Approximately 1500 pathogenic organisms exist on the planet (that we know of), of which a majority (75%) are transmissible from animals to humans (or visa versa).  Some of historic significance include bubonic plague, rabies, and brucella (Ranchers, officials uneasy about brucellosis).

There are other infectious diseases that are not shared between species, but are extremely infectious intra-species, such as classical swine fever (a.k.a. hog cholera), canine distemper, and equine infectious anemia.

For more than a century, states have enacted laws to protect animal purchasers from harm resulting from buying an animal infected with a contagious disease at the time of the sale, at least when the seller knew, or should have known, of the infection.  With our increasingly global environment, and the risk of infection through animals, vectors and other sources, has increased exponentially.  One need only read today’s headlines about the most recent scare about avian influenza (Chinese lab reveals H7N9 source; china-avian-flu), to begin to question what each individual’s legal exposure could be.

Most cases have historically involved the sale of livestock infected with contagious diseases.  In those cases, the seller was often accused of knowingly selling infected livestock.  More recently, there is growing   concern among livestock owners, because routine practices are serving as the basis for lawsuits.  The accused conduct, in the two following cases has not before been known to incur the risk of litigation.

In Indiana, the the Wilhoite Family Farm, LLC sued TDM Farms, Inc. (TDM v.Wilhoite) after Wilhoite’s hogs allegedly became infected with a virus that the TDM farm used to intentionally infect their own herd-a routinely used vaccination technique when the particular strain of a virus or bacteria is not available in a commercially available vaccine.

(The disease TDM farm was attempting to control is a highly contagious disease called Porcine Reproductive and Respiratory Syndrome  (PRRS the disease, its diagnosis, prevention and control), which causes widespread illness to swine and economic hardship to the farmers whose herds are infected.)  Hogs on the Wilhoite farm, located within one mile of the TDM farm, became infected with the PRRS virus shortly after TDM vaccinated their herd.  The viruses on both farms are allegedly genetically similar strains.  The legal claims against TDM for nuisance, negligence and trespass were upheld by the Court of Appeals of Indiana, finding that the claims were not preempted by the federal regulations governing the use of vaccines in animals (Virus-Serum Toxin Act) or barred by Indiana’s Right to Farm Act.  Farmers using this common method of vaccinating livestock must now consider whether that practice will expose them to similar litigation. (PRRS Lawsuit Could Affect Practices)

In another lawsuit involving horses, this one in New Jersey (NJ Thoroughbred Assoc v. The Alpen House) Plaintiff’s, including the New Jersey Thoroughbred Horseman’s Association, Inc., among others, sued Alpen House U.L.C., a corporation that owns and races thoroughbred horses at racetracks throughout North American, for strict liability and negligence for allegedly infecting horses at a racetrack in New Jersey with Equine Herpes Virus-Type 1 (“EHV”).  An emerging strain of this common equine virus causes Equine Herpes Virus Myeloencephalopathy (“EHM”), which renders affected horses neurologically impaired, often causing death or resulting in euthanasia.  Since it’s first known appearance, in addition to illness and death, EHM has resulted in lengthy quarantines of horse farms, horse shows and race tracks.  USDA and other organizations have issued numerous guidelines to help prevent the spread of this disease, for which a vaccine is currently unavailable. ( Equine Herpes Virus Myeloencephalopathy)

In a nutshell, this lawsuit is about the economic harm to certain race horse owners resulting from the State quarantine issued after the disease was diagnosed in New Jersey.  Of concern to horse owners is the latent period wherein the infection, while present, has not resulted in clinical signs of disease that would alert anyone that the horse was infectious.

These cases illustrate some of the potential legal liability for those involved in livestock enterprises.  More to come on the consequences related to cats and dogs.