BE ALERT FOR ANAPLASMOSIS
By : Laura Handke
Gregg Hanzlicek, director of production animal field investigations, Kansas State University, provided a review of anaplasmosis for producers attending the 2019 KOMA (Kansas, Oklahoma, Missouri and Arkansas) beef conference. He said, “that anaplasmosis is confirmed in every district of Kansas, a periodic review of the disease, its clinical symptoms, treatment options and prevention is a warranted discussion.”
“Anaplasmosis is a bacterial infection and any time I talk to bovine producers, I always tell them, ‘If you hear a disease is caused by a bacteria, at least that gives you some idea that there might be a treatment.’ And for anaplasmosis, there is, indeed, a good treatment,” says Hanzlicek.
Hanzlicek told producers that the take-home messages for his presentation were:
1. All ages of cattle can become infected with anaplasmosis, and the earlier in life infection occurs, the better.
2. All treated and recovered cattle will remain life-long carriers of anaplasmosis. Treatment does not eliminate the carrier stage.
3. Producers should proactively take measures to prevent and manage the infection of cattle with anaplasmosis.
Although cattle can become infected at any age, clinical symptoms typically present in animals older than two years of age.
“A typical indication [of anaplasmosis infection] is if you go out and check cows on a Saturday, and then go back on Wednesday to find one or more adult cows or bulls dead in the pasture—that’s a classical sign that you have anaplasmosis. There aren’t a lot of things that kill adult bovines,” Hanzlicek says.
Anaplasmosis symptoms can also mimic bovine respiratory disease, causing open-mouth breathing in cattle, as the animal works to force more oxygen into its lungs. A lack of oxygen, however, is not the cause of the symptoms, but rather a shortage of red blood cells needed to move the oxygen to the tissues.
“An anaplasmosis infected animal will often exhibit aggressive behavior,” says Hanzlicek. “The aggression occurs because the brain is starved of oxygen.”
Other signs that cattle may be infected may be high numbers of abortions, especially in fall calving herds and icterus, or the yellowing of the whites of the eyes. Infected cattle will present with an enlarged spleen when posted; Hanzlicek recommends that all suspected cattle be posted if anaplasmosis is suspected so management measures can be taken to prevent additional deaths.
Preventing the spread of infection
Today, every state, except Hawaii, has had confirmed cases of anaplasmosis, however proactive prevention and management can determine the extent of detriment the bacteria has on an operation.
A major contributor to the spread of anaplasmosis, the male American Dog Tick allows the bacteria that causes anaplasmosis to reproduce in all of its tissues— turning a meal of thousands of infected blood cells into billions of infected blood cells.
“Eventually the saliva glands will become infected so that when the tick is feeding the saliva will infect the non-infected animal,” Hanzlicek says. And while some may question the prevalence of infected ticks, Hanzlicek shares that in a 2018 study, of the first 520 ticks trapped and tested in eastern Kansas, 35% tested positive for anaplasmosis.
Other blood-feeding insects known to transmit anaplasmosis, horseflies, stable flies, and deerflies, are of less concern than the American Dog Tick because those insects do not allow the bacteria to replicate in their tissues.
Poor chute-side protocol has also been identified in the spread of anaplasmosis between infected and uninfected cattle.
“If you have a positive animal in the chute and there is a negative animal behind, you have a 60% probability that animal will become infected if the same needle is used,” Hanzlicek told producers. He is referring to a study where two percent of the blood cells of one animal were infected, followed by subcutaneous injections of 10 non-infected animals. A 60 day assessment of the fly and tick isolated animals found that six of the 10 cattle tested positive for anaplasmosis.
Anaplasmosis can also be transmitted to the calf through the placenta, with research showing approximately 11-15% of calves born to a positive cow will Also test positive for the bacteria.
For anaplasmosis and all infectious diseases, Hanzlicek suggests that a producer consult their local veterinarian to assess the situation and aide in putting together a plan of action. He also cautions that the biggest losses typically occur when a negative herd becomes infected and advises that all animals coming into the herd be tested—animals
can be tested for anaplasmosis at any age.
As with any disease, prevention remains the most effective mitigation of loss from anaplasmosis. Using a new needle between every injection, feeding chlortetracycline in 30 day rotations and controlling flies and ticks are all recommended in a proactive protocol for the control of anaplasmosis.