Animals In Canada Research Articles

Mycobacterial infections in horses

Mycobacterial infections in horses

Parasite prevalence in fecal samples from shelter dogs and cats across the Canadian provinces.

BackgroundIn Canada, surveys of enteric parasites in dogs and cats have been reported sporadically over the past 40 years, mostly focusing on a specific region. The present work was performed to determine the current prevalence of various parasites in fecal samples from shelter dogs and cats across the Canadian provinces.MethodsA total of 1086 dog and 636 cat fecal samples from 26 shelters were analysed using a sugar solution double centrifugal flotation technique. Prevalences (national, regional, provincial, age and parasite-specific), were calculated and compared using the Fisher-Exact test. A multiplex PCR was performed to distinguish Taenia spp, Echinococcus granulosus and E. multilocularis on samples positive for taeniid eggs.ResultsOverall, 33.9% of dogs and 31.8% of cats were positive for at least one parasite. Toxocara canis and T. cati were the most prevalent parasite present in fecal samples followed by Cystoisospora spp. Prevalence in dogs was similar across the Atlantic, East, West and Pacific regions, while prevalence in cats varied regionally. Eggs of E. granulosus/E. canadensis were detected in samples from dogs from BC, AB, and ON.ConclusionsData from this study will help in the development of strategies, based on the level of risk per geographic location for the prevention and response to these parasites in pets and free-roaming and shelter animals in Canada.

Using informatics and the electronic medical record to describe antimicrobial use in the clinical management of diarrhea cases at 12 companion animal practices.

Antimicrobial drugs may be used to treat diarrheal illness in companion animals. It is important to monitor antimicrobial use to better understand trends and patterns in antimicrobial resistance. There is no monitoring of antimicrobial use in companion animals in Canada. To explore how the use of electronic medical records could contribute to the ongoing, systematic collection of antimicrobial use data in companion animals, anonymized electronic medical records were extracted from 12 participating companion animal practices and warehoused at the University of Calgary. We used the pre-diagnostic, clinical features of diarrhea as the case definition in this study. Using text-mining technologies, cases of diarrhea were described by each of the following variables: diagnostic laboratory tests performed, the etiological diagnosis and antimicrobial therapies. The ability of the text miner to accurately describe the cases for each of the variables was evaluated. It could not reliably classify cases in terms of diagnostic tests or etiological diagnosis; a manual review of a random sample of 500 diarrhea cases determined that 88/500 (17.6%) of the target cases underwent diagnostic testing of which 36/88 (40.9%) had an etiological diagnosis. Text mining, compared to a human reviewer, could accurately identify cases that had been treated with antimicrobials with high sensitivity (92%, 95% confidence interval, 88.1%–95.4%) and specificity (85%, 95% confidence interval, 80.2%–89.1%). Overall, 7400/15,928 (46.5%) of pets presenting with diarrhea were treated with antimicrobials. Some temporal trends and patterns of the antimicrobial use are described. The results from this study suggest that informatics and the electronic medical records could be useful for monitoring trends in antimicrobial use.

The application of medical informatics to the veterinary management programs at companion animal practices in Alberta, Canada: A case study

Companion animals closely share their domestic environment with people and have the potential to, act as sources of zoonotic diseases. They also have the potential to be sentinels of infectious and noninfectious, diseases. With the exception of rabies, there has been minimal ongoing surveillance of, companion animals in Canada. We developed customized data extraction software, the University of, Calgary Data Extraction Program (UCDEP), to automatically extract and warehouse the electronic, medical records (EMR) from participating private veterinary practices to make them available for, disease surveillance and knowledge creation for evidence-based practice. It was not possible to build, generic data extraction software; the UCDEP required customization to meet the specific software, capabilities of the veterinary practices. The UCDEP, tailored to the participating veterinary practices’, management software, was capable of extracting data from the EMR with greater than 99%, completeness and accuracy. The experiences of the people developing and using the UCDEP and the, quality of the extracted data were evaluated. The electronic medical record data stored in the data, warehouse may be a valuable resource for surveillance and evidence-based medical research.

