The USDA is recommending testing dairy herds for H5N1 bird flu virus (HPAI) prior to moving the livestock between states.
“We are strongly recommending testing before herds are moved between states, which should give us more testing information and should mitigate further state-to-state spread between herds,” said the Animal and Plant Health Inspection Service, the USDA animal health agency.
According to APHIS, a mandatory testing program for the 26,000 U.S. dairy herds would not be practical or feasible, saying, “Right now, we are seeing that a small portion of the affected herds are becoming ill and that the number of herds exhibiting symptoms is relatively small.”
New outbreaks have been confirmed in Michigan, adding to the 29 dairy herds affected in eight widely dispersed states, from Idaho to North Carolina. Texas has the largest number of infected herds at 11, followed by New Mexico with six and Michigan with five.
HPAI is a lethal disease among birds; the virus can wipe out a flock quickly. Animal health officials quarantine poultry farms when there is an outbreak and kill all the birds to stop the spread of the disease.
According to veterinarians and experts in the field, HPAI doesn’t affect dairy cows the same way as it does poultry. With proper veterinary care, cows can recover.
In dairy cows, HPAI causes a reduction in appetite and in milk production, most often among older cows. The infected cattle recover within a couple of weeks.
Authorities say HPAI is spread by wild birds, with an elevated risk during migratory seasons. The virus can be spread directly by birds through their secretions and droppings or indirectly through equipment, feed, or clothing that has been exposed to the virus. Farmers are encouraged to use good biosecurity practices, which include limiting access by outsiders to their barns.