The role of silage feeding in the origin of an epizootic of encephalitic listeriosis in a sheep flock was investigated by use of a new direct Listeria-selective isolation and enumeration medium, in combination with serotyping and phage typing. The silage contained high numbers (about 10(6) cells/g) of a L monocytogenes strain indistinguishable with respect to serovar and phagovar from that isolated from the brains of sick sheep. These results provided unambiguous bacteriologic evidence of the epidemiologic link between silage consumption and listeriosis in ruminants.

Ten controlled tests were done between 1972 and 1989, in lambs on pasture, evaluating activity of fenbendazole (FBZ; 5 mg/kg of body weight), oxfendazole (OFZ; 3.5 and 10 mg/kg), oxibendazole (OBZ; 10 mg/kg), pyrantel pamoate (PRT; 25 mg of base/kg), and thiabendazole (TBZ; 44 and 50 mg/kg) against natural infections of helminths, with emphasis on 2 strains (A and B) of Haemonchus contortus. Strain A was phenothiazine-susceptible and strain B was phenothiazine-resistant when isolated in 1955. For approximately 10 years prior to these tests, sheep infected with both strains had been treated periodically each year with several compounds, including thiabendazole, which was used many more times than the other drugs. For this study, 4 (FBZ, OFZ, OBZ, and PRT) of the 5 compounds were evaluated in either 1 or 2 controlled tests. The fifth compound, TBZ, was used for 5 tests. Strain A H contortus was resistant to TBZ for all years tested, but more susceptible to FBZ, OFZ, OBZ, and PRT. Overall, strain B was susceptible to TBZ (with a few exceptions), and also to FBZ, OFZ, OBZ (activity less on immature forms), and PRT. Other abomasal parasites (2 species of Ostertagia and 3 of Trichostrongylus) were found in low numbers, but removal overall was good for the compounds tested. Trichostrongylus axei, found in higher numbers than species of Ostertagia and other species of Trichostrongylus, were effectively removed by all compounds in most cases. Activities of TBZ and PRT were also evaluated against several species of intestinal helminths, most of which were found in low numbers. Cooperia curticei were inconsistently removed by TBZ, but activity of PRT was effective. Both compounds were active on mature Nematodirus spathiger, but TBZ had variable activity on immature forms. Strongyloides papillosus were effectively removed by TBZ. Other parasites found in lower numbers than the aforementioned 3 species were Capillaria spp, Trichuris spp, and Oesophagostomum columbianum; removal was variable for both drugs.

Isoelectric focusing was performed on the soluble proteins of whole-body and excretory-secretory products (ESP) of Fasciola hepatica and Fascioloides magna. Adult F hepatica flukes were recovered from experimentally infected sheep and ESP obtained from the flukes; portions of liver were cut and frozen at -70 C. Fascioloides magna adults were collected from naturally infected white-tailed deer and ESP obtained; portions of liver were collected from noninfected white-tailed deer. Adult flukes and their host tissues were homogenized and centrifuged; protein concentrations with their ESP were determined and adjusted to < 2.50 mg/ml. Seven ESP samples from F hepatica and 1 from Fascioloides magna were subjected to isoelectric focusing with the 2 species of fluke and their respective host liver homogenates. After separation, gels were stained with silver and scanned on a laser densitometer. Protein banding patterns of the 2 species of flukes were dissimilar. In the pH range of 3.5 to 9.6, the body protein had approximately 30 peaks and ESP about 23 peaks in both species. Overall banding patterns of the body protein and ESP of both species were distinct from those of respective host tissues. Of the peaks reported as dominant, 3 of the body protein and 2 of ESP were shared between the 2 species. Fascioloides magna had more dominant peaks than F hepatica. This technique of soluble protein isoelectric focusing is simple and reproducible, and the 2 fluke species can easily be differentiated by this technique, as well as by morphologic characteristics.

