A comparison of diagnostic techniques for postpartum endometritis in dairy cattle.

Holstein cows (n=221) from eight commercial dairy herds were examined for endometritis between 28 and 41 days postpartum using 5 diagnostic techniques: (1) vaginoscopy; (2) ultrasonographic assessment of uterine fluid volume; (3) ultrasonographic assessment of endometrial thickness; (4) endometrial cytology collected by cytobrush; and (5) endometrial cytology collected by uterine lavage. Concordance correlation was used to evaluate the reliability of cytobrush and lavage cytology. Cytobrush cytology was found to have the greatest intraobserver repeatability (cytobrush, rho(c)=0.

Associations between feed and water antimicrobial use in farrow-to-finish swine herds and antimicrobial resistance of fecal Escherichia coli from grow-finish pigs.

Escherichia coli (n = 1439), isolated from the feces of apparently healthy grow-finish pigs in 20 herds, were tested for susceptibility to 16 antimicrobials. Logistic regression models were developed for each resistance that was observed in more than 5% of the isolates. Each production phase's (suckling, nursery, grow-finish pigs or sows) antimicrobial exposure rate, through feed or water, was considered as a risk factor.

Complete rejection of a T-cell lymphoma due to synergism of T-cell receptor costimulatory molecules, CD80, CD40L, and CD40.

The equal importance of the qualitative and quantitative characteristics of antigen presentation as well as the set of costimulatory signals provided by antigen presenting cells to T-cells in determining the outcome of T-cell responses at the time of antigen recognition is now clear. Moreover, an important function in innate mechanisms has been recently attributed to costimulatory molecules demonstrating their relevant role in different stages of immune response. In this paper, we demonstrated the ability of CD40L (CD154) and CD80 costimulatory molecules expression in a T-cell lymphoma to induce both T-cell dependent and independent immune responses leading to an important anti-tumor effect.

A case-control study of factors associated with development of clinical disease due to West Nile virus, Saskatchewan 2003.

Reason For Performing Study: West Nile virus (WNV) was first diagnosed in Saskatchewan equids in 2002. AWNV epidemic was considered highly likely for 2003, which would provide a unique opportunity to study all aspects of WNV subclinical infection and clinical disease development in a relatively naive population.

Hypothesis: There are individual equid attributes and management risk factors associated with development of clinical disease.

Factors associated with West Nile virus disease fatalities in horses.

In 2003, the occurrence and location of horses with clinical signs of West Nile virus infection were identified in the southern portion of Saskatchewan with the help of veterinarians, owners, and the regional laboratory. A total of 133 clinical cases were reported between July 30 and September 19, 2003; however, postseason surveillance suggests that the number of cases was underestimated. The case fatality rate was 43.

Chlorate poisoning in beef cattle.

A disease syndrome characterized by hemolysis, methemoglobinemia, methemoglobinuria, and death was observed in a herd of purebred Limousin beef cattle grazing on pasture in November in Alberta. Improper disposal of the nonselective herbicide, sodium chlorate, was identified as the causal agent. Highly variable blood methemoglobin levels reflected differences in herbicide consumption.

Industrial sources influence air concentrations of hydrogen sulfide and sulfur dioxide in rural areas of western Canada.

A survey of monthly average concentrations of sulfur dioxide (SO2) and hydrogen sulfide (H2S) at rural locations in western Canada (provinces of Alberta, British Columbia, and Saskatchewan) was conducted in 2001-2002, as part of an epidemiological study of the effects of oil and gas industry emissions on the health of cattle. Repeated measurements were obtained at some months and locations. We aimed to develop statistical models of the effect of oil and gas infrastructure on air concentrations.

Seroprevalence and risk factors for infection with West Nile virus in Saskatchewan horses, 2003.

The primary objectives of this study were to determine the seroprevalence of West Nile virus (WNV) infection of horses in Saskatchewan in 2003 and to identify risk factors for the infection. Blood samples were collected in August and October from 212 horses in 20 herds in 5 geographic zones. After accounting for within-herd clustering, the proportion of horses that had been infected with WNV, as determined by IgG and IgM antibody response, was 55.

Mycoplasma hyopneumoniae bacterins and porcine circovirus type 2 (PCV2) infection: induction of postweaning multisystemic wasting syndrome (PMWS) in the gnotobiotic swine model of PCV2-associated disease.

