Clinical electromyographic studies were performed in dogs (6 weeks to 5.5 years old) with a degenerative myopathy analogous to Duchenne muscular dystrophy. Spontaneous activity, consisting primarily of complex repetitive discharges (pseudomyotonic discharges), was found in all dogs tested, but was most prominent in dogs greater than or equal to 10 weeks old. Myotonic discharges also were found, but were less frequent. Motor unit potentials were generally abnormally brief and frequently polyphasic. Ulnar nerve conduction velocities determined in two 4-month-old dogs were similar to those of unaffected littermates. It was concluded that canine X-linked muscular dystrophy is a primary myopathic process in which complex repetitive discharges and myotonic discharges are a prominent feature. The basis for this spontaneous activity is not known.

Twelve-week-old specific-pathogen-free pigs were inoculated deep in the bronchi with Haemophilus (Actinobacillus) pleuropneumoniae strain 13261 in doses ranging from 8 x 10(1) to 9 X 10(7) colony-forming units (CFU). Pigs that survived infection were euthanatized and examined 48 hours after inoculation. The relationship between dose and severity of disease was evaluated clinically and the weight of pneumonic lesions was compared. The relationship between infection dose and weight of pneumonic lesions proved to be unimodal and not linear. Inoculation of 10(4) CFU of strain 13261 resulted in severe pneumonic lesions and mortality of 29%. In contrast, death was not observed after inoculation with 10(6) CFU of strain 13261 and pneumonic lesions were less severe (P < 0.05). An infective dose of 10(3) CFU induced pneumonic lesions that tended (not statistically significant) to be less severe than those induced by a dose of 10(4) CFU. The peak fever response in all infected pigs was observed from 6 to 12 hours after inoculation. Leukocytosis developed within 12 hours after inoculation, because of an increase of neutrophilic granulocytes. Thereafter, WBC count decreased owing to lymphopenia. Serum iron concentration decreased 80% after inoculation, and zinc concentration decreased 54%.

This study compared the short-term clinical and pathologic effects of spiral and total ring prostheses, applied to the cervical and thoracic portions of the trachea of dogs via a combined intercostal thoracotomy and ventral cervical midline approach. The effect of intraluminal placement of synthetic monofilament nonabsorbable suture also was evaluated. Eleven small-breed dogs were randomly allotted to 3 groups. Group 1 (n = 3) were controls that had been treated by sham operation, group 2 (n = 4) had polypropylene spiral prostheses applied to the cervical and thoracic portions of the trachea, and group 3 (n = 3) had total ring prostheses applied to the cervical and thoracic portions of the trachea. All dogs were euthanatized and necropsied 8 weeks after surgery. Clinical complications were minimal and limited to mild, short-term lameness and coughing. Three and 6 weeks after surgery, radiographs were within normal limits in all dogs. Tracheoscopy confirmed maintenance of tracheal lumen diameter and integrity of the mucosal epithelium in all dogs. Gross and microscopic postmortem findings were similar in groups 2 and 3. Mild adhesions were present between prostheses and adjacent structures. Similar adhesions were present where prostheses had been applied and subsequently removed in group-1 dogs. Histopathologic abnormalities included mild to moderate adventitial and periprosthetic fibrosis and mild adventitial inflammation associated with polypropylene spiral prostheses and total ring prostheses. The majority (70%) of intratracheal sutures evaluated were covered by microscopically normal ciliated mucosal epithelium by 8 weeks after surgery. Polypropylene spiral prostheses and total ring prostheses applied to the cervical and thoracic portions of the trachea of dogs in the manner described appear to be tolerated well and produce a minimal tissue response over the study period.

Two hundred seventy-eight strains of Salmonella typhimurium isolated from 1973 to 1981 from animal sources in New York State were studied for possible virulence determinants and for a serotype-specific plasmid possibly linked with virulence. Of the strains, 98% possessed type-1 fimbriae. All strains possessed flagella and were motile. One hundred twenty-three strains (44%) treated with mitomycin C tested positive for the cholera-Escherichia coli heat labile family of toxins by a kinetics-based ELISA; when treated with mitomycin C and extracted with polymyxin B, 249 (90%) were positive in the kinetics-based ELISA. All strains were negative in the Biken Test. A smooth cell wall was found in 99% of the strains. Sixty-one percent (169) of the strains had a 62-Md plasmid. Seventy-six (27$%) of the strains had detectable plasmids ranging in size from 1 to 124 Md.

