A disease that could cause death in cattle is being reported to veterinarians, indicating a need to get more producers to understand what the disease is and how to combat it, a pair of Ohio State University Extension experts said.
Bovine anaplasmosis is a bloodborne disease that could cause severe anemia shortly after a cow is infected, which in some cases results in death or abortions, said William Shulaw, an OSU Extension beef/sheep veterinarian. And cows that recover from the disease become a lifetime carrier of the bacteria that causes it unless it is successfully treated, he said.
The disease is typically transmitted through biting flies and blood-contaminated inanimate objects such as hypodermic needles, some tagging instruments, surgical instruments, nose tongs, and possibly tattoo equipment, Shulaw said.
Although there is a disease called "anaplasmosis" in human beings, it is not the same, and the disease in cows is not transmitted to humans, he said.
"Most cases are reported in the fall, which suggests that horseflies are a common vector for the disease in [the Ohio] region," Shulaw said
"Incubation is a few days to a couple of months, but it can occur any time of the year when the disease is transmitted."
Animals that develop the clinical signs of anaplasmosis are usually older than a year, and the signs usually begin with a fever of about 104 degrees or higher, Shulaw said.
"The red blood count can fall very rapidly and animals can become severely anemic in just a few days," he said. "As the anemia progresses, the animal gets weak, reduces or refuses feed intake, and becomes lethargic."
Lack of oxygen to the animal's brain resulting from anemia may cause it to act aggressively or behave abnormally, Shulaw said, noting that cows in advanced pregnancy may abort.
Treatment with injectable tetracycline will usually halt an outbreak in a herd and may prevent the development of severe anemia in an animal already incubating the disease, he said.
"It can be a large loss and take a while to get the disease under control," Chris Penrose, OSU extension educator, added. "It's been around for a while but people are just now becoming aware of it even though it has caused some significant impact in some Ohio herds in recent years.
"Knowing what to look for is important because a well explained death may be better than a poorly explained recovery. If we know why the animal died, we could potentially know how to prevent it in other animals."