Chickens in a low-stress environment (heterophil/lymphocyte ratio 0.31) were given feed containing 30, 40, or 60 mg of corticosterone/kg of feed for 0.5 hour. Between 0.5 to 12 hours later, chickens were exposed to Escherichia coli via the air sac route. For each dose of corticosterone, there was an untreated control group that was exposed to E coli via the air sac route. The prevalence of pericarditis was reduced from 78 to 7% between 2 and 4 hours after exposure. Resistance was associated with heterophil/lymphocyte (H/L) ratios greater than 1.04. Peak H/L ratios correlated positively with amount of corticosterone in the feed. In one experiment, chickens were inoculated IV with sheep erythrocytes at various times after consumption of feed containing corticosterone. Suppression of antibody responsiveness was most pronounced 4 hours later. Antibody responsiveness correlated positively with lymphocyte numbers. Histologic examination of air sacs was made following euthanasia at various times after E coli exposure. Lesions observed in control chickens included: edema at 0.5 hour, beginning of heterophil infiltration at 1 hour, increased edema and heterophil infiltration at 2 hours, and severe edema and heterophil infiltration at 4 hours. Lesions were not observed in chickens that had been given feed containing 40 mg of corticosterone/kg of feed.

Histomorphometric and scanning electron microscopic analyses were carried out on 74 embryos and fetuses and 20 sheep (early postnatal to adult age). Histodifferentiation of the rumen took place at 33 days of fetal fife. Ruminal pillars were observed at 42 days, and at 61 days, ruminal papillae appeared as evaginations of the epithelial stratum basale. Neutral mucopolysaccharides first appeared in epithelial cells at 46 days of fetal life; thereafter, numbers decreased gradually and subsequently stabilized in postnatal life. Acid mucopolysaccharides, mucins, and mucoid compounds were not detected. Age and diet were recognized as factors that determine the structure of the ruminal mucosa. Growth curves and formulas were set out for each tissue layer.

We determined the position, dimensions, and structure of the kidneys, ureters, bladder, and urethra of 62 female sheep by use of ultrasonography. A 5.0-MHz convex transducer was placed over the right flank to examine the kidneys, and a 5.0 MHz-linear transducer was used to examine the bladder and urethra transrectally. All examinations were performed on sheep in standing position. The left kidney was 7.1 to 8.9 cm long, 3.4 to 5.5 cm wide, and 3.3 to 4.7 cm deep. Diameter of the parenchyma and renal sinus of the left kidney ranged between 1.1 and 1.9 cm and 1.1 and 2.0 cm, respectively. Circumference of the medullary pyramids varied between 2.1 and 3.3 cm. Similar ultrasonographic measurements were obtained for the right kidney. The diameter of the bladder varied between 0.3 and 6.9 cm in 96.8% of the sheep. The diameter of the bladder could not be determined in 32% of the sheep because it was > 10 cm, and, therefore, was beyond the penetration depth of the scanner. The only part of the urethra that could be ultrasonographically visualized was the internal urethral orifice. It had diameter between 0.1 and 0.2 cm. The ureters could not be ultrasonographically visualized in any of the sheep examined. The urinary tract of 8 sheep was examined 10 times within 2 weeks to examine whether measurements were reproducible. The interassay variation coefficient determined ranged from 3.1 to 31.8%, although for most variables, it ranged between 5 and 11%. Measurements for the length and width of the kidneys had the smallest interassay variation coefficient, whereas values obtained for diameter of the bladder and urethra, as well as thickness of the bladder, had the largest. It was concluded that the ultrasonographic findings described in this study can be used as references for diagnosis of morphologic changes in the kidneys, bladder, and urethra of sheep.

