Scours is a common ailment for many producers, yet they may not know that some strains of scours are zoonotic.
A zoonotic disease is one that can be transmissible from an animal to a human, meaning a producer or member of the family can become ill because of an outbreak of scours in the pasture.
“There are multiple causes of calf scours that are zoonotic ,” said Tahnee Syzmanski, the Montana assistant state veterinarian.
These include cryptosporidium, campylobacteriosis, salmonella and E. coli.
“E.coli is not on our list as reportable, but certain types of E.coli are zoonotic and producers need to be aware of that,” said Syzmanski.
Dr. Layton, with the Montana State Diagnostic Lab, said that all cattle carry E.coli naturally and that it may not cause disease in cattle. The problem comes when cattle and other animals shed 0157:H7. This particular bacterial strain can cause severe intestinal disease in man that can lead to kidney failure and other complications. Younger children and older adults are the most susceptible to this strain.
On the bacterial level of scours the two most common and significant zoonotic pathogens in calves are salmonella and cryptosporidium.
“Both can result in high morbidity and mortality in calves and produce severe intestinal disease in man,” said Layton.
According to Syzmanski, not all strains of salmonella that cause diarrhea in calves will cause sickness in humans, but some strains of salmonella certainly are capable of making people sick.
Salmonella in humans will show up as nausea, vomiting, abdominal cramps which are often severe, diarrhea, fever, chills, headache and, at some advance stages, blood in the stool. While the main symptoms last about a week, it can take the human system months to fully recover.
“Salmonella can cause protracted diarrhea, dehydration and even get into the circulation,” said Layton.
Cryptosporidium is another type of scours that can be transmitted to humans.
“We’ve had pre-vet students and ranchers get infected with it,” said Layton. “If a rancher has been previously exposed to the agent, in all likelihood, that person has developed a protective immunity and will not develop diarrhea. Immune-naïve individuals, such as urban dwellers, children or those with compromised immune systems caused by chemotherapy or infectious diseases such as HIV, are most susceptible to developing the disease.”
According to the CDC, people and animals can get infected with cryptosporidium when drinking contaminated water or eating contaminated food, or by direct contact with infected persons or animals.
About 50 percent of dairy calves are infected and shed cryptosporidium. Infection in humans can cause diarrhea and abdominal cramps.
Because some types of scours can be transmittable to humans, producers should know what they are dealing with. Different types of scours respond to different types of disinfectants and cleaning processes.
During calving or while treating calves with scours, follow proper sanitation practices such as wearing disposable gloves when handling or treating animals.
Producers need to clean and sanitize equipment that has come in contact with sick animals, their bedding or their pasture areas.
Do not let fecal matter touch the mouth of humans. That means making sure hands are washed before eating, drinking or wiping the face. This is especially important when children have been around the area and have possibly been exposed to fecal material.
Do not allow shoes or boots to track fecal material into the house.
If a family member gets sick with diarrhea or abdominal cramps, be sure to inform the doctor if there has been any exposure to livestock, especially ones with scours.
“It’s extremely important for producers to know that some types of scours are zoonotic, that they can become infected by them,” concluded Syzmanski.