Evaluation of the risks of shedding Salmonellae and other potential pathogens by therapy dogs fed raw diets in Ontario and Alberta

Dogs that participate in animal-assisted interventions (AAIs), often called 'therapy dogs', commonly interact with humans whose immune systems are not functioning optimally. The advisability of feeding raw meat (including poultry) to these animals remains a highly contentious issue, in spite of increasing evidence that raw meat is frequently contaminated with Salmonella. We set out to determine if consuming raw meat influences the risk of therapy dogs shedding Salmonella and other pathogens. Two hundred healthy therapy dogs from Ontario and Alberta were enrolled. Between May 2005 and November 2006, fecal specimens were collected from each dog every 2 months for 1 year, along with a log of places visited, antimicrobial use within the home, dog health status and diet. Specimens were cultured for Salmonella, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum cephalosporinase (ESC) Escherichia coli and Clostridium difficile. Forty (20%) of the dogs were reported to have been fed raw meat at some point during the year. The incidence rate of Salmonella shedding in the raw meat-fed dogs was 0.61 cases/dog-year, compared with 0.08 cases/dog-year in dogs that were not fed raw meat (P < 0.001). Controlling for therapy dog group, the repeated measures, and pig ear consumption and diarrhoea in the 2 months prior to specimen submission, dogs that consumed raw meat were significantly more likely to test positive for Salmonellaat least once during the year than dogs that did not eat raw meat [odds ratio (OR) 22.7; 95% confidence interval (CI) 3.1-58.8; P < 0.001]. Specific Salmonella serovars were more common among dogs that consumed raw meat versus those that did not include S. Typhimurium, S. Heidelberg and S. Kentucky. Raw meat consumption was also significantly associated with shedding ESC E. coli (OR 17.2; 95% CI 9.4-32.3). No associations between C. difficile, MRSA or VRE and consumption of raw meat were detected. We recommend that dogs fed raw meat should be excluded from AAI programmes, particularly when the programmes involve interaction with humans at high risk of infection or adverse sequelae attributable to infection. Furthermore, although AAI dogs may not be representative of the general population of dogs, we also recommend that feeding of raw meat to dogs is to be avoided in homes where immunocompromised people live.     

Spread in South Africa of the Oriental latrine fly Chrysomya megacephala. (Fabricius) (Diptera: Calliphoridae), an introduced species closely resembling Chrysomya bezziana Villeneuve.

Chrysomya megacephala, also known as the Oriental latrine fly, is indigenous to south-east Asia. During the 1970's it successfully invaded Africa and South America, and more recently during the 1980's also established itself in the United States of America. Although the first specimens from South Africa were collected from the south-western Cape Province in 1978, no published data appears to exist on its subsequent spread or status in southern Africa. During May 1991 a specimen of C. megacephala was incidentally captured near Beaufort West, Cape Province, South Africa, which prompted re-examination of blow-flies captured in the Kruger National Park during 1984. In this way it was found that C. megacephala was already well established in the south-eastern Transvaal by mid-1984. Adult C. megacephala can easily be confused with C. bezziana and medical/veterinary entomologists and veterinarians should take note of the existence of this species and the fact that it is probably widespread throughout southern Africa at this state.     

Effects of transforming growth factor-α on parathyroid hormone- and parathyroid hormone-related protein- mediated bone resorption and adenylate cyclase stimulation in vitro

The effects of transforming growth factor-alpha (TGF alpha) were determined on the ability of parathyroid hormone (PTH) or parathyroid hormone-related protein (PTHrP) to stimulate bone resorption and adenylate cyclase in vitro. Bovine PTH-(1-34) and human PTHrP-(1-34) were equipotent in their ability to stimulate bone resorption in neonatal mouse calvaria with maximal stimulation (2.9 and 2.8-fold increases in 45Ca release, respectively) at a concentration of 10 nM. Combinations of TGF alpha with bPTH-(1-34) or hPTHrP-(1-34) had additive effects on their ability to stimulate bone resorption when submaximal concentrations of the agonists were used. There was no evidence of synergism between TGF alpha bPTH-(1-34) or hPTHrP-(1-34) in their ability to stimulate bone resorption in vitro, nor was TGF alpha able to increase bone resorption induced by maximal concentrations of bPTH-(1-34) or hPTHrP-(1-34). TGF alpha potentiated the effects of either bPTH-(1-34) or hPTHrP-(1-34) on the stimulation of adenylate cyclase in osteoblast-like ROS 17/2.8 cells. These data indicate that TGF alpha has additive effects with submaximal concentrations of PTH or PTHrP on their ability to stimulate bone resorption which may be important in the pathogenesis of humoral hypercalcemia of malignancy.     

Immune response in pigs to Aujeszky's disease viruses defective in glycoprotein g1 or gX.

