Animal diseases keep this vet up at night

By Jan Shepel, Wisconsin State Farmer

MADISON - Not everyone lies awake at night thinking about foreign animal diseases, but those sleepless nights go with the territory for Dr. Paul McGraw, Wisconsin's State Veterinarian.

The number of international travelers surpassed 1 billion this year, says state Agriculture, Trade and Consumer Protection Secretary Ben Brancel, which contributes to the possibility that these so-called "foreign animal diseases" could be spread to the U.S. livestock population and to Wisconsin's critically important livestock sector.

There were a few scares in Wisconsin over the past year - McGraw's first as state veterinarian. Some came to light as the result of routine surveillance.

That's what happened in late June when two serum samples came up positive for H5 avian influenza, what some people call bird flu. Both H5 and H7 are "reportable diseases" in commercial birds and the first was potentially discovered on a Jefferson County game bird farm where the birds are raised outdoors.

The discovery triggered an incident management plan which the agency has trained for McGraw said, and the flock was quarantined. Investigators didn't find any sick or dead birds on the farm and further tests were negative for the virus that causes the disease.

As part of the joint state-federal investigation, bilateral trading partners were notified, which included Russia and Japan. Both countries immediately placed a ban on accepting any chicken from Wisconsin or any poultry products that came through the state, McGraw said.

It had an economic impact for a Campbell's Soup facility in Milwaukee which uses chicken from Georgia and the Carolinas. Any product made in that plant was prohibited from export to Russia or Japan, even though it contained no Wisconsin poultry products.

Investigators worked closely with county emergency managers and the state's poultry industry. The work helped area flock owners increase their biosecurity measures.

The investigation turned up no other birds that had the blood serum for this bird flu and investigators assume that the initial hit on the serum test came from contact with a wild bird that had the disease.

The trade restrictions with Russia and Japan were lifted 90 days after the investigation showed there was really no bird flu in the index flock or in the area, he said, and it isn't known exactly what the economic impact of the trade embargo was.

PED in hogs

The next disease of the summer facing the Animal Health Division was Porcine Endemic Diarrhea (PED) virus, which causes severe and acute bouts of diarrhea and rapidly spreads to pigs of all ages. McGraw explains that it is a disease that only affects pigs but its symptoms are identical to transmissible gastroenteritis (TGE.)

Though it is not a foreign animal disease, PED carries with it a devastating morbidity rate as high as 100 percent to a herd that hasn't been exposed to it. Mortality with a PED outbreak is variable, but could also be as high as 100 percent with young pigs, he added.

This disease will be very costly to the industry, McGraw said. China and Europe have had this disease for decades, but it hasn't been here before.

"This is kind of an eye opener. It got here through a corridor and we presume that corridor is still open."

That corridor could lead to countries that also have foot and mouth disease (FMD) and classical swine fever. "This is what keeps state veterinarians up at night," he said.

The hog industry is known for its strict biosecurity measures, with many hog barns requiring anyone entering them to shower and change clothing before coming inside. Animal health officials advised truckers to determine before their arrival where the line of separation should be between themselves and the production facility.

To stop the spread of this disease, McGraw said they were advising truckers and hog barn managers to not share equipment or personnel.

Using the DNA of the virus, it has been traced right to a province in China, he said. The disease was first detected in an Iowa herd in May and the U.S. Department of Agriculture is trying to figure out how it might have gotten here.

Animal health officials have been working hard to convince truckers that it's important to do the right things to stop the spread of this virus. That includes general truck washing protocols including removal of all manure and bedding and washing/disinfecting of the truck and trailer.

TB-exposed cattle

That wasn't the only challenge facing animal health officials in the summer. On July 17, the Minnesota Board of Health informed DATCP that there were cattle in Wisconsin that had been exposed to tuberculosis.

They had originated from Michigan's recent TB-positive herd, had failed to meet import requirements and had potentially exposed other cattle in Wisconsin.

McGraw said that by the time Wisconsin investigators found out about the cattle passing through the state they had already gone on to Minnesota. "Nobody did anything intentionally wrong but there could have been consequences."

Michigan has a bigger headache, he said, with thousands of feeder cattle that have been exposed to the positive cattle.

Testing in Wisconsin did not turn up any TB-positive animals.

The year in animal health was rounded out by a farm-raised deer that tested positive for chronic wasting disease (CWD).

"The (captive deer) industry has been doing a tremendous job," McGraw said. There have been a total of about 37,500 animals tested from Wisconsin farms for the disease and this is the first positive since 2008.

This positive animal came from a hunting preserve in Marathon County which has been doing everything possible to comply with state regulations. Their breeding farms are double fenced to keep potentially infected wild deer out and over 1,000 deer have tested negative for the disease since 2001 from their operation.

The agency is now looking at the "age cohorts" of the positive animal to see if there could be more of the neurological disease on the hunting preserve. It could also be that the disease spontaneously sprang up in this particular deer, he said.

Animal health official know much more about the disease than they did 10 years ago, but there are still some mysteries, he said.