Restriction endonuclease digestions were performed on plasmids purified from Moraxella bovis isolates GRS, Newport, and IBH64. It was determined from single and double digestions of plasmid DNA that GRS and Newport isolates carried 3 large plasmids having molecular sizes of 43.8, 41.3, and 32.8 kilobases (kb). Digestion of the 3 large plasmids and restriction endonucleases Hae III, HindIII, Nde I, and Ava I strongly indicated that these isolates shared structurally identical large plasmids. Timed single digestions with Ava I revealed that the IBH64 isolate carried 2 large plasmids having molecular sizes of 45 and 32.8 kb. The 32.8-kb plasmid was the only large plasmid that appeared to be shared by all 3 M bovis isolates. Two isolates, Newport and IBH64, carried small plasmids in addition to the large plasmids. Restriction maps were constructed for the 43.8-, 41.3-, and 32.8-kb plasmids.

The restriction endonuclease digestion DNA patterns from Brucella abortus strains 19 and 2308 were examined with 11 restriction enzymes (AvaI, BamHI, BglII, BstEII, DdeI, EcoRI, HindIII, KpnI, PstI, XbaI, and SalI)). The DNA electrophoretic banding patterns between the strains were highly similar, using this restriction enzyme analysis. Differences were not discernable between B abortus strains 19 and 2308 in any of the restriction banding patterns examined. Methylation at CCGG or GATC sites was not detectable on the basis of digestion with isoschizomers (HpaII and MspI, and DpnI, Sau3AI and MboI). Homology between B abortus strains 19 and 2308 was assessed, using solution-hybridization techniques followed by S1 nuclease assays. Results of these reassociation experiments indicated 98.6 to 99.3% homology between B abortus strains 19 and 2308 with 13.5 to 18.6% homology between B abortus (strains 19 and 2308) and the E coli HB101 control. We concluded that any DNA differences between the 2 B abortus strains are small and will require analysis at the DNA sequence level.

Sixteen primiparous sows were bred and fed either a control ration (n = 8) or a diet containing purified zearalenone (n = 8; 1 mg/kg of body weight) from days 7 to 10 after breeding. On day 7 after breeding, the jugular vein of each sow was cannulated and blood was collected at 20-minute intervals for 4 hours before feeding and 4 hour after feeding. On day 10 after breeding, blood samples were collected from 4 control sows and 4 zearalenonefed sows at 20-minute intervals for 4 hours before collection of blastocysts. A similar blood sampling schedule was followed for the remaining 4 control and 4 zearalenone sows on day 14 after breeding. On day 10 after breeding, spherical blastocysts were recovered from all control sows and from 3 of 4 zearalenone-treated sows. Average diameter of blastocysts from zearalenone-treated sows were similar to that of control sows. On day 14 after breeding, blastocysts were recovered from all control sows and 3 of 4 zearalenone-treated sows. Blastocysts from the control sows were filamentous, whereas blastocysts from zearalenone-treated sows were fragmented and contained foci of necrosis. Incidence of luteinizing hormone (LH) secretory spikes per sow was less (P less than 0.01) in zearalenone-treated sows (0.25 +/- 0.25/4 h) than control sows (1.75 +/- 0.25/4 h) on day 10 after breeding. Incidence of follicle-stimulating hormone (FSH) secretory spikes was simillar (P = 0.45) among treatments on days 7, 10, and 14 after breeding. Mean serum concentrations of LH were less on day 10 (P = 0.07) and day 14 (P less than 0.01) in zearalenone-treated sows than in control sows (3.3 +/- 0.2 ng/ml vs 6.2 +/- 1.3). These data indicate that administration of zearalenone on days 7 to 10 after breeding altered secretory patterns of serum LH during days 10 and 14 after breeding, which may have contributed to the death of blastocysts by day 14 after breeding.