Transmission of Hypervirulence Traits via Sexual Reproduction within and between Lineages of the Human Fungal Pathogen Cryptococcus gattii

Since 1999 a lineage of the pathogen Cryptococcus gattii has been infecting humans and other animals in Canada and the Pacific Northwest of the USA. It is now the largest outbreak of a life-threatening fungal infection in a healthy population in recorded history. The high virulence of outbreak strains is closely linked to the ability of the pathogen to undergo rapid mitochondrial tubularisation and proliferation following engulfment by host phagocytes. Most outbreaks spread by geographic expansion across suitable niches, but it is known that genetic re-assortment and hybridisation can also lead to rapid range and host expansion. In the context of C. gattii, however, the likelihood of virulence traits associated with the outbreak lineages spreading to other lineages via genetic exchange is currently unknown. Here we address this question by conducting outgroup crosses between distantly related C. gattii lineages (VGII and VGIII) and ingroup crosses between isolates from the same molecular type (VGII). Systematic phenotypic characterisation shows that virulence traits are transmitted to outgroups infrequently, but readily inherited during ingroup crosses. In addition, we observed higher levels of biparental (as opposed to uniparental) mitochondrial inheritance during VGII ingroup sexual mating in this species and provide evidence for mitochondrial recombination following mating. Taken together, our data suggest that hypervirulence can spread among the C. gattii lineages VGII and VGIII, potentially creating novel hypervirulent genotypes, and that current models of uniparental mitochondrial inheritance in the Cryptococcus genus may not be universal.

Multi-Criteria Decision Analysis Tools for Prioritising Emerging or Re-Emerging Infectious Diseases Associated with Climate Change in Canada

Global climate change is known to result in the emergence or re-emergence of some infectious diseases. Reliable methods to identify the infectious diseases of humans and animals and that are most likely to be influenced by climate are therefore required. Since different priorities will affect the decision to address a particular pathogen threat, decision makers need a standardised method of prioritisation. Ranking methods and Multi-Criteria Decision approaches provide such a standardised method and were employed here to design two different pathogen prioritisation tools. The opinion of 64 experts was elicited to assess the importance of 40 criteria that could be used to prioritise emerging infectious diseases of humans and animals in Canada. A weight was calculated for each criterion according to the expert opinion. Attributes were defined for each criterion as a transparent and repeatable method of measurement. Two different Multi-Criteria Decision Analysis tools were tested, both of which used an additive aggregation approach. These were an Excel spreadsheet tool and a tool developed in software ‘M-MACBETH’. The tools were trialed on nine ‘test’ pathogens. Two different methods of criteria weighting were compared, one using fixed weighting values, the other using probability distributions to account for uncertainty and variation in expert opinion. The ranking of the nine pathogens varied according to the weighting method that was used. In both tools, using both weighting methods, the diseases that tended to rank the highest were West Nile virus, Giardiasis and Chagas, while Coccidioidomycosis tended to rank the lowest. Both tools are a simple and user friendly approach to prioritising pathogens according to climate change by including explicit scoring of 40 criteria and incorporating weighting methods based on expert opinion. They provide a dynamic interactive method that can help to identify pathogens for which a full risk assessment should be pursued.

Demonstration Wildlife: Negotiating the Animal Landscape of Vancouver's Stanley Park, 1888-1996

Abstract Since 1931, Canada has been a majority urban society with most of its population concentrated in a handful of southern cities. Given the urban character of Canadian society in the twentieth century, histories of large city parks, such as Stanley Park in Vancouver, BC, illustrate the changing relationship between people and wild animals in Canada because they represent local, regular encounters with a diverse range of animal species. The histories of local and regional parks in Canada reveal that human relations with wildlife were not limited to occasional, and sometimes fleeting, encounters in large national parks, distant from major population centres. As this article argues, the everyday interactions between people and animals within shared urban environments also influenced Canadian perceptions of wildlife and the management of park animals in the nineteenth and twentieth centuries. Park animal management policies and attitudes toward the place of animals in parks were not always informed by imagined, idealised concepts about wildlife from a distance but were shaped and changed over time according to local concerns and regular interactions between people and animals living in a shared environment.Over the course of the late nineteenth and twentieth centuries, humanâ€"animal relations on the Stanley Park peninsula shifted according to prevailing notions of ‘improvement’ and landscape modification current in the North American parks and later environmental movements. Prior to 1945, Park Board animal management policies embodied the perception that human modification of the animal composition of the park was a necessary improvement for the pleasure of tourists and other park visitors. After 1945, the Park Board moved away from such interventionist policies and began instead to foster habitat to establish sanctuaries for wildlife observation.

Characterization of bla CMY-2 Plasmids in Salmonella and Escherichia coli Isolates from Food Animals in Canada

One hundred thirty-four bla(CMY-2) plasmids from Salmonella and Escherichia coli strains from animals and food in Canada were characterized. Five plasmid groups were identified based on replicon type and restriction profiles. Three groups contained E. coli plasmids only. IncA/C plasmids included most multiresistant plasmids and all those of bovine origin.

Susceptibility of meat starter cultures to antimicrobials used in food animals in Canada.

