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We conducted a prospective observational study on clinical and subclinical mastitis in 30 commercial meat-producing sheep flocks from 2 regions of the province of Quebec, Canada. A total of 2,792 ewes selected in late gestation were followed from lambing to weaning of lambs. The incidence of clinical mastitis for the total lactation period (average of 58 days) ranged among flocks from 0 to 6.6%, with a median of 1.2%. The most frequently isolated bacteria from the cases of clinical mastitis, in pure or mixed culture, were Mannheimia haemolytica (26%), Staphylococcus aureus (23%), and coagulase-negative staphylococci (17%). Incidence of clinical mastitis was higher in ewes that gave birth to 3 or more lambs and from the Estrie region, and was associated with an increase in ewe mortality, an increase in lamb mortality at the litter level, and a decrease in lamb's weaning weight for lambs born in multiple litter size or from ewes >or=4 years old. Among 354 selected ewes with clinically normal udder at the end of lactation, 28.8% had potentially pathogenic bacteria isolated from milk. The most prevalent bacteria were S. aureus (9.3%) and coagulase-negative staphylococci (9.3%). The risk of having a positive culture in at least one half was different between the two regions. Prevalence of ewes (n=261) with California Mastitis Test (CMT) positive result in at least one half was 24.1 and 14.9% using a cut-off of >or=1+ and >or=2+, respectively. Prevalence of culture-positive udder halves was 11.7% for CMT-negative compared with 53.6% for CMT 3+ halves. CMT status was positively associated with the isolation of coagulase-negative staphylococci, M. haemolytica, S. aureus, and various Streptococcus species, but not with other isolated bacteria. Additionally, prevalence of CMT-positive halves was higher in ewes from the Estrie region, aged of >or=4 years versus 1 year, having clinical mastitis previously detected in the lactation and/or with low body condition score. Lamb weaning weight was associated with CMT status of ewes, while weaning weight was not associated with milk culture results. More research is needed to understand the dynamic of milk SCC and IMI in ewes from meat-producing flocks, its economical impact and best ways to control it.

Campylobacter spp. were recovered from 660 (77.6%) of 850 swine cecal contents at the abattoir and from 24 (8.6%) of 278 specimens from sporadic cases of human diarrhea during the same period in the same geographical area. Campylobacter coli represented 95.7% of Campylobacter isolates recovered from pigs and 8.3% of those isolated from humans. Genetic profiles were determined by pulsed-field gel electrophoresis (PFGE) using KpnI enzyme to characterize the isolates in combination with phenotypic assays to detect production of cytotoxins, enterotoxins, and hemolysins. Among a subset of isolates (n = 10), up to five colonies from the same animal were characterized by PFGE. In 5 (50%) of 10 of the isolates, more than one genetic profile was observed per pig. Among the 100 isolates from pigs selected for further analysis, 81 different genetic profiles were observed, whereas 20 different genetic profiles were found among the 24 isolates of human origin. Cytotoxicity on Chinese hamster ovary cells was observed in 11 (11%) of 98 isolates from pigs and in 5 (21%) of 24 Campylobacter isolates from humans. No enterotoxin production was detected in Campylobacter isolates in this study, but 17 (71%) of 24 human and 61 (63%) of 97 pig isolates showed hemolytic activity. The study of genotypic and phenotypic profiles of swine and human isolates revealed no epidemiological relationship between isolates. The low genomic relatedness observed between groups of isolates and the weak toxicity level of swine isolates suggest that the hazard of contamination of humans by Campylobacter associated with swine production is low.