A double-antibody sandwich ELISA for detection of antibodies directed against the exotoxin of Corynebacterium pseudotuberculosis, the cause of caseous lymphadenitis (CL) in small ruminants, was developed. A concentrated exotoxin was used. For interpretation of ELISA results, these sera were tested: sequentially obtained sera of C pseudotuberculosis-inoculated goats and sheep that were monitored for 68 weeks; sequentially obtained sera from 80 goats of 3 flocks with CL; sera from 652 goats of 7 flocks without CL; sera from 160 sheep of 4 flocks without CL; and 2,265 caprine and 208 ovine sera submitted for diagnostic testing. Data regarding the infection status and history of 10,454 of the 23,302 animals were collected after testing; most of these were goats that had been part of a CL control program. Specificity and sensitivity of the ELISA were nearly 100%. Subsequently, 31,978 animals from which no data on infection status of flocks had been collected were then tested. It was concluded that the ELISA is a useful diagnostic test for CL eradication programs. Sera with doubtful or inconclusive ELISA results were examined by use of immunoblot analysis. Proteins from C pseudotuberculosis culture supernatant were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and blotted onto nitrocellulose. Six proteins with molecular mass of 68, 65, 39, 38, 31, and 29 kDa reacted with sera from goats and sheep with experimentally induced or naturally acquired infection. Immunoblot analysis was valuable in classifying sera with doubtful or inconclusive results by ELISA.

Changes in the common bile duct that contained adult Fasciola hepatica of sheep were evaluated by light (LM) and scanning electron microscopy (SEM). Nine ewes were inoculated with F hepatica metacercariae and necropsied 18 weeks after inoculation. The proximal portion of the common bile duct (CBD) that contained adult flukes was recovered and examined by Lm and SEM. The CBD from 2 noninoculated ewes were used for control. On gross examination, CBD were markedly large because of the adult flukes, which were free in the lumen of the ducts. Extensive hemorrhage was not found either in intrahepatic or in extrahepatic bile ducts of any sheep. Histologic examination revealed changes, such as villous hyperplasia and hypertrophy of the epithelium; cell infiltration, predominately with eosinophils or macrophages; and arterial intimal proliferation. By SEM, the epithelial surface of the CBD appeared intact. Villous hyperplasia and hypertrophy of the epithelium observed by LM was clearly seen by SEM. Epithelial damage, seen as small areas of denuded surface by LM and SEM, was confined to a few areas of the mucosa. Lack of extensive hemorrhage and confined epithelial damage were evaluated relative to the mode of feeding of adult flukes.

Analyses of the fibers in the prepubic tendon of the horse and ruminants have shown that it is composed of the crossed and uncrossed tendons of origin of the pectineus muscles, the pelvic tendons of the rectus and obliquus abdominis muscles, and the tendons of origin of the cranial parts of the gracilis muscles. Pelvic attachments of the linea alba and the yellow abdominal tunic are incorporated in it. It is not a transverse ligament, and it is not homologous to the human superior (cranial) pubic ligament. The dog differs in 4 respects: (1) the pectineus tendons do not cross, but each originates from the pubic bone of the same side; (2) an iliopubic cartilage is intercalated in the prepubic tendon on each side at the junction of the pectineus tendon and the abdominal and pelvic tendons of the external oblique at the caudal angle of the superficial inguinal ring; (3) in some dogs, the caudal border of the aponeurosis of the transversus abdominis joins the prepubic tendon; (4) the gracilis tendon does not extend to the prepubic tendon. The clinical anatomy was described, illustrated, and compared between species. Conflicting descriptions in the literature were discussed and resolved by new approaches to the dissection. Studies of the inguinal region in the cat and pig were reviewed. A table of nomenclature is included.

Sixteen nonsibling sheep, approximately 12 months old, that were raised in a helminth-free environment, were used for 2 protection studies 6 months apart. Sheep were vaccinated weekly for 5 weeks by IM injection of fibrinogen-degrading proteins derived from the intestinal tract of adult Haemonchus contortus. Ten days after the last vaccination, sheep were given 2,500 infective H contortus larvae by intraruminal injection. Vaccinated sheep produced specific antibodies, and were protected from the worm challenge. Significant differences in mean fecal worm egg counts for 56 days after worm challenge, in mean numbers of H contortus worms, and female fecundity ratios at necropsy were detected in vaccinated sheep, compared with those in control sheep. These data suggest that the fibrinogen-degrading proteins have a protective role in vaccination of sheep against H contortus.