Lactic acid bacteria (LAB) are extensively used in the food industry for fermentation processes. However, it is possible that these bacteria may serve as a reservoir for antibiotic resistance genes that can be transferred to pathogens, giving rise to public health concerns. Animal operations that use antimicrobials as growth promotants have been linked to the origin of resistance due to the selective effect of low levels of antimicrobial used in this management strategy. The objective of this study was to determine the antimicrobial susceptibilities and mechanisms of resistance for 30 isolates of meat starter cultures commonly used in dry sausage fermentations to 20 antimicrobial agents. Susceptibility tests were performed by broth microdilution using Iso-Sensitest broth (90%, vol/vol) and de Man Rogosa Sharpe (MRS) broth (10%, vol/vol). The results showed that all 30 isolates exhibited resistance to at least three antimicrobials regardless of antimicrobial class while 17 or 30% of strains were resistant to antibiotics in three or six different classes, respectively. The incidence of antimicrobial resistance was higher among Pediococcus pentosaceus and lower for Staphylococcus carnosus strains. Genetic determinants for the lincosamide, macrolide, and tetracycline antimicrobials were not found using PCR. Phenotypic resistance in the absence of known resistance genes found here suggests that other mechanisms or genes might have contributed to the negative results. Further studies are needed to explore the genetic mechanisms underlying the prevalence of antibiotic resistance in Pediococcus species.

Quantitation and Validation of Fluoroquinolones in Eggs Using Liquid Chromatography/Tandem Mass Spectrometry

Fluoroquinolone antibiotics are labeled for very limited veterinary use for treatment of some animals and pets, but they are not authorized for food animals in Canada, including egg-producing birds. Because they are approved for other animals, however, fluoroquinolones may appear in eggs through off-labeling or accidental use. This method is capable of quantitating and confirming the presence of 4 fluoroquinolones, ciprofloxacin, danofloxacin, enrofloxacin, and sarafloxacin, over the concentration range 1 to 60 microg/kg (ppb) using 2 internal standards, norfloxacin or lomefloxacin. The compounds are extracted with acidic acetonitrile, isolated using Oasis HLB solid-phase extraction, and quantitated by liquid chromatography/tandem mass spectrometry at 2 transitions. The limits of detection (microg/kg) were evaluated from between-day experiments as: ciprofloxacin, 0.22; danofloxacin (m/z 314), 0.32; enrofloxacin, 0.22; and sarafloxacin, 0.31. The values for the decision limit, CCalpha were 0.33, 0.36, 0.30, and 0.45 microg/kg, respectively.

Current status of regulating biotechnology-derived animals in Canada—animal health and food safety considerations

Development of an effective regulatory system for genetically engineered animals and their products has been the subject of increasing discussion among researchers, industry and policy developers, as well as the public. Since transgenesis and cloning are relatively new scientific techniques, transgenic animals are ‘novel’ organisms for which there is limited information. The issues associated with the regulation of transgenic animals pertain to environmental impact, human food safety, animal health and welfare, trade and ethics. It is a challenge for the developers to prove the safety of the products of biotechnology-derived animals and also for regulators to regulate this increasingly powerful technology with limited background information. In principle, an effective regulatory sieve should permit safe products while forming a formidable barrier for those posing an unacceptable risk. Regulatory initiatives for biotechnology-derived animals and their products should be able to ensure high standards for human and animal health, a sound scientific basis for evaluation; transparency and public involvement, and maintenance of genetic diversity. This review proposes a regulatory regime that is based on scientific risk based assessment and approval of products or by-products of biotechnology-derived animals and its application in context to Canadian regulations.

Guidelines development and scientific uncertainty: use of previous case studies to promote efficient production of guidelines on the care and use of fish in research, teaching and testing

AbstractThe Canadian Council on Animal Care (CCAC) develops guidelines on issues of current and emerging concern in response to the needs of the scientific community, advances in animal care, and the needs of the CCAC Assessment Program. Guidelines are developed by subcommittees of experts, and are based on sound scientific evidence. However, the process of guidelines' development can involve consideration of areas where there is little scientific certainty or where scientific evidence needs to be tempered by other ethical considerations. Often these are areas where recommendations to the community are most needed, to provide assistance to both investigators and animal care committees on how best to balance the well-being of experimental animals and the goals of scientific research. The process for drafting the CCAC guidelines on: the care and use of fish in research, teaching and testing (in preparation) will be used as an example of the development of guidelines in the face of uncertain science, alongside a discussion of the CCAC guidelines on: transgenic animals (1997), as an example of the employment of a precautionary approach. Fish are now one of the most commonly used laboratory animals in Canada. However, what constitutes well-being for fish is an emerging field with often conflicting scientific data, and this presents unique challenges in guidelines' development.

