Monday | October 16, 2017
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Disease forces quarantine of cows on island


Stephens Media

Eight Big Island cattle ranches are under a quarantine, following an outbreak of a bovine venereal disease.

The rancher in whose herd the first infection was identified last year said he would like to see Hawaii follow the examples of several mainland states, which require routine testing of all bulls for the disease, Tricomoniasis. Ka‘u rancher Kyle Soares, who discovered the first cases of the disease in his herd in 2010, said he asked the Department of Agriculture to implement such a requirement.

“Their answer is they’re testing in the slaughterhouse,” said Soares, whose ranch was quarantined last year. (The testing has) got to be at the front of the deal.”

Soares also questioned how much information state agricultural officials are passing along to island ranchers.

Tricomoniasis passes from infected cow to bull, or vice versa, and can cause a pregnant cow to abort the fetus or for the fetus to “mummify” within the cow’s uterus, Department of Agriculture Veterinarian Program Manager for the Animal Disease Control Branch Jason Moniz said. The disease doesn’t transmit to humans, he said.

Testing the animals at the time of slaughter “allowed us to get a picture of bulls from throughout different parts of the state,” he said. “It’s an easy place. You don’t have to restrain a live bull.”

Moniz said the department mailed letters to ranchers after the first cases were detected in 2011. He also talks with ranchers in the areas most affected about testing their bulls.

“For ranches that are in the hot areas, I’ve cautioned some,” Moniz said. “We let them know where the infected herds are and the hotspots are. (For those farmers), it would be smart to test annually.”

So far, 10 ranches around the state have been quarantined and one has already been able to lift the quarantine, after proving the infection rate had dropped, Moniz said. One is on Oahu, two near South Point, four near Naalehu and two are in Kohala. Overall, infection rates on the island are relatively low, he said.

Ranches under quarantine must remove the infected bulls and not breed the cows, Moniz said. They can’t mingle their cattle with cattle from other ranches, either. The cows are kept separate from uninfected bulls for 120 days and then allowed to breed. The bulls are tested, again, for the infection after that, to see if the cows are still infected or have recovered, which Moniz said happens without treatment, after the cow’s uterus cleans itself out.

Tricomoniasis is more common in Western states than the eastern United States, Moniz said. Each state has its own rules about how to deal with the disease.

“We tried to find one that would fit us,” he added. “We chose a program right in the middle.”

He recommends ranchers not purchase bulls without having the animals first tested for the disease and not to purchase cows that are not pregnant. Ranchers could also purchase animals which have never been bred, Moniz said, because they will not have been exposed to the disease.

Bulls don’t exhibit any symptoms, but ranchers may notice a drop in the rate at which their cows become pregnant if the herd is infected, he said. In a typical herd, during good weather, about 90 percent of cows should become pregnant during breeding season. That number could drop to 60 percent to 70 percent because of Tricomoniasis, he said, although drought conditions may also decrease cows’ fertility.

Soares said he regrets agreeing to the quarantine, especially after seeing neighboring ranches also have cases of the infection.

“I should never have signed it,” he said. “You sign it, you’re committed to it, but there’s never any information.”

He said the Hawaii Cattleman’s Association isn’t doing much about the problem, either.

Attempts to reach the Hawaii Cattleman’s Association and Parker Ranch Thursday were unsuccessful.

Email Erin Miller at


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