The efficacy of tilmicosin administered in the feed to control Actinobacillus pleuropneumoniae infections in pigs was evaluated through a multisite, multitrial study. For each of 6 trials, 48 pigs (stratified by weight and sex) were randomly assigned to 6 to 8 pens. Medicated feed containing tilmicosin (200 g/t) and unmedicated feed were randomly assigned at the pen level and were provided ad libitum from day -7 to trial termination (day 14). Seeder pigs (inoculated intranasally with A. pleuropneumoniae serotype 1 and showing signs of clinical disease) were introduced to each pen on day 0. Rates of death, gross lesions, and culture of A. pleuropneumoniae at necropsy, clinical scores, average daily gain in weight, and average body temperature were compared between the medicated and unmedicated pigs. Compared with the unmedicated pigs, significantly fewer (P < 0.05) pigs given tilmicosin had lesions typical of A. pleuropneumoniae or had A. pleuropneumoniae isolated from their tissues at necropsy. Together with a significant reduction (P < 0.05) in the average percentage of pneumonic lung involvement (both visually and by weight), there were reductions in the numbers of pigs with moderate and severe pneumonic lung lesions and with A. pleuropneumoniae associated mortality. With tilmicosin treatment, the average daily weight gain, daily temperature, abdominal appearance, attitude, and respiration were also significantly better (P < 0.05). The results of this study demonstrate the in vivo effectiveness of tilmicosin (200 g/t) in controlling pleuropneumonia among swine experimentally infected with A. pleuropneumoniae.

Streptococcus agalactiae remains an important pathogen of dairy herds in Québec, but data about antigenic characteristics of this microorganism are sparse. This study was conducted to determine the variety of S. agalactiae serotypes in dairy herds in Québec. Two hundred and ninety-five isolates cultured from the milk of individual cows from 7 regions of Québec were serotyped. Sixty-two percent of the isolates were untypable. Among the 38% of typeable isolates, serotype III was found most frequently. In conclusion, the heterogeneity found among antigenic determinants of isolates from bovine milk suggests that an immunological method for the detection of S. agalactiae performed directly on bovine milk would not be a practical approach.

A convenience sample of 234 colostral specimens, collected directly from the nursing bottle immediately prior to the first feeding, was studied. Samples originated from 6 farms and were collected over 24 months. Routine bacteriologic techniques were used to quantify the bacterial load of the colostrum, as well as to identify the bacteria. Overall, at least 1 microorganism was cultured from 221 colostral samples (94.4%). By using the upper tolerance level of 100,000 bacteria/mL, 84 samples (35.9%) were considered contaminated. Staphylococcus spp. (57.7%), gram-negative rods (47.9%), coliforms (44.0%), and Streptococcus uberis (20.5%) were among the most frequently isolated bacteria. The relative risk (RR) of contamination with more than 100,000 bacteria/mL was significantly greater in warm months [RR = 2.55, 95% confidence interval (CI): 1.63 to 4.02] than in cool months and in colostrum offered to male calves (RR = 1.55, 95% CI: 1.09 to 2.20). Bacterial load was also associated with the farm of origin (P < 0.0001). When assessing colostrum management, one should consider bacterial contamination. Multiple factors are likely associated with the degree of contamination, and farm-specific factors may be important. Further studies are necessary to evaluate the impact of bacterial contamination of colostrum on neonatal health.

Six beluga whales (Delphinapterus leucas) found dead on the shores of the St. Lawrence estuary had multiple slightly depressed greyish round areas randomly distributed over the whole body. Histologically, the surface of these areas was covered with a thick layer of Dermatophilus-like organisms which invaded the stratum corneum. The underlying stratum spinosum had marked spongiosis and vacuolar degeneration. Minimal neutrophilic infiltration was present within the underlying dermal papillae. To the authors' knowledge, dermatophilosis in cetaceans has not been reported previously.

The objectives of this study were the identification of the different contamination sources of Yersinia enterocolitica, as well as the determination of the prevalence and the distribution of the different genotypes in swine herds. The owners of 20 farms, located in the Richelieu-Yamaska region, agreed to participate in the study. Each farm was visited a minimum of 5 times between May and October 1997, and, at each visit, 20 environmental and 10 fecal samples were collected. Yersinia enterocolitica isolates were identified, serotyped, and submitted to a genetic characterization by pulsed-field gel electrophoresis. The correlation coefficient (0.61) between prevalence in environment and in feces was significant (P = 0.004). Among the 153 positive samples, 93.5% belonged to serotype 0:3. The comparison of PFGE profiles revealed that all environmental Y. enterocolitica isolates had a profile identical to that of isolates recovered in feces from the corresponding farms. Also, when the genetic profiles of isolates recovered from feces collected at the first visit were compared with the profiles of isolates obtained from the subsequent visits, the same profile was observed on every farm. We concluded that environment does not represent the main source of contamination of swine by Y. enterocolitica and that, in most instances, the same strain persists in a barn from one production lot to another.