Phage-Based Typing Scheme for Salmonella enterica Serovar Heidelberg, a Causative Agent of Food Poisonings in Canada

Salmonella enterica serovar Heidelberg is perhaps the second most frequent Salmonella serovar isolated from humans and the most common isolated from animals in Canada. This pathogen has shown increasing resistance to antimicrobial agents and mimics the multidrug resistance observed in S. enterica serovar Typhimurium strain DT 104. However, unlike for serovar Typhimurium, a rapid and inexpensive subtyping method has not been available for large-scale surveillance efforts. We developed a phage typing scheme and subtyped 2,523 strains of serovar Heidelberg from outbreaks, sporadic infections, and environmental sources in Canada between January 1991 and December 2000. All strains were sensitive to one or more phages and could be subdivided into 49 phage types. A total of 196 isolates from 13 major outbreaks could be subtyped into six phage types, while 86 strains from family outbreaks were assigned to seven phage types. All strains were typeable, and epidemiologically related strains isolated from patients and implicated foods had identical phage types, antibiograms, and pulsed-field gel electrophoresis (PFGE) patterns. Combining PFGE with phage typing increased the discriminatory power of the analysis beyond that of either method alone. We concluded that this phage typing scheme, in conjunction with PFGE, enhances subtyping of serovar Heidelberg strains. Furthermore, this phage typing scheme is a rapid, economical, stable, and reliable epidemiologic tool for tracing the origin of food-borne disease and for the surveillance of sporadic infections.

Phenotypic and genotypic characterization of food animal isolates of Salmonella with reduced sensitivity to ciprofloxacin.

Reports of nontyphoidal Salmonella enterica subsp. enterica showing reduced sensitivity to ciprofloxacin (RSC) have increased rapidly during the past decade. Infection in humans with Salmonella possessing RSC may compromise the effectiveness of ciprofloxacin therapy. Nineteen among 4,357 Salmonella strains isolated from food animals in Canada from 1998 to 1999 showed RSC; 17 were from turkeys and 2 from chickens. All were resistant to nalidixic acid and sulfisoxazole and possessed RSC at a level of 0.125-0.5 microg/ml. PCR-RFLP of the gyrA quinolone resistance-determining region (QRDR) with Hinfl revealed that S. Bredeney and S. Heidelberg isolates possessed a mutation in this region. Single-strand conformational polymorphism (SSCP) analysis showed that S. Schwarzengrund and S. Senftenberg isolates also possessed a point mutation in the QRDR. DNA sequencing confirmed the findings and showed that all isolates possessed a base substitution in the gyrA QRDR. Sequencing revealed no mutations in the gyrB and silent wobble mutations in the parC QRDR. Reserpine, a known efflux pump inhibitor, did not effect the MICs for ciprofloxacin, nalidixic acid, and tetracycline. The mar operon could be induced in all isolates at 37 degrees C and in 18 of 19 at 30 degrees C; induction resulted in a two- to four-fold increase in the MIC of ciprofloxacin. In 14 of the 19 isolates, the mutation rate was two-fold or higher than in a ciprofloxacin sensitive S. Bredeney and S. Typhimurium LT2 control strain. Examination of clonal relatedness using pulsed-field gel electrophoresis (PFGE) and plasmid profiles indicated that some degree of clonal dispersion may have occurred, but the majority of isolates may have arisen from de novo mutations.

Diversity in Antimicrobial Resistance and Other Characteristics AmongSalmonellaTyphimurium DT104 Isolates

Multiresistant Salmonella enterica subspecies enterica serovar Typhimurium definitive type 104 (S. Typhimurium DT104 or DT104) bacteria are important pathogens in animals and humans. DT104 isolates are often called pentaresistant strains that spread clonally. The purpose of this study was to determine phenotypic, genotypic, and epidemiologic characteristics of 175 S. Typhimurium DT104 strains isolated from food-producing animals in Canada. More than 90% of the isolates were resistant to ampicillin (Amp), chloramphenicol (Chl), florfenicol (Flo), sulfisoxazole (Sul), and tetracycline (Tet), 53% of the isolates were additionally resistant to spectinomycin (Spc) and streptomycin (Str), and 28% to kanamycin (Kan) and neomycin (Neo). Sixty-one percent of the strains harbored a single 60-MDa plasmid, 21% contained 60- and 2.0-MDa plasmids, and 4% had 60, 4.6- and 2.0-MDa plasmids. Resistance to Kan and Neo was encoded by the aminoglycoside aphA-1 gene on 2.0-MDa plasmids, whereas resistance to trimethoprim (Tmp) and Sul was encoded by the dhfrIb gene on 4.6-MDa plasmids. Polymerase chain reactions (PCR) showed the presence of integrons with the ant (3")-Ia aminoglycoside adenyltransferase and the bla(PSE-1) beta-lactamase gene cassettes, and the presence of the flost gene in all but one strain resistant to Spc and Str, Amp, and Chl and Flo, respectively. DT104 isolates from cattle at six feedlots represented a separate clone; they were sensitive to Str and Spc and lacked the ant (3")-Ia gene. Pulsed-field gel electrophoresis (PFGE) using Bln I, Spe I, and Xba I resulted in 15, 12, and 8 PFGE patterns, respectively. In summary, we observed considerable diversity in phenotypic, genotypic, and epidemiological characteristics among the DT104 isolates.

