infested fescue hay; (2) ammoniated endophyte fungus-infested cattle industry hay; (3) endophyte fungus-infested fescue hay plus 1 g of thiabendazole (TBZ)/9.1 kg of body weight at 7-day intervals; (4) ammoniated endophyte fungus-infested fescue hay plus 1 g of TBZ/9.1 kg at 7-day intervals; (5) ground Bermuda grass hay; and (6) endophyte-fungus-free fescue hay. Blood samples for prolactin determinations and rectal temperatures were obtained biweekly beginning on week 3 and continuing through week 9. A significant correlation (P < 0.05) between low prolactin concentrations and high rectal temperatures in cattle eating endophyte-infested fescue hay was determined; however, as the prolactin concentrations approached normal (control animal) concentrations, this relationship between serum prolactin and rectal temperatures was not observed. Two antifungal agents used in this experiment (thiabendazole and ammonia) appeared to have different effects on the variables measured. Thiabendazole had no significant effect on prolactin concentrations or rectal temperatures of cattle ingesting endophyte-infested fescue hay, whereas ammoniation of this hay induced significantly higher (P<0.05) prolactin concentrations and lower rectal temperatures than in steers receiving only endophyte-infested fescue hay. Therefore, ammonia may be valuable not only as an aid in determining the cause of the fescue problem but also as a practical solution to some of the fescue-related economic problems in the cattleindustry. Also, prolactin concentrations may be valuable in diagnosing fescue-related problems.

Brain stem auditory-evoked potentials (BAEP) were recorded in 4 dogs to analyze the relationship between acoustic stimulus intensities and peak latencies of each wave, and to investigate the relative effects of xylazine-atropine-ketamine, and xylazine-atropine-pentobarbital combinations and the time-course effects of the latter 2 drug combinations on BAEP. Click stimulations fixed at a stimulus rate of 10/s and a frequency of 4 kHz were delivered at intensities ranging from 10- to 110-dB sound pressure level (SPL) in 10-dB steps for analyzing the relationship between the acoustic stimulus intensities and the peak latencies and at an intensity of 110-dB SPL for investigating the effects of the sedative and the anaesthetic drug combinations and their time-course effects on BAEP. Waves I and VI were identified with stimulus intensity of greater than or equal to 50-dB SPL. Wave VII was observed in some records, but was excluded from statistical analysis. As intensity was increased from 50- to 110-dB SPL, the latency decreased for all waves during xylazine-atropine-ketamine anesthesia. There were no statistically significant differences in the peak latencies of each wave in BAEP among xylazine-atropine, xylazine-atropine-ketamine, and xylazine-atropine-pentobarbital combinations 20 minutes after drug administration, except that the latency of wave VI during xylazine-atropine sedation was significantly (P < 0.01) shorter than that detected during xylazine-atropine-ketamine or xylazine-atropine-pentobarbital anesthesia. There were no significant changes in peak latencies of waves I, II, III, V, and VI for 90 minutes after administration of the xylazine-atropine-ketamine combination and for 120 minutes after administration of the xylazine-atropine-pentobarbital combination. It was concluded that BAEP did not change over time after xylazine-atropine-ketamine or xylazine-atropine pentobarbital administration.

The vascular patterns to pelvic limb muscles were studied in 6 dogs (12 limbs) to identify muscles most suitable for transposition in the treatment of large wounds. Gross dissection of injected specimens and angiography were used to identify the vascular pedicles. The vascular pedicles to several muscles were generally consistent, and any variations would not interfere with most muscle transfers. The cranial part of the sartorius, gracillis, semitendinosus, and rectus femoris muscles were identified as suitable candidates for transfer. The caudal part of the sartorius, cranial tibial, and long digital extensor muscles have segmentalized vascular patterns that would limit its arc of rotation.

Genital tracts from 15 cows with catarrhal and purulent inflammation of the uterus and uterine tubes, cystic hyperplasia of the endometrium, or hydrosalpinx were evaluated by use of scanning electron microscopy to determine epithelial changes associated with these conditions. Uterine epithelium was revealed to be easily damaged, even in the course of mild inflammation, whereas epithelium of the uterine tube was more resistant.

