An Outbreak of Toxoplasmosis in an Ontario Chinchilla Herd

An outbreak of toxoplasmosis which killed 44 of a herd of 56 chinchillas and produced 4 abortions with the loss of a total of five fetuses is reported. A wild mouse thought to be the house mouse (Mus musculus), caught in a trap in the basement housing the chinchillas, was found to be infected with Toxoplasma gondii. The suggestion is made of the existence of a reservoir of infestation in wildlife with wild rodents implicated in this case as possible transmitters of the disease. The post mortem findings, histopathological, serological, and bacteriological results of work done on 6 dead and two live chinchillas and the wild mouse are also reported. A brief review of the literature dealing with toxoplasmosis in this species (Chinchilla lanigera) is presented.     

Twenty Years of Experience with Dairy Herd Health in Ontario

This article expresses observations on planned herd health for dairy cattle, based on experience gained in the Ambulatory Clinic practice of the Ontario Veterinary College. The author and his colleagues, especially Dr. R.A. Curtis, have initiated and delivered a preventive medicine approach to veterinary practice in the teaching program and teaching practice for the past 20 years. In addition, herd health presentations have been made to veterinary associations in every province in Canada and to many breed associations and producer organizations. The Canadian food animal veterinarian and his clients have been informed at meetings and by the media of the need, objectives, methods and benefits of dairy herd health and many veterinary practices now offer programs to their clients. Herd health has become a household word in Canada's dairy practices and dairy farms.

A formal herd health program is an important step to achieving total health management; but maximum returns on investment can only be realized after three or four generations of cattle have been reared on the program.

In conclusion, herd health practice has been a very satisfying aspect of veterinary medicine and a profitable and valued service for our clients. Maintenance of health involves the application of all knowledge and procedures which veterinarians have to offer.

     

The Successful Management of Leptospirosa hardjo Infection in a Beef Herd in Northern Ontario

Abortion, premature calving, hemolytic anemia and fatal hematuria were associated with high levels (titer > 10(-4)) of antibody to Leptospira interrogans serovar hardjo and with isolation of hardjo in a herd of 265 beef cattle in the Great Clay Belt of northern Ontario. This herd was bred by artificial insemination, after heat detection by vasectomized bulls. The antibody prevalence rate in the herd was 54 to 60% over a five year period. The rate tended to reach 100% by age three years and to be below 5% in yearlings, which were raised in isolation from older cattle. Hardjo was isolated from the urine of a cow that aborted in the eighth month of pregnancy, and from kidneys of yearling steers which had been exposed to an older cow. Maternal antibody levels in calves paralleled those in their dams, protecting calves while they were being naturally exposed to infection, thus contributing to the achievement of balance between host and parasite. A controlled vaccination trial was conducted in 50 initially seronegative yearling steers and heifers. Serological response to vaccine was limited to a maximum agglutinin titer of 10(-2) in 8% of vaccinated cattle. Vaccination reduced the infection rate from 86% in the controls to 46% in the treated group, indirectly reducing the number of calves for which colostral antibody against hardjo would be available. A vaccination program was not implemented in the herd. Hardjo infection appeared to die out over a period of six years following the initial five year study period, with antibody prevalence falling from 60% to 0.7% and reactors persisting only in two eight year old cows. Decline in infection was coincident with changes in management which protected heifers from exposure to infection until their third pregnancy, and which probably lowered the reservoir of infection by increased culling from older age classes.     

Demonstration of Generalized Infection with Caprine Herpesvirus 1 Diagnosed in an Aborted Caprine Fetus by PCR

Veterinary Research Communications -     

Mycobacterium avium subsp. paratuberculosis Detected in the Reproductive Tract of Cows from an Infected Herd

Mycobacterium avium subspecies paratuberculosis (MAP), the causal agent of paratuberculosis, was detected by quantitative real‐time IS900 PCR in the follicular fluid from the reproductive tracts of cows originating from one infected herd. As well as being detected in follicular fluid of cows shedding bacteria in their faeces, MAP was also detected in the follicular fluid of one apparently healthy, non‐shedding individual cow. The finding of MAP in follicular fluid is unexpected and could contribute to the lower viability of embryos and resultant lower pregnancy rate. In addition to finding contaminated follicular fluid, vaginal and uterine flush fluids were determined to be positive for the presence of MAP in 75% and 56.3% of the time of the cattle currently shedding MAP in their faeces, respectively. The presence of MAP in different parts of the reproductive tract was seen in clinically as well as subclinically infected cows. These findings extend our currently scant and contradictory knowledge about the dissemination of MAP in the reproductive tract of female cattle.     

beta-Mannosidosis in a Salers calf: a new storage disease of cattle

A storage disease characterised by widespread vacuolation of cells throughout the body was diagnosed in a newborn calf of the Salers breed. Extraction and analyses of water soluble material showed that the storage material was oligosaccharide in nature and was probably derived from the core region of the heterosaccharide moiety of glycoproteins. Glycosidase analyses showed that the disease was due to a deficiency of acidic beta-mannosidase.     

羊和猪胎盘肽的提取

利用超滤法从羊和猪的胎盘中提取胎盘肽,用改良的加脲Tricine-SDS-PAGE电泳法对其进行初步定性鉴定。成功分离显示出了羊的胎盘肽,其分子质量小于5 ku,与人胎盘肽的分子质量范围完全符合。猪的6 ku的蛋白带很明显,但低于5 ku的蛋白带不是很明显。     

Salmonella investigation in an Ontario feed mill.

The frequency of Salmonella contamination of feedstuffs and finished broiler chicken feeds at an Ontario feed mill were investigated over a four-month period. Samples of feed ingredients and finished pelleted feeds were collected at various points during manufacture and cultured in trypticase soy broth prior to selective enrichment for isolation of Salmonella. Salmonella contamination was found in 4.3% of 93 finished pelleted broiler feeds examined. The contamination appeared to result primarily from the incorporation of contaminated animal protein ingredients into the feed. Meatmeal and the broiler, premix, which contained meatmeal as a filler, were most frequently contaminated followed by feather meal. Pelleting failed to eliminate the Salmonellae from the feeds. The methods used failed to detect Salmonella in the environment of the feed mill or its delivery trucks. Recommendations for control are made.     

Use of an Immunobinding Test on Nitrocellulose Paper to Diagnose Caprine Brucellosis

Veterinary Research Communications -