Calf Talk

April, 2008

Volume 14, No. 4

SALMONELLA DUBLIN PNEUMONIA

By: Russ Schnepper, D. V. M.

Salmonella dublin is a very potent pathogen and very difficult to get rid of.

Where does Salmonella come from? On a dairy farm the usual source is manure from infected cows. Cows that do not appear ill may be subclinically infected and shedding Salmonella. A few cows may shed Salmonella organisms all their lives. Other sources of infection are birds (including waterfowl), flies, cats, dogs, raccoons, and rarely people. Salmonella organisms are in the manure, saliva, nasal secretions, milk and colostrum. Dublin can be aerosolized by normal breathing and coughing, especially in buildings.

Salmonella survives outside animals in contaminated feed, manure and water. Under appropriate moisture, temperature and pH conditions Salmonella can replicate about every 30 minutes. In the environment, it survives for 4 to 5 years in water, soil, dust, and moist areas out of direct sunlight and on or within foods. Dublin can survive in dry manure for over a year, however freezing at -4 Fahrenheit kills 85% of the Salmonella in 2 days. Crops irrigated with salmonellae-contaminated wastewater will lead to contamination of forages and water sources. Rendering kills Salmonella. The rendered feed can be contaminated after it has been processed. Cattle trucks and trailers are a very common source of Salmonella. The driver of the truck, picking up calves from more than one source, should not enter the calf raising facilities.

There are several sources of Salmonella infection in the calves: A calf will most likely find its first exposure to Salmonella in the maternity pen or calving area bedding, if it is there long enough to make attempts to stand. A pea sized piece of manure contains enough Salmonella to infect the calf. Calving cows that are sick with Salmonella shed the organisms in the colostrum. Esophageal feeders, buckets, bottles and all equipment used with the calf can be sources of infection. Communal warming or drying areas and transport vehicles that are used to move the calves, are a source of infection. The incubation period for Salmonella Dublin may vary from several hours (in case of an extremely heavy exposure) to a few weeks. Most of the cases I have observed have been in calves that were four or more weeks of age. Many diagnostic tests may miss the Salmonella, even when there are very obvious postmortem signs. So the diagnosis is still a clinical one. There is no commercially available blood test for Salmonella Dublin. Disinfection with Synergize is helpful. A disinfectant “Oxy-Sept 333" by Ecolabs appears promising and can penetrate soil, as under hutches, etc.

Our current vaccination protocol is to vaccinate with one milliliter of SRP at four weeks. Give BoSe or MuSe and Immunoboost at the same time. (A selenium deficient animal will not respond to vaccines nor Immunoboost.) Then repeat the SRP and Immunoboost two weeks later. In severely infected groups and/or facilities, a third dose of SRP two weeks later is beneficial. The first SRP can be given at day 8 in colostrum deprived calves.

Dublin primarily causes a respiratory problem. Somewhat effective treatment drugs are: SMZ-TMP or Uniprim (in non ruminating calves, as the trimethoprim is inactivated in the rumen) ,or Nuflor, Excenel or Baytril (not in veal). Immunoboost is a good treatment and can be repeated in seven days.

Contact information for ordering information and questions about our products:

Schnepper International, Inc.

3210 County B, Platteville, WI 53818

608-348-6141, Fax: 608-348-6146