Streptococcus agalactiae is considered one of the major causes of bovine intramammary infections. It is also found in the vaginas of women without any apparent clinical symptoms, but reports of neonatal infections, causing significant morbidity, are relatively frequent. The aim of this study was to evaluate the genetic diversity of S. agalactiae strains isolated from bovine milk and from asymptomatic women in Québec, Canada, by randomly amplified polymorphic DNA (RAPD) analysis. A total of 185 bovine isolates and 38 human isolates were first serotyped for capsular polysaccharide by double diffusion in agarose gel (bovine isolates) and coagglutination (human isolates). Strains were then studied by RAPD using 3 primers, designated OPS11, OPB17, and OPB18, which were selected from 12 primers. Thirty-eight percent of bovine isolates and 82% of human isolates could be serotyped. Prevalent serotypes were type III (28%) for bovine isolates and types V (26%) and III (24%) for human isolates. RAPD results showed that, taken together, all isolates (of bovine and human origin) shared 58% similarity. Ninety-four percent of these isolates were clustered in four groups (I, II, III, and IV) with 70% similarity among them. Three clusters, A (48 isolates), B (14 isolates), and C (32 isolates), with 79 to 80% similarity were identified within group IV, whereas the three other groups did not present any clusters. Despite some clustering of human isolates, relatively high diversity was seen among them. Relatively high heterogeneity was observed with the RAPD profiles, not only for field strains belonging to different serotypes but also for those within a given serotype.

In the spring of 1997, three large white hybrid turkey layer flocks of 52 wk of age experienced a severe respiratory condition. During the outbreak, the turkeys showed respiratory signs, an increased mortality rate, and an important drop in egg production. Macroscopic and histopathologic examinations were carried out on several carcasses, as well as bacteriologic analyses on different tissues. Colonies of Ornithobacterium rhinotracheale (OR) were detected after 24 hr of incubation, and the isolate appeared to be serotype A. The identification of the species was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole-cell proteins. Since 1993, several cases of OR infection have been diagnosed in the United States and more recently in Canada. Monitoring of this emerging infection is recommended.

Three dogs from different locations with acute renal failure were hospitalized in autumn 1996 and 1997. Leptospira interrogans serovar pomona was detected by the microscopic agglutination test. All dogs recovered after antibiotic treatment. The importance of the development of vaccines adapted to emerging serovars in dogs should be addressed.

Bacteriologic detection of Salmonella spp. from feces of animals admitted to Veterinary Teaching Hospital of the Faculty of Veterinary Medicine, University of Montréal, in Saint-Hyacinthe was carried out during a 1-year period to estimate the prevalence of bovine and equine salmonellosis. Prevalence at the time of hospitalization was quite low: 1.4% in cattle and 1.7% in horses. Incidence was 15.1 cases/100 animal/year in cattle and 38.7 cases/100 animal/year in horses. Serotype typhimurium was the most prevalent in both species. In cattle, cases were evenly distributed over the year. In horses, a recrudescence of cases and a obviousness of transmission were apparent in April 1996.

Salmonellosis due to Salmonella Give involving cows, a goat, and an ostrich over a 6-month period was investigated. Cases were found in 4 different regions. Antimicrobial susceptibility patterns, phagetyping, and pulsed-field gel electrophoresis analyses confirmed that all isolates belonged to the same clone. A common source of infection was suspected.

Raccoons may represent a source of leptospires for humans and domestic animals. We describe a case of severe interstitial nephritis associated with the serovar bratislava of Leptospira interrogans (1st report in wildlife), and the seroprevalence to 4 leptospire serovars in a recreational area in Quebec.

