Prevalence and risk-factor analysis of Shiga toxigenic Escherichia coli in faecal samples of organically and conventionally farmed dairy cattle

Cattle are a natural reservoir for Shiga toxigenic Escherichia coli (STEC), however, no data are available on the prevalence and their possible association with organic or conventional farming practices. We have therefore studied the prevalence of STEC and specifically O157:H7 in Swiss dairy cattle by collecting faeces from approximately 500 cows from 60 farms with organic production (OP) and 60 farms with integrated (conventional) production (IP). IP farms were matched to OP farms and were comparable in terms of community, agricultural zone, and number of cows per farm. E. coli were grown overnight in an enrichment medium, followed by DNA isolation and PCR analysis using specific TaqMan assays. STEC were detected in all farms and O157:H7 were present in 25% of OP farms and 17% of IP farms. STEC were detected in 58% and O157:H7 were evidenced in 4.6% of individual faeces. Multivariate statistical analyses of over 250 parameters revealed several risk-factors for the presence of STEC and O157:H7. Risk-factors were mainly related to the potential of cross-contamination of feeds and cross-infection of cows, and age of the animals. In general, no significant differences between the two farm types concerning prevalence or risk for carrying STEC or O157:H7 were observed. Because the incidence of human disease caused by STEC in Switzerland is low, the risk that people to get infected appears to be small despite a relatively high prevalence in cattle. Nevertheless, control and prevention practices are indicated to avoid contamination of animal products.     

Investigation of a possible chain of Streptococcus suis infection in a pig breeding community using PCR-based genotyping

Streptococcus (S.) suis plays an important role in pig breeding causing invasive diseases such as meningitis and polyarthritis. Herd problems with Streptococcus suis are common in many pig farms and are frequently characterised by disease outbreaks. In this context, it is often important to identify chains of infection, e.g. between a farrow-to-wean and a grower farm. In the following case report a possible chain of infection among the different farms of a farrow-to-finish system was investigated. In two grower units herd problems with S. suis were present; the mortality was higher than 5 %. It appeared likely, that the streptococci causing these problems were transmitted from a single farrow-to-wean unit to the two different grower farms. In the respective farms swabs were taken from different healthy animals and, in the case of the grower farms, also from the infected animals. Genotypic profiling of strains by a multiplex-PCR and AFLP typing method revealed that two different S. suis pathotypes were responsible for the herd problems. Both pathotypes could not be detected in the farrow-to-wean farm.Thus, a chain of infection originating from the farrow-to-wean farm appeared unlikely. The multiplex PCR was in this case sufficient to elucidate the described problem.     

Breed associations for canine exocrine pancreatic insufficiency

BACKGROUND: Knowledge of breed associations is valuable to clinicians and researchers investigating diseases with a genetic basis. HYPOTHESIS: Among symptomatic dogs tested for exocrine pancreatic insufficiency (EPI) by canine trypsin-like immunoreactivity (cTLI) assay, EPI is common in certain breeds and rare in others. Some breeds may be overrepresented or underrepresented in the population of dogs with EPI. Pathogenesis of EPI may be different among breeds. ANIMALS: Client-owned dogs with clinical signs, tested for EPI by radioimmunoassay of serum cTLI, were used. METHODS: In this retrospective study, results of 13,069 cTLI assays were reviewed. RESULTS: An association with EPI was found in Chows, Cavalier King Charles Spaniels (CKCS), Rough-Coated Collies (RCC), and German Shepherd Dogs (GSD) (all P < .001). Chows (median, 16 months) were younger at diagnosis than CKCS (median, 72 months, P < .001), but not significantly different from GSD (median, 36 months, P = .10) or RCC (median, 36 months, P = .16). GSD (P < .001) and RCC (P = .015) were younger at diagnosis than CKCS. Boxers (P < .001), Golden Retrievers (P < .001), Labrador Retrievers (P < .001), Rottweilers (P = .022), and Weimaraners (P = .002) were underrepresented in the population with EPI. CONCLUSIONS AND CLINICAL IMPLICATIONS: An association with EPI in Chows has not previously been reported. In breeds with early-onset EPI, immune-mediated mechanisms are possible or the disease may be congenital. When EPI manifests later, as in CKCS, pathogenesis is likely different (eg, secondary to chronic pancreatitis). Underrepresentation of certain breeds among dogs with EPI has not previously been recognized and may imply the existence of breed-specific mechanisms that protect pancreatic tissue from injury.     

Veterinary Work in the Field with Fish and Other Aquatic Species

Veterinarians who work with fish and other aquatic species often must perform examinations, diagnostic investigations, and treatments away from the clinic or laboratory. Careful planning is important, and attention to biosecurity is essential. Various items of equipment form part of the field kit for such work and range from measuring scales to surgical instruments and anesthetic agents. Excellent recordkeeping at the site is essential.     

MAF takes over TB scheme — A reply

Madam:— I refer to the letter by Joe Tyndel “MAF takes over Tb scheme” (N.Z. vet. J. 34: 138). While not disagreeing with the sentiment of Dr Tyndel's letter which is a welcome first public correspondence about MAF moves towards commercialisation, I do wish to correct a major inaccuracy contained in the letter.     

Oropharyngeal dysphagias in the dog: A cinefluorographic analysis of experimentally induced and spontaneously occurring swallowing disorders

Cinefluorography and videofluorography were used to record and analyze functional swallowing deficits of 12 dogs with spontaneously occurring oropharyngeal dysphagias and six experimental dogs with selected neurectomies. Ten of the 12 dogs had dysphagias affecting the cricopharyngeal stage of the oropharyngeal phase of swallowing. Two dogs had mixed oropharyngeal dysphagias. Clinical signs of cricopharyngeal dysphagia could not be differentiated from those of dysphagias due to pharyngeal or mixed oropharyngeal deficits. Signs of cricopharyngeal dysphagia consisted of: 1) repeated attempts to swallow; 2) excessive head movement; 3) dropping food from the mouth after unsuccessful swallowing attempts; 4) reingestion of dropped food. Nine of these dogs had cinefluorographic evidence of asynchrony between the normal pharyngeal contraction and relaxation, and subsequent cricopharyngeal relaxation and contraction. Only one dog demonstrated a consistent cricopharyngeal non-opening (achalasia). Seven of the dogs responded dramatically to cricopharyngeal myotomy. Two dogs with mixed oropharyngeal dysphagias had poor contractility of the pharyngeal muscles in addition to cricopharyngeal dysphagia. Clinical and cinefluorographic evaluation following cricopharyngeal myotomy of one dog verified exacerbation of functional deficits due to the iatrogenic cricopharyngeal chalasia. Esophagopharyngeal reflux accentuated the contrast medium retention in the pharynx and laryngotracheal aspiration. The need was stressed for careful differentiation between cricopharyngeal dysphagia and dysphagias involving the pharyngeal stage. Four experimental dogs with selective bilateral neurectomies of branches of the glossopharyngeal (IX) and vagus (X) nerves were evaluated clinically and cinefluorographically in an attempt to identify the pathogenesis of cricopharyngeal dysphagia. The variable results in the four dogs and the observed recovery in two dogs suggested that peripheral motor nerve deficits are not a major cause of cricopharyngeal dysphagia. Glossopharyngeal neurectomy in two dogs induced a profound functional disorder involving the pharyngeal and cricopharyngeal stages and the esophageal phase of swallowing. This would support a new hypothesis that the glossopharyngeal nerve is sensory to the esophagus as well as the pharynx, and may play a major role in disorders of the pharynx, upper esophageal sphincter, and esophagus, including congenital or acquired megaesophagus.