Groups (5 to 15 per group) of gnotobiotic swine were infected oronasally with porcine circovirus type 2 (PCV2) at 3 days of age and then given 1 of 6 different commercial Mycoplasma hyopneumoniae (M. hyopneumoniae) bacterins as either a single dose (7 d of age, 1 application products) or 2 doses (7 and 21 d of age, 2 application product). Control groups received PCV2 alone (n = 9) or were infected with PCV2 and immunized twice with keyhole limpet hemocyanin (KLH) emulsified in incomplete Freund's adjuvant (ICFA) (n = 7).

Effects of exposure to naphthenic acids in tree swallows (Tachycineta bicolor) on the Athabasca oil sands, Alberta, Canada.

Naphthenic acids (NAs) are a group of carboxylic acids that are of particular concern to the steadily growing oil sands mining industry of Alberta, Canada, because they become highly concentrated in the water used for oil sands extraction and are toxic to aquatic biota and mammals. Upon mine closure, vast amounts of process-affected water will need to be reclaimed and proven safe for wildlife colonizing reclaimed areas. The effects of exposure to NAs have not been investigated in avian species.

Increased thyroid hormone levels in tree swallows (Tachycineta bicolor) on reclaimed wetlands of the athabasca oil sands.

The oil sands of Alberta, Canada are one of the world's largest reserves of crude oil. Oil sands mining companies are now investigating the ecological impacts of reclamation strategies in which wetlands are used for the bioremediation of waste materials. To examine the endocrine disrupting potential of chemicals in Oil Sands Process Materials (OSPM), thyroid hormone concentrations were measured in plasma and thyroid glands of nestling tree swallows (Tachycineta bicolor) from wetlands partly filled with mine tailings.

Tree swallows (Tachycineta bicolor) nesting on wetlands impacted by oil sands mining are highly parasitized by the bird blow fly Protocalliphora spp.

Oil sands mining is steadily expanding in Alberta, Canada. Major companies are planning reclamation strategies for mine tailings, in which wetlands will be used for the bioremediation of water and sediments contaminated with polycyclic aromatic hydrocarbons and naphthenic acids during the extraction process. A series of experimental wetlands were built on companies' leases to assess the feasibility of this approach, and tree swallows (Tachycineta bicolor) were designated as upper trophic biological sentinels.

Effect of experimental ectoparasite control on bartonella infections in wild Richardson's ground squirrels.

The purpose of this study was to investigate the role of ectoparasites in transmitting Bartonella infections in wild Richardson's ground squirrels (Spermophilus richardsonii). Richardson's ground squirrels were trapped, examined for fleas, and tested for Bartonella bacteremia once monthly, at six sites, from April to September 2004. After the initial trapping session in April, burrows at three sites were treated with deltamethrin insecticide.

Demographic features of Bartonella infections in Richardson's ground squirrels (Spermophilus richardsonii).

The epidemiology of Bartonella infections in Richardson's ground squirrels (Spermophilus richardsonii) was studied at multiple sites in Saskatchewan, Canada, from 2002 to 2004. The overall prevalence of Bartonella infection was 48%. Juvenile squirrels were significantly more likely to be infected with Bartonella than were adults (58% and 37%, respectively), and juvenile animals also were significantly more likely to have high levels of bacteremia compared to adult animals.

Marking transgenic Xenopus froglets with passive micro transponders.

Standard methods to mark Xenopus laevis individuals like tattooing or clipping toenails are inappropriate for the fast growing and regenerating small froglets and the previously used transponders are too large. In this study we successfully adapted micro transponders to tag these animals. Using these new transponders one can now tag small froglets directly after metamorphosis, which has not been possible previously.

Response of calves to challenge exposure with virulent bovine respiratory syncytial virus following intranasal administration of vaccines formulated for parenteral administration.

Objective: To determine whether single-fraction and combination modified-live bovine respiratory syncytial virus (BRSV) vaccines commercially licensed for parenteral administration could stimulate protective immunity in calves after intranasal administration.

Design: Randomized controlled trial.

Animals: 39 calves.

Age-dependent seroprevalence of antibodies against a Helicobacter pylori-like organism and Helicobacter pylori in commercially reared swine.