This study was undertaken to evaluate the prevalence of antibodies against Francisella tularensis, Coxiella burnetii, and certain serovars of Leptospira interrogans among trappers in Québec, Canada. Muskrat trapping was identified as a risk factor for F. tularensis infection, whereas having a cat at home apparently protected trappers against infection by L. interrogans. High percentages of control sera were positive for antibodies against C. burnetii (15%) and L. interrogans (5%), most frequently serovar bratislava. This is the first report of human infection by serovar bratislava in North America.

A total of 3306 isolates of A. pleuropneumoniae originating from lung tissues of pigs that died of acute pleuropneumonia and 140 isolates recovered from tonsils or nasal cavities of apparently healthy pigs from chronically infected herds were serotyped. Various serotyping methods, such as slide agglutination, tube agglutination, ring precipitation, coagglutination, immunodiffusion, indirect hemagglutination and counterimmunoelectrophoresis either alone or in combination were used. The techniques used for serotyping continued to evolve during the last 10 years depending on the problem encountered in serotyping. Antisera prepared in rabbits against formalinized whole cell suspensions of reference strains of A. pleuropneumoniae of serotypes 1 to 12 were employed for serotyping. Serotype 1 was predominant ranging from 55 to 87% from year to year during the last 10 years with an average prevalence of 68%. Serotype 5 was second in prevalence ranging from 9 to 30% with a mean of 23%. Both subtypes of serotype 5 (5a and 5b) were present in Quebec. Serotypes 3, 6, 7, 8, 10 and 12 were isolated in small numbers together accounting for about 9%. Serotypes 4, 9 and 11 were not present. Cross-reactions were observed among isolates of serotypes 3, 6 and 8, and 1, 9 and 11 and were easily differentiated from each other by quantitation of type and group specific antigens by coagglutination and immunodiffusion tests. Serotypes 1, 5 and 7 were isolated most frequently from tonsils of pigs from chronically infected herds. Prevalence of different serotypes in different countries has also been reviewed.

Seroprevalence of Actinobacillus (Haemophilus) pleuropneumoniae serotype-1 infection was evaluated in pigs on 7 farms in Quebec. Commercial cross-bred herds A to G, ranging from 110 to 235 sows and infected with A pleuropneumoniae serotype-1 were selected. Five pigs/litter were selected at random and were identified (group 1). Blood samples were obtained from group-1 pigs at 2 to 4, 14, 28, 42, and 56 days of age. Blood also was obtained from group-1 pigs remaining in the postweaning unit at 70 days of age, and from 20 to 40 sows 1 to 3 times. To determine prevalence of seropositive pigs in all age groups for the entire study period in herds C to G, blood samples were obtained from 20 pigs/age group (group 2) selected at random at 28, 42, and 56 days of age at each visit. Group-1 pigs were included when they reached 28, 42, and 56 days of age. Pigs were serologically monitored in herds A and B for 3 months and in herds C to G for 5 to 6 months. Serologic status of pigs at 2 to 4 days of age was not statistically associated with status at 42 days (P = 0.6293) and at 56 days (P = 0.3098) of age for the same pigs. Therefore, seronegative pigs 2 to 4 days old did not seroconvert earlier than did those with detectable maternal antibodies at 2 to 4 days old. Only about 50% of the 70-day-old pigs were seropositive at 56 days. Seemingly, pigs seroconverted late in the postweaning period.(ABSTRACT TRUNCATED AT 250 WORDS)

A total of 349 isolates of Streptococcus suis retrieved from different tissues from diseased pigs were examined in this study. Only 48% of them could be categorized as one of serotypes 1 to 8 and 1/2. Among typable isolates, serotype 2 was the most prevalent (23%), followed by serotype 3 (10%). The majority of all isolates originated from lungs, meninges/brain, and multiple tissues. Forty-one percent of typable isolates and 33% of untypable isolates were retrieved in pure culture. Other isolates were found in conjunction with Pasteurella multocida, Escherichia coli, Actinobacillus pleuropneumoniae, Actinomyces pyogenes, and other streptococci. Typable S. suis isolates were more frequently isolated from pigs between five and ten weeks of age, while untypable isolates were mostly found in animals aged more than 24 weeks. No obvious monthly and/or seasonal variation of the prevalence of isolation of S. suis could be detected.