Plasmid profiles were compared between nonpiliated and piliated forms of Moraxella bovis isolates. The piliated form of M bovis isolate IBH64 contained 1 fewer plasmid than did the nonpiliated form. Piliated and nonpiliated cells of IBH64 contained plasmids having molecular size of 45, 32.8, 4.9, and 4.6 kilobases (kb). Single- and double-restriction endonuclease digestion by Ava I and Nde I indicated that the size of the additional plasmid carried by the nonpiliated form of IBH64 was approximately 43.6 kb. The M bovis isolates, Newport and GRS, contained the same number of plasmids in either their piliated or nonpiliated form.

Results of a prospective serologic and virologic study of ruminant livestock in Central America and the Caribbean islands revealed bluetongue virus (BTV) to be enzootic in the 9 countries participating in the study. Bluetongue virus serotypes 1, 3, 6, and 12 were isolated from sentinel animals. To the authors' knowledge, these are the first isolations of BTV from the region studied and the first isolations of these serotypes in the Western Hemisphere. Clinical disease attributable to BTV infection was not observed in sentinel animals. The incidence pattern, with respect to age and geographic location, was determined. The need to evaluate the epizootiologic features of arthropod-borne viruses (arboviruses) on a regional ecologic basis is stressed.

Ceftiofur hydrochloride was tested for effectiveness against induced colibacillosis in neonatal swine. In this model, pigs < 12 hours old were inoculated via stomach tube with a virulent, K99+, nalidixic acid-resistant strain of Escherichia coli. Six hours after challenge exposure, 1 dose of ceftiofur was administered either IM or orally in experiment 1 and orally only in experiment 2. Mortality, shedding of bacteria, fecal consistency scores, and body weight changes were monitored for 10 days. In experiment 1 (n = 383 pigs), all treatments at dosage that ranged between 0.5 and 64.0 mg of ceftiofur/kg of body weight significantly (P < 0.001) reduced mortality, bacterial shedding, and diarrhea and increased weight gain, compared with findings in untreated controls. There were no detectable differences between oral and IM routes, except that there was greater reduction in bacteria shedding associated with the oral route of administration. In experiment 2 (n = 505 pigs), ceftiofur was administered orally either once at 6 hours after challenge exposure or twice at 6 and at 48 hours after the first dose. Dosage of ceftiofur was 0, 5, 10, 20, 30, or 60 mg/kg administered once, or half the same dose was administered at each of 2 times. At the optimal dosage (10 mg/kg), a single dose was as effective as 2 doses. The single administration at all dosages reduced mortality, bacterial shedding, and diarrhea scores and increased body weight gain, compared with findings in untreated pigs (P < 0.01). In this induced infection model, the optimal treatment dosage was determined to be 10 mg/kg administered once.

Biological effects of staphylococcal protein A (SPA) immunotherapy were studied in 5 viremic and 6 nonviremic cats with induced FeLV infection and in 6 control cats. The SPA therapy neither reversed FeLV viremia nor resulted in consistent improvement in humoral immune responses to FELV antigens. However, SPA immunotherapy induced a proliferative response in bone marrow granulocytic lineage, possibly resulting in expression of FeLV-free mature neutrophils in the blood. Seemingly, viral burden and chemiluminescent responses were reversed in viremic cats during SPA immunotherapy.

A superovulatory and surgical protocol was developed for recovery of bovine zygotes. Holstein cows and heifers were given follicle-stimulating hormone and cloprostenol to induce superovulation. Surgical cannulation and lavage of the uterine tube was performed 40 to 48 hours after the start of standing estrus. In general, cows had more corpora hemorrhagica than did heifers, but a higher percentage (P < 0.05) of ova recovered from cows were infertile. Several heifers were subjected to the procedure twice, and embryo recovery rates were equivalent both times.