Mad deer in Canadian wild?

Government officials have stepped up measures to prevent the spread of chronic wasting disease, or CWD, the deer form of BSE, in the Saskatchewan wilderness. Earlier this spring, a mule deer turned in by a hunter for what is now routine testing was found to have the disease. Although incidences of CWD have occurred in farmed elk in Saskatchewan, this was the first case of the disease to be found in a wild animal in Canada. Protective measures have included allowing more hunting in the area where the affected deer was found and outlawing the feeding of deer to reduce unnatural congregation of the animals. Although there is no proven link between CWD and disease in humans, officials have cautioned against eating venison from infected deer. AVhttp://saskatoon.about.com/aboutcanada/saskatoon/library/weekly/aa040901a.htm

Note on a second occurrence of thalattosaur remains (Reptilia: Neodiapsida) in British Columbia

A fragmentary thalattosaur specimen from the Late Triassic Pardonet Formation of northeastern British Columbia is the second reported occurrence of such animals in Canada. The group was previously known with certainty only from the Hosselkus Limestone of California, the Monte San Giorgio region shales of Italy and Switzerland, the Natchez Pass Formation of Nevada, and most recently, the Sulphur Mountain Formation of British Columbia. As such, the described material, which is indeterminate to genus, represents a slight geographic range extension of the Thalattosauria. The Norian age of this material represents a significant temporal range extension for the Thalattosauria, and it is the geologically youngest material known of this taxon.

Mycotoxicoses of domestic animals and their diagnosis

Mycotoxins have been named "agents in search of a disease," and the considerable progress in analytical methodology over the last 10 years has not changed this very much. The following are factors that contribute to the difficulty of making a diagnosis: (1) nonspecificity of lesions; (2) masking of mycotoxic effects by secondary effects, e.g., through immunosuppression; (3) late appearance of a lesion, e.g., bone marrow damage or neoplasia; (4) interaction of several mycotoxins or presence of other toxicants or deficiency states; (5) species variation in the response to the mycotoxin(s); (6) difficulty of linking a late appearing effect with a demonstrable cause; (7) low doses of mycotoxins may cause stimulating effects; and (8) not being aware of the potential of a mycotoxin as a causative factor in disease. The mycotoxins of major importance in Canada are trichothecenes, ochratoxin, zearalenone, and ergot. It is concluded that the significance of mycotoxins for animals in Canada is likely generally underestimated.

Powassan viral encephalitis: a review and experimental studies in the horse and rabbit.

Powassan virus strain M794, a member of the Flavivirus genus known to infect man and animals in Canada, was inoculated intracerebrally into rabbits and horses. No clinical signs were observed in rabbits, but widespread encephalitis resulted, characterized by lymphoid perivascular cuffing, lymphocytic meningitis, and lymphocytic choroiditis. In horses, eight days after inoculation, prominent neurological signs occurred and lesions were those of non-suppurative encephalomyelitis, neuronal necrosis, and focal parenchymal necrosis. The virus could not be reisolated from the rabbit or horse brains. Pathologic features, useful in separating some of the common North American equine neurological diseases, are discussed.

Fur trade in Canada: an econometric analysis

Much attention has been given during the 20th century to the 10-year cycle in the population of forest fur-bearing animals in Canada and its effect upon the fur trade and wild life generally. This paper investigates the relationship between the quantity of furs sold at the annual London auctions and the prices achieved at the auctions. Using bivariate time-series techniques equations relating price and supply are estimated and are then employed to answer the following questions: 1. (1) Are there cycles in prices due to fashion, business conditions or any other factors, which might have caused the cycles in quantities? 2. (2) Are supplies sold in one period influenced by prices obtained in previous periods? It is found that for most animals, and in particular for lynx and muskarts, there is no statistical evidence that the cycles in supply have been induced by cycles in prices.