Lesions in 32 calves that died or were euthanatized during the course of severe natural infection with bovine respiratory syncytial virus (BRSV) are described. All calves had been dyspneic for 1 to 2 days. At necropsy, lesions that could be related to dyspnea included congested and cyanotic mucosae and widespread petechiae. The lungs had various lesions in the cranioventral (CV) and caudodorsal (CD) portions. The CV portion of the lungs was consolidated, firm, and edematous. Histologically, the main characteristic was degenerative, necrotic bronchiolitis, with few syncytial cells. Signs of repair, such as epithelial hyperplasia, fibrosis, and bronchiolitis obliterans, often were observed. The CD portion of the lungs was markedly distended, owing to severe edema and emphysema. Bronchiolar lesions were lacking in the CD portion. In 14 calves, hyaline membranes were seen in the CV and CD portions. Results of immunofluorescence for BRSV were positive in 24 calves, but only in the CV portion of the lungs. The calves had variable concentrations of BRSV-specific IgG1 and IgM in serum, lung lavage fluid, or both. The BRSV-specific IgA, on the contrary, was seldom detected. Thus, 2 discrepancies existed. Although the clinical picture appeared to be acute, bronchiolar lesions and serotest results suggested infection of longer duration. Also, although virus and viral cytopathologic features were detected only in the CV portion of the lungs, the CD portion had extensive lesions that consisted of emphysema and edema.

Nutritional alterations were evaluated in 9 horses before surgery and 3 weeks, 3 months, and 6 months (4 total trials) after sham operation (group 1; n = 3) or extensive large colon resection (group 2; n = 6). Feed and fecal analyses were performed to determine apparent digestion of dry matter, organic matter, crude protein, calcium, phosphorus, magnesium, potassium, manganese, zinc, copper, and iron, and true digestion of dry matter, organic matter, crude protein, total plant cell wall, hemicellulose, cellulose, and lignin. Additional fecal and metabolic variables included the percentage of fecal water (water in the feces), total fecal water, metabolic organic matter, metabolic crude protein, and metabolic nitrogen. A CBC and standard series of biochemical tests were performed. Large colon resection decreased (P less than 0.05) the true digestion of dietary crude protein and cellulose and apparent digestion of phosphorus, and it increased the fecal metabolic matter and water loss. Total fecal output increased 45% and total fecal water increased 55%. Phosphorus digestion was decreased (P less than 0.05) in group-2 horses, but effects of this were not detected on analysis of blood variables or on physical examination. Nevertheless, after extensive large colon resection, horses can regain body weight lost after surgery and have no overt physical changes when fed an alfalfa pellet diet that meets greater-than-maintenance requirements. Ad libitum water access is suggested, because these horses may have to consume 2 gal/day more than would normal horses.

Live Pasteurella haemolytica biotype A, serotype 1 isolates (n = 3) and Escherichia coli K-12, strain W3110, were reacted with bovine pulmonary lavage cell (PLC) suspensions. The comparative effects of the different bacteria on the functional and metabolic activity of alveolar macrophages (AMO) in the PLC suspensions were assessed simultaneously by use of 51Cr release, luminol-dependent chemiluminescence (LDCL), and AMO bactericidal assays. The bovine PLC reponsed differently to E coli, than to the 3 P haemolytica isolates in each of the 3 experimental test systems; however, responses to each of the P haemolytica isolates were not found to be significantly different. Unopsonized live P haemolytica cells adversely affected the functional and metabolic response of PLC, whereas there was no evidence of a cytotoxic (cytocidal) influence of E coli. A difference in 51Cr release for reaction mixtures containing E coli and P haemolytica was not detected at zero time; however, at each subsequent time, reaction mixtures phagocytically stimulated with P haemolytica had significantly increased amount of 51Cr release (P less than 0.05), compared with those mixtures containing E coli. Bovine AMO in the PLC suspensions were able to effectively kill E coli in vitro, but were unable to prevent survival and subsequent growth of P haemolytica. The luminol-dependent chemiluminescence profiles for reaction mixtures phagocytically stimulated with E coli provided evidence of sustained production of oxygen radicals with antimicrobial capabilities by bovine AMO in the PLC. Production of these highly reactive antimicrobial oxidants appeared initially in cultures containing P haemolytica but, subsequently, their production declined precipitously and ceased altogether.