Objective: To determine the prevalence of antibodies against a swine-origin Helicobacter pylori-like organism (HPLO) and H pylori in conventionally reared swine.

Animals: 640 conventionally reared swine of various ages from 16 high-health farms in Canada, 20 sows from Ohio, and 35 gnotobiotic swine.

Procedures: Blood was collected from the cranial vena cava.

Mucosal inoculation with an attenuated mouse pneumovirus strain protects against virulent challenge in wild type and interferon-gamma receptor deficient mice.

Protective mechanisms underlying the responses to mucosal vaccination are not yet clearly defined. Using the natural mouse pneumovirus pathogen, pneumonia virus of mice (PVM), we explore responses of wild type and interferon-gamma (IFNgamma) receptor gene-deleted mice to virulent challenge after mucosal vaccination with an attenuated virus strain. Serum neutralizing antibodies develop after intranasal inoculation with 30 pfu of attenuated, replication-competent PVM strain 15, which correlate with diminished gross and microscopic pulmonary pathology and protection from weight loss in response to subsequent challenge with the virulent parent PVM strain J3666.

Porcupine quill injuries in dogs: a retrospective of 296 cases (1998-2002).

The purpose of this retrospective study was to identify factors associated with quill injury in dogs. A second objective was to determine the risk of complications and any factors that would predict the likelihood of complications. Hospital records of 296 porcupine quill injuries in dogs from 1998 to 2002 were studied.

Prediction of human cases of West Nile virus by equine cases, Saskatchewan, Canada, 2003.

In 2003, an outbreak of West Nile virus (WNV) occurred in Saskatchewan, Canada from July to September. One-hundred thirty-three horse cases and 947 human cases were recorded and data were analyzed retrospectively for evidence of clustering to determine if clinical infection in the horse population could be used to estimate human risk of infection with WNV. Kulldorff's scan statistic was used to identify spatial-temporal clusters in both the human and horse cases.

Transgenic Xenopus laevis strain expressing cre recombinase in muscle cells.

For reproducible analyses of gene function in Xenopus, the use of transgenic strains is a promising approach but has limitations when investigating factors interfering with development. Therefore, inducible systems are attractive alternatives, and a binary system based on recombinases is a most versatile approach. We have shown previously that Cre and FLP recombinases are active in Xenopus laevis and can induce a silent reporter gene in a corresponding reporter strain.

Analysis of a practice management computer software program for owner compliance with recall reminders.

The purpose of this study was to describe clients' level of compliance with reminders that are computer generated and to identify factors associated with owner response to a recall. Client response to a recall notice revealed that clients responded to reminders for vaccination about 3 times less often than for the other recall codes combined (dental procedures, laboratory tests, medical progress examinations, and neutering). These results suggest that veterinarians need to move away from annual vaccination reminders and toward the promotion of preventive veterinary services, such as annual wellness examinations, screening laboratory testing, and routine dental procedures.

Disease outbreak investigation in food animal practice.

In addition to excellent observation skills and a good understanding of production medicine, veterinarians require the tools of epidemiology for the successful investigation of disease outbreaks. Food supply veterinary practitioners are often called upon to investigate various types of disease outbreaks. In this article, the authors outline the primary questions a practitioner should address and summarize a systematic approach to determining the causes of an outbreak and minimizing further losses.

An examination of the prevalence of and risk factors for shedding of Cryptosporidium spp. and Giardia spp. in cows and calves from western Canadian cow-calf herds.

The primary objectives of this study were to describe the prevalence and risk factors for Cryptosporidium spp. and Giardia spp. infection in cows and calves during the calving season in western Canadian cow-calf herds.

Effects of oil sands tailings compounds and harsh weather on mortality rates, growth and detoxification efforts in nestling tree swallows (Tachycineta bicolor).

Oil sands mining companies in Alberta, Canada, are evaluating the feasibility of using wetlands to detoxify oil sands process material (OSPM) as a reclamation strategy. Reproductive success, nestling growth, survival and ethoxyresorufin-o-deethylase (EROD) activity were measured in tree swallows (Tachycineta bicolor) on experimental wetlands. In 2003, harsh weather triggered a widespread nestling die-off.