Serological tests for the detection of antibodies against Haemophilus somnus were carried out in herds of beef and dairy cattle using three different techniques: agglutination, complement fixation and counterimmunoelectrophoresis. The agglutination test appeared to detect more seroreactors than the complement fixation and counterimmunoelectrophoresis tests. Results of the three tests indicated that there were more positive reactors in beef cattle and dairy cattle from infected herds than in dairy cattle from clinically normal herds.

To evaluate the relative importance of the various enteropathogens causing neonatal diarrhea in Quebec farrowing operations, observations were made on 749 diarrheic pigs from 325 outbreaks of diarrhea. They were one to 15 days of age, and were obtained alive for necropsy generally within 48 hours of the onset of diarrhea. Some pigs were from severe, explosive outbreaks of diarrhea with high morbidity and mortality rates, while others were from herds with chronic neonatal diarrhea with lower morbidity and mortality rates. A combination of bacteriological, virological and histological methods were used to study the pigs. Viruses were incriminated in 60%, bacteria in 23% and coccidia in 15.3% of the 325 diarrhea outbreaks. Transmissible gastroenteritis virus was by far the most common enteropathogen with a prevalence of 52%; rotavirus was implicated in 9.2% of the outbreaks while adenovirus was incriminated in 0.30% of the outbreaks. Enterotoxigenic Escherichia coli were involved in 22.4% of the cases while Clostridium perfringens type C was an occasional finding. Coccidia involved in our herds were identified as Isospora suis. The disease was attributed to infection with a single etiologic agent in 590 diarrheic pigs (78%) while combinations of agents were present in only 90 (12%). The age-specific occurrence of the various enteropathogens was evaluated. Transmissible gastroenteritis virus was the most common enteropathogen in all age groups. Colibacillosis was common in pigs which became diarrheic under five days of age; in this age group, the enterotoxigenic E. coli were frequently found alone, but were usually combined with other agents in older pigs. The prevalence of coccidia was high in pigs which became diarrheic between five and 15 days of age. Rotavirus infection was common in diarrheic pigs older than ten days of age. Although individual baby pigs were commonly infected with a single enteropathogen, it was very common to see more than one agent involved in an outbreak of diarrhea, particularly when pigs of different ages were affected. Observations on the occurrence of the enteropathogens according to the seasons were also made. Occurrence of transmissible gastroenteritis was throughout the year with the highest prevalence during the fall, winter and spring months. Colibacillosis and coccidiosis were more common in the summer, fall and early winter months with the lowest prevalence in the spring months.

A serological survey for canine brucellosis has been conducted on 341 dogs from different regions of the province of Quebec. A significant titer was found in six sera (1.6%) with the 2-mercaptoethanol tube agglutination test. Only two dogs presented titers >/= 1:200 which is considered as indicative of active infection.

The prevalence of antibody to bovine respiratory syncytial virus in Quebec and the role of the virus in a respiratory disease outbreak was investigated. The indirect immunofluorescent, neutralization and haemagglutination inhibition techniques were used to carry out this study. Of the 1,444 adult animals examined 519 (35.9%) had antibody to bovine respiratory syncytial virus. These positive reactors were found in each agricultural region of Quebec. The highest (53.0%) and the lowest (21.8%) prevalence was observed in the sera collected by the laboratories of St. Hyacinthe and Sherbrooke. During a respiratory disease outbreak affecting 77 calves on a farm, bovine respiratory syncytial virus was shown to be associated with infectious bovine rhinotracheitis, bovine parainfluenza type 3, bovine viral diarrhea viruses and bovine adenovirus type 3 as detected by seroconversion. Of the 38 seroconverted animals 14 were seropositive to bovine respiratory syncytial virus.

