By ANN HINCH
INDIANAPOLIS, Ind. — With bovine tuberculosis and avian influenza in the national news, and both kinds of cases in Indiana in 2016, the state’s Board of Animal Health (BOAH) is staying vigilant of a potential porcine disease.
Seneca Valley virus, or SVV, was in the news in the last couple of years but hasn’t appeared to be as much in 2017. State Veterinarian Dr. Bret Marsh made this observation at BOAH’s April 11 quarterly meeting, adding this doesn’t mean it’s not still around. On the contrary, he said, the Upper Midwest has had a preponderance of SVV cases found at pork processing plants.
While Indiana itself has a number of such plants, he said there don’t appear to be cases of SVV so far, while at the same time, there are almost daily reports of clinical symptoms in pigs at Wisconsin plants. Minnesota and Michigan also have problems, he said.
There are limited data on SVV, according to the Swine Health Information Center (SHC) of Ames, Iowa, but it doesn’t appear to be fatal in many cases. The chief problem with SVV is that symptoms like lesions observed on infected pigs “cannot be distinguished clinically” from those caused by foot-and-mouth disease (FMD), which can have a high mortality rate in young pigs, according to Iowa State University information.
The ideal would be to find out how SVV spreads and prevent it, but that’s proving difficult. It was first identified 15 years ago, but the SHC reported experiments haven’t found enough consistency of infection or clinical symptoms in infected animals to be able to say “this is how it happens.”
Marsh said telltale lesions appear to develop quickly, to the point where a pig might not show clinical signs of infection on the farm, but develop them in transit to a processing or holding facility.
“We have a lot of hogs shipped in our state,” he noted, adding this is the best reason to stay alert to signs of SVV and, if symptoms appear, to be certain that’s what it is and not confuse SVV with FMD.
Poultry, beef infections
BOAH continues to be alert, as well, to reports of avian illness coming from nearby states, especially in light of dealing with its own January 2016 situation involving infected turkey flocks in southern Indiana. In early March, two commercial flocks of chickens in Lincoln County, Tenn., were found to be infected withhigh-pathogenic avian influenza (HPAI); since then, other flocks in Tennessee, Alabama, Kentucky and Wisconsin have tested positive for low-pathogenic (LPAI) strains.
Tennessee State Veterinarian Dr. Charles Hatcher explained the difference between HPAI and LPAI is mortality rate. The former is often fatal, while LPAI may not even show up in symptoms in infected birds – the problem is a slight change in viral structure can occur in LPAI, turning it into an HPAI strain.
Dr. Michael Kopp, who specializes in commercial poultry for BOAH, said for that reason, LPAI flocks are euthanized and disposed of similarly to HPAI birds.
“What are you going to do with these flocks?” he asked, referring to the fact other states and even countries will impose temporary bans on poultry products from areas of infection despite the food products not posing a danger to human health. “The processing companies don’t want them. You aren’t going to move them (i.e., sell or transfer) down the road.”
He gave a brief report to the board about the incidence of infections worldwide, mostly in Europe and Asia and mostly wild birds, so far this year. “Let’s hope now we’re past it, and we won’t have any next year,” he added as others nodded in the room. Last week, Hatcher released the control zone around the two HPAI farms, as well as lifting the statewide poultry health advisory that had prohibited commingling of birds: “Poultry owners across Tennessee should continue to monitor their flocks and immediately report any spike in illness or death.”
Similarly, Kentucky’s state veterinarian released the surveillance zones surrounding two Christian County farms that tested positive for LPAI. Nearly 25,000 birds were depopulated and buried in that eradication effort.
Regarding the bovine TB situation in Franklin County, Dr. Kyle Shipman, heading BOAH field operations, reported that the farm identified with the infection in cattle a year ago has been cleared to restock its herd (a second positive farm was identified in December). The 10-mile surveillance area being tested in the county, and area along the White River corridor – which is thought to play a part in the spread of TB among cattle and deer – are still active and cover nearly 400 herds to be monitored.
The December-identified herd is presenting problems, he reported, because the owner is reluctant to depopulate cattle for prevention, unless any are shown strongly positive in testing for the disease. Marsh explained the owner’s father left her the cattle when he died and her mother is ill, so there is a strong sentimental attachment to the animals.
Shipman added while the owner has complied by letting BOAH testers on her property, she has not provided any help in rounding up the cattle or facilities necessary to complete this second round of testing. He wryly noted as the animals are Longhorns, they aren’t easy to capture and contain while avoiding human injury. Marsh said he is sympathetic to the herd owner’s feelings and BOAH is trying to work within her concerns.
But he also pointed out with cooperation from the April 2016 herd’s owner, BOAH was able to make a decision about what to do with the cattle and the potential for TB exposure to the area within five weeks, whereas the second farm is taking several months so far.
Updated swine, pets rules BOAH passed the final readings of two rules on April 11, as well. One repeals the herd management plan requirement for pork producers with a confirmed positive diagnosis of a swine enteric coronavirus disease, or SECD.
In 2014 BOAH imposed this requirement to comply with federal action, but since, the USDA has determined these plans were not providing information deemed useful to its SECD program.
The other rule concerns rabies vaccinations in cats, dogs and ferrets three months of age and older. It basically brings BOAH into compliance with updated rules under the National Assoc. of State Public Health Veterinarians Compendium of Animal Rabies Control and changes state rule language to reflect animals requiring annual boosters be re-vaccinated 12 months after their shot rather than within that 12-month window.
Sarah Simpson, who works in BOAH legal affairs, explained the rule also provides more guidance to local governments how to handle a situation if such an animal is exposed to rabies and is overdue for its booster vaccination. Along the same lines, it also reduces the state requirement for a six-month quarantine of such a pet to four months.