Isolation and association of Escherichia coli AIDA-I/STb, rather than EAST1 pathotype, with diarrhea in piglets and antibiotic sensitivity of isolates.

To identify emerging Escherichia coli that have the potential to cause diarrhea in pigs, the prevalence of E. coli pathotypes was determined among 170 and 120 isolates from diarrheic and nondiarrheic piglets, respectively. The isolates were tested for F4, F5, F6, F18, and F41 fimbriae, for E. coli attaching and effacing (EAE), porcine attaching and effacing-associated (Paa), and adhesin involved in diffuse adherence (AIDA-I) factors, for LT, STa, STb, and enteroaggregative heat-stable (EAST1) enterotoxins, and for Shiga toxins (Stxl, Stx2, and Stx2e), using DNA hybridization and polymerase chain reaction. All isolates were O-serotyped and tested for antibiotic resistance against 10 drugs. Seventeen different pathotypes, accounting for 40.0% of the isolates, were recovered from diarrheic piglets. The main pathotypes included EAST1 (13.5%), F4/LT/STb/EAST1 (6.5%), AIDA-I/STb/EAST1 (4.1%), F5/STa (2.9%), EAE/EAST1 (2.9%), and AIDA-I/F18 (2.3%). Only 3 pathotypes, EAE (11.7%), EAST1 (10.8%), and EAE/EAST1 (3.3%), were recovered from nondiarrheic piglets. Paa factor was detected in 8.8% and 7.5% of isolates from diarrheic and nondiarrheic piglets, respectively, and always was associated with other virulence determinants. Overall, 22.9% of isolates from diarrheic piglets appeared to be enteropathogens: enterotoxigenic E. coli (11.7%), enteropathogenic E. coli (3.5%), and E. coli isolates (3.0%) for which none of the above adherence factors was detected. Pathotypes AIDA-I/STb/EAST1 and AIDA-I/STb were isolated only from diarrheic piglets and accounted for 4.7% of isolates. Strains of these pathotypes induced diarrhea when inoculated into newborn colostrum-deprived pigs, in contrast to an isolate positive only for EAST1, which did not induce diarrhea. Antibiotic sensitivity test showed that isolates of the AIDA-I/STb/EAST1 and AIDA-I/STb pathotypes were the only strains sensitive to enrofloxacin, gentamicin, neomycin, and trimethoprim-sulfamethoxazole. This study showed that at least 20.5% of isolates from diarrheic piglets appeared to be associated with AIDA-I/STb pathotype and that EAST1 pathotype is probably not an important marker for diarrhea in piglets.     

A Survey of Disease Conditions in Adult and Feeder Sheep in Saskatchewan

A survey was carried out to identify disease conditions occurring in adult and feeder sheep in Saskatchewan. Necropsies were performed on 50 adult sheep submitted to the Western College of Veterinary Medicine during the period July 1976 to June 1977 and data were assembled from necropsy records of sheep submitted between January 1975 to December 1976. The diseases encountered were briefly described. Conditions of the respiratory and digestive systems were the most significant as causes of mortality. Burdens of helminth endoparasites were generally low. In the flocks included in the necropsy survey, annual mortality among adult and feeder sheep was estimated to be three percent.     

Risk of after-hours visits to an in-hospital food animal service by species

Computer records were accessed documenting in-hospital accessions to the food animal service maintained by the University of Missouri, College of Veterinary Medicine between January 1, 2001 and December 6, 2004. For each species category, the prevalence and relative risk (RR) of after-hours admission were calculated. The prevalence of after-hours visits varied from 0.040 for swine to 0.234 for South American camelidae. Using cattle as a reference level, the relative risk for an after-hours admission was decreased in swine (RR = 0.51) and increased in South American camelidae (RR = 3.04) and sheep or goats (RR = 1.66). The likelihood of an after-hours admission differed significantly among groups.     