A survey to detect Streptococcus suis serotype 2 in 1,716 weaned pigs was done in Quebec. Forty-nine sow herds were included in this survey: in 26 herds, S suis serotype 2 had been isolated during the preceding 12 months and in 23 herds (control), the organism had not been detected during a previous study. Swab specimens of the nasal cavity and tonsils of pigs were obtained for bacteriologic culture, and S suis serotype 2 was easily detected by the use of brain-heart infusion agar containing a Streptococcus-selective supplement and 5% goat antiserum raised against S suis serotype 2. After measurement of the diameter of the precipitation zone of 539 isolates, a slide agglutination test was performed to identify the S suis serotype 2 isolates. The mean precipitation zone diameter obtained for group S suis serotype 2 was larger (P less than 0.001) than that for the group designated as "others". With slide agglutination test results as reference and on the basis of discriminant analysis to stimulate detection of S suis serotype 2, 93.1% of all isolates were correctly classified, using the precipitation zone diameter as unique classification criterion. Relative specificity was 94.5% and relative sensitivity was 88.7%. Use of the precipitation zone diameter on a quantitative basis led to the proposal of a simple and reliable technique to screen swine herds for S suis serotype 2 in weaned pigs. Nasal and tonsillar swab specimens were obtained and analyzed concurrently for S suis serotype 2. The organism was found in both sites in only 20.4% of 103 carrier pigs.(ABSTRACT TRUNCATED AT 250 WORDS)

During a period of 30 months, from January 1977 to June 1979, Leptospira agglutinins were detected in 355 (6%) of 5841 bovine sera, 52 (10.1%) of 511 porcine sera, one (5%) of 20 equine sera and one (12.5%) of eight canine sera. Bovine, porcine and equine sera reacted predominantly with L. pomona. Reactors to L. hardjo/sejroe, L. icterohaemorrhagiae and L. grippotyphosa were also detected in cattle. One porcine serum reacted with L. grippotyphosa and one canine serum with L. icterohaemorrhagiae. Al the sera originated from suspected cases of leptospirosis.

An important reduction in the in vitro efficacy of spectinomycin and chloramphenicol was recorded between 1981 and 1986 against the causal agent of porcine pleuropneumonia Actinobacillus. Antimicrobial susceptibility tests were carried out by use of Kirby-Bauer disk diffusion technique on a total of 723 isolates of Actinobacillus pleuropneumoniae. Results did not agree with those of other reports in which a constant susceptibility to any of the antimicrobial agents tested was reported with serotype 2 isolates. The ability to acquire drug resistance may differ from one serotype to another.

Blood samples were obtained from 208 moose in La Vérendrye and Matane Reserves and in Laurentides Park, Quebec, Canada. Sera were tested for antibodies to Brucella abortus, Leptospira interrogans serovar ballum, canicola, grippotyphosa, hardjo, icterohaemorrhagiae and pomona, and Francisella tularensis. Fifteen sera contained evidence of prior exposure to F. tularensis. Only one animal was a seroreactor to L. interrogans serovar grippotyphosa and none of them had antibodies to B. abortus.

Serological studies on Haemophilus somnus infection were carried out on 1795 cattle from 231 dairy herds in the province of Quebec. An epidemiological investigation was done in each of the dairy operations. Seroreactivity rate and mean log2 titer for all the sera were 55.4% and 4.1620 respectively. Cattle from eastern regions of Quebec demonstrated the lowest prevalence of H. somnus agglutinins. The percentage of seroreactor animals was 60.3 in herds of 100 cattle or more in comparison to 53.2 in herds of smaller size. About 75% of the animals from 16 herds in which one or more cattle showed nervous manifestations of undetermined origin over a one year period had antibodies to H. somnus. Herds in which respiratory diseases occurred had 59.6% seroreactor animals and herds in which weak calf syndrome was diagnosed over a one year period had 61.4% seroreactor animals. In 87 herds located within 20 km of feedlots, 61.8% of the sera had titers and the mean log2 titer was 4.4813.