by Elizabeth A. Tomlin
Producers came from as far away as Hoosick Falls, NY to attend a presentation about multi-drug resistant Salmonella Dublin at Cornell Cooperative Extension (CCE) of Oneida County, where Marylynn Collins, Dairy & Livestock Educator, CCE Oneida County, teamed up with NYS Ag & Markets, Dr. Melanie Hemenway and Dr. Patrina Ashley, NY State Cattle Health Assurance Program (NYSCHAP) to inform producers on symptoms, management and prevention practices associated with this deadly disease found in both beef and dairy cattle.
“Calves die fast,” said Dr. Hemenway, NYSCHAP Coordinator.
Hemenway explained that once the disease starts it’s hard to stop and will often wipe out whole groups of calves.
People are also at risk as the disease jumps between species and has been reported to have been responsible for canine death.
The disease is endemic in states west of the Mississippi River, and folks who send calves off to endemic states for “back-grounding” or to be raised until breeding age, may be bringing the disease back to their herds.
The disease has increased across New York.
Salmonella Dublin bacteria is resistant to 17 antibiotics and can hide dormant in adult carrier animals, who shed the bacteria and spread it through bodily fluids and waste, including manure, urine and vaginal secretions, as well as through the infected cow’s milk and colostrum. It can become systemic in adult cattle; affecting their blood, liver, kidneys and other organs, and has been found in afflicted animals’ lymph nodes. It may be passed in-utero and is also shed in infected bone marrow. Unexplained, spontaneous abortion in cows is one symptom to watch for.
Calves infected in-utero or through contaminated colostrum and milk will first display extremely high temperatures.
“High fevers are indicative of Salmonella Dublin,” said Hemenway, who reports having seen temperatures in calves at 106 degrees.
“Salmonella Dublin is different than your typical Salmonella diseases. It’s actually more airborne and it creates a respiratory disease. Rarely do we see diarrhea and intestinal involvement. Calves are most infected. That’s where you are going to see the impact. You’re going to see high respiratory disease and you’re going to see high death losses.”
Diarrhea may develop later in the disease — if the calf survives long enough.
Calves quickly become septic, with the disease rapidly entering their bloodstream.
One attendee reported a recent experience with a large calf-raising facility in Central New York where about 30 percent of the calves on the farm were lost before the Salmonella Dublin bacteria was discovered by Cornell as the cause.
Calves born from infected cows may appear fine at birth and die suddenly.
Although most producers think of common respiratory diseases and viruses when they see the symptoms, it is critical to consider Salmonella Dublin as a possible cause.
Because the disease is multi-drug resistant, there is generally no response to typically used antibiotics.
Animals that do survive will generally be unthrifty and become carriers, shedding the bacteria and contaminating herd mates.
Symptoms may be seen in newborn calves or calves up to about 8 months old, and can be brought on by stress, as when moving calves to a new group or location, or even a change in weather.
Strict bio-security is critical to avoid contracting and spreading this disease. Wear gloves when handling sick calves and any aborted placentas or membranes.
“The placenta and the fluids from the abortion contain a massive amount of bacteria,” emphasized Hemenway.
These materials can be useful for diagnostics for up to 2 weeks after abortions occur. However, remember that these materials are highly contaminated and handle them with care.
They must also be kept away from other animals, including companion animals.
Maternity pens should always be kept clean and disinfected to avoid possible transmission of this — or any — bacteria and disease.
“Your maternity pen environment is very critical,” stressed Hemenway. “It should be as clean and dry as you can get it, well ventilated and not overstocked. So that calf is born in as clean an environment as possible and if you can get that calf out of that environment as soon as possible, you can minimize that exposure from those adult animals.”
If the calf has been exposed in-utero and is then placed in a mingled-calf, group housing; this calf will contaminate the other calves. Individual calf housing is preferred, minimizing a potentially disastrous situation.
Embryos used in embryo transplants may also be capable of harboring this bacteria.
Wet conditions and environments promote growth of Salmonella Dublin, which has also been discovered thriving in ponds and pastures.
Be wary of using milk or colostrum from other farms — even in the case of emergency.
Always keep boots and clothes clean and disinfected. Do not allow other folks to walk through your barns or calf areas unless wearing clean, protective coverings over their footwear.
Because Salmonella Dublin is air-borne it can be aerosolized through pressure washing and inhaled by workers who pressure wash contaminated calf hutches or other contaminated equipment. So, be sure to provide workers with protective equipment when pressure washing.
Infected cows pass the bacteria in their milk and people drinking raw milk are at danger.
“Raw milk is definitely a vehicle for people to get sick. Pasteurization will take care of it.”
Calves fed raw milk are also at danger.
Prevention is critical.
Be proactive about screening for this disease and keep it off your farm to avoid the huge financial impact and the stress it causes. Calf handlers are seriously impacted by the devastation this disease creates.
When purchasing animals — including bulls — be sure to test them before adding them to your existing herd. If possible, test before purchase. Always quarantine.
Additionally, show animals are at risk and can be infected when at showgrounds. Therefore, it is always wise to isolate animals when returning home from shows and make sure your boots, etc., are clean before handling your other animals.
Contaminated manure from other sources can potentially impact your livestock. This includes livestock trailers.
A cost-effective Salmonella Dublin blood test is available through the Cornell University College of Veterinary Medicine’s Animal Health Diagnostic Center.
Bulk tank samples or milk samples taken directly from cattle can also be used for testing.
For more information contact Hemenway at Melanie.Hemenway@agriculture.ny.gov or call 585.313.7541.