Prevalence of maedi-visna infection in culled ewes in Alberta

Maedi-visna (MV) is a relatively common chronic infection of sheep in North America resulting in economic loss to the sheep industry. The objectives of this study were to: 1) measure the prevalence of MV infection in culled ewes in Alberta, by histologic examination (lungs and udder) and serologic testing using an agar gel immunodiffusion (AGID) test, 2) examine any geographic differences in its prevalence in the province, 3) evaluate the level of agreement between histopathologic examination and serologic testing, 4) grade the lesions and correlate the serologic results with the presence of severe histological lesions, and 5) correlate the presence of histological lesions in the lungs and udder in the same animal. Based on histologic findings, the prevalence of MV was 26.8%, compared with 13.0% using serologic testing. There were no significant geographical differences in prevalence, fair agreement (kappa = 42.0%) between histopathologic and serologic results, and poor agreement (kappa = 11.5%) between the presence of lung and udder histological lesions within the same animal. This study indicates that MV is relatively common in culled ewes in Alberta, with no significant geographic variation. The poor sensitivity of the AGID test, compared with histologic examination, should be taken into consideration when interpreting serologic results.     

Indigofera spicata (creeping indigo) poisoning of three ponies

Three ponies continuously grazed a pasture containing an estimated 24% Indigofera spicata (wet weight basis) for 4–6 weeks in April and May 2004. They developed ataxia, paresis, depression, muscle fasciculations, dysphagia, ptyalism and halitosis. Two also developed corneal opacity. One pony recovered with supportive treatment, but the other two were euthanased and necropsied. Neuropathology was not present in either case, but both livers had periacinar and periportal lymphocytic infiltrations and hydropic degeneration of mid‐zonal hepatocytes, with mild to moderate periacinar necrosis also evident in one. The I. spicata contained 2.66 mg 3‐nitropropionic acid (3‐NPA)/g dry matter and 1.5 mg indospicine/g dry matter. Indospicine, but not 3‐NPA, was detected in serum from both of the euthanased ponies and indospicine was detected in heart, liver and muscle from the one pony in which this assay was performed. The clinical syndrome closely resembled ‘Birdsville horse disease’ caused by I. linnaei and was similar to that reported in horses poisoned by the closely related species I. hendecaphylla and to 3‐NPA poisoning of other animals, including humans. 3‐NPA is thought to cause this neurological syndrome. To our knowledge, this is the first authenticated report of I. spicata poisoning in grazing animals. We also report here the first published evidence that 3‐NPA and indospicine exist in naturalised I. spicata in Australia and of the formation of indospicine residues in tissues of animals grazing paddocks infested with I. spicata.     

The development and integrity of equine pre‐antral follicles cultured in vitro with follicle‐stimulating hormone (FSH) supplementation

This study investigated the effects of different concentrations of FSH (10, 50, 100 and 200 ng/ml) in supplemented MEM+ on the development of equine pre‐antral follicles that were cultured in vitro for 2 or 6 days. The ovaries (n = 5) from mares in seasonal anoestrus were collected from a local abattoir. Ten ovarian tissue fragments of approximately 3 × 3 × 1 mm were obtained from each animal. The fragments were cultured in situ for 2 days (D2) or 6 days (D6) in MEM+ or MEM+ supplemented with FSH at four different concentrations, establishing the following 11 groups: control (D0); MEM + (D2); MEM + (D6); MEM + 10 ng/ml of FSH (D2); MEM + 10 ng/ml of FSH (D6); MEM + 50 ng/ml of FSH (D2); MEM + 50 ng/ml of FSH (D6); MEM + 100 ng/ml of FSH (D2); MEM + 100 ng/ml of FSH (D6); MEM + 200 ng/ml of FSH (D2); and MEM + 200 ng/ml of FSH (D6). Follicles were observed in only 9.65% (388 of 4,018) of the histological sections. Of the 861 follicles evaluated, 488 were in the primordial stage, and 373 were in various developmental stages; 59.7% were morphologically normal. Regarding the integrity of the pre‐antral follicles, the groups with 100 ng/ml FSH of 2‐days culture as well as 50, 100 and 200 ng/ml FSH of 6‐days culture provided the best results. In conclusion, the in vitro culture of abattoir‐derived equine ovarian fragments presented better morphological integrity when supplemented with FSH for 6 days, in comparison with the MEM culture group. However, no clear effects were observed with FSH regarding the promotion of activation from a primordial to a developing follicle.     

Bilateral iliac arterial thrombosis in an alpaca (Vicugna pacos) cria

A 3-month-old male alpaca was presented for acute onset of non-weight-bearing left hind limb lameness. Antemortem diagnostics revealed a mass to the right of the urinary bladder and no blood flow in the left femoral artery. Necropsy revealed bilateral iliac arterial thrombi and an abscess near the urinary bladder.