Two Aujeszky's disease virus glycoprotein genes, gX and g1, have been used to produce deletion mutants which have then been developed into vaccines. These deletions then allow differentiation between pigs infected with wild type virus and those given the vaccine. It is not clear whether the glycoproteins encoded for by these genes are needed to induce a full protective immune response, in which case deletion mutants would suffer from lack of potency. To test this, commercially available Aujeszky's virus vaccines which lacked either gX or g1 were compared and isogenic constructs were made which differed only in the absence or presence of gX and, or, g1. These constructs and vaccines were used to vaccinate the natural host of Aujeszky's disease, the pig, and potency was measured using challenge with wild type virus. In all cases vaccines which lacked g1 performed significantly less well than those in which g1 was present, whereas deletions of gX had no significant effect on vaccine performance.     

Small intestinal starch digestion in steers: effect of various levels of abomasal glucose, corn starch and corn dextrin infusion on small intestinal disappearance and net glucose absorption

Eight Holstein steers (four at 300 kg, four at 406 kg) fitted with an elevated carotid artery, hepatic portal and mesenteric venous catheters, and abomasal and ileal cannulas were used in several 4 x 4 Latin square experiments to evaluate small intestinal starch digestion. They were fed alfalfa hay at 1.5% of BW and abomasally infused with water or glucose, corn starch or corn dextrin (one carbohydrate per Latin square) at 20, 40 or 60 g/h, with subsequent determination of small intestinal disappearance and net portal glucose absorption. Increasing the amount of all three carbohydrates infused abomasally increased the amount of carbohydrate disappearing in the small intestine. Increased infusion of glucose caused a continual increase (linear, P less than .01) in net glucose absorption, whereas net glucose absorption for starch and dextrin was maximal at the 20 g/h infusion (quadratic, P less than .05). With the 60 g/h infusion, 94% of the glucose but only 38% of starch and 29% of small intestinal dextrin disappearance could be accounted for as net glucose absorption, leaving a large portion of starch and dextrin disappearance unaccounted for. Of the infused starch and dextrin passing the ileum, 5.8 and 7.3%, respectively, was unpolymerized glucose, indicating that, at least in the distal small intestine, complete starch hydrolysis exceeded the capacity for glucose disappearance. It is concluded that only about 35% of the raw corn starch disappearing in the steer's small intestine resulted in net portal glucose absorption.     

Predicting behavioral changes associated with age-related cognitive impairment in dogs

OBJECTIVE: To monitor the progression of age-related behavioral changes in dogs during a period of 6 to 18 months and to determine whether signs of dysfunction in any of 4 behavioral categories can be used to predict further impairment. DESIGN: Age-stratified cohort study. ANIMALS: 63 spayed female and 47 castrated male dogs 11 to 14 years of age. PROCEDURE: Data were collected from randomly selected dog owners who were interviewed by telephone twice at a 12- to 18-month interval; data were included if the dog had lived > or = 6 months between interviews. The interview focused on signs of impairment in the following behavioral categories: orientation in the home and yard, social interactions with human family members, house training, and the sleep-wake cycle. Dogs were determined to have impairment in 0 behavioral categories (on the basis of < or = 1 sign for each category), impairment in 1 category (> or = 2 signs of dysfunction in that category), or impairment in > or = 2 categories. RESULTS: Between interviews, 22% (16/73) of dogs that did not have impairment in a category at the time of the first interview developed impairment in that category by the time of the second interview. Forty-eight percent (13/27) of dogs that had impairment in 1 category at the time of the first interview developed impairment in > or = 2 categories by the time of the second interview and were significantly more likely to develop impairment in > or = 2 categories, compared with dogs that initially had impairment in 0 categories. Dogs with 1 sign of dysfunction in orientation were significantly more likely to develop impairment in that category, compared with dogs that had 0 signs of dysfunction in orientation. CONCLUSIONS AND CLINICAL RELEVANCE: Age-related behavioral changes in dogs are progressive. Clinicians should consider trying to predict which dogs are most likely to become progressively impaired during the subsequent 6 to 18 months.     

Multiplex polymerase chain reaction for distinguishing Taylorella equigenitalis from Taylorella equigenitalis-like organisms.

It is difficult to distinguish isolates of Taylorella equigenitalis, the cause of contagious equine metritis, from a T. equigenitalis-like organism isolated from asymptomatic donkeys and horses. Although T. equigenitalis is responsible for a severe, contagious disease of the reproductive tract of equids, the T. equigenitalis-like organism, although contagious, does not appear to produce disease. Because of the economic consequences of correctly distinguishing isolates of these 2 microorganisms, a polymerase chain reaction (PCR)-based assay was developed that will distinguish isolates of T. equigenitalis from the T. equigenitalis-like microorganism. The primers used in the PCR assay were designed to amplify unique regions of the gene encoding the 16S ribosomal RNA.