Foot and Mouth Disease is caused by a picorna virus. It was last seen in the United States in the 1920s, when it was eradicated after an aggressive program of slaughter similar to what is occurring now in Europe. The virus affects many species of mammal: pigs, cattle, small ruminants, hedgehogs, elephants, etc, including most ungulates (cloven-hoofed animals). Llamas and alpacas fit into this last category. They appear to be susceptible to infection, although they appear to be fairly resistant to developing diseases.

The signs of Foot and Mouth Disease relate to the virus’ effects on the lining of the mouth, the tissue that produces the hoof, and occasionally other internal or external surfaces. Irritation of these areas leads to salivation, decreased feed intake, and lameness, and also allows for bacterial infection of those areas. On rare occasions, the virus is so aggressive as to cause death on its own. Most animals survive the infection, but with production animals like dairy cattle and swine, the loss in productivity during the period of illness and recovery is considered unacceptable.

Llamas and alpacas appear to be very resistant to developing clinical signs after infection. This may relate to their not being a natural host for the virus, but also probably relates to the structure of their foot: the horn of the
toe is not weight-bearing, thus lesions in that area only cause mild lameness. Camels were also thought to be relatively resistant, but some camel deaths have been reported in this most recent outbreak.

The reason there is so much uproar about this virus is because of its contagiousness. It is shed in all body secretions from infected animals and is present in all their tissues. Even processed goods like leather, canned meat, and cheese can contain enough virus to infect animals: the outbreak in England is thought to have come from canned meat left in restaurant scraps and feed to pigs. A person can spread the disease after talking to another person who was in contact with infected animals, simply by the virus moving from nose to nose. Recovered or vaccinated animals can still spread the virus for months, even when they appear healthy. Llamas and alpacas are significant in this current outbreak, not because they become particularly sick, but because they may harbor the virus for a period of time (experimentally no longer than 2 weeks) and later pass it on to other hoof stock.

Because of this contagiousness, our strategy to prevent losses has been to keep Foot and Mouth Disease out of the country. This strategy is the major reason that llamas and alpacas have to spend so much time in quarantine and have so many blood tests before coming into the U.S: any animal with antibodies against Foot and Mouth Disease is banned from entering the country. It is also one of the major reasons they discourage you from taking food across the border. Obviously, the movement of live animals is easier to regulate than the movement of canned hams or people, so the biggest risk to this country comes from importation of animal products, not animals, or that someone is careless.

We have opted not to vaccinate our animals for much the same reason that we stopped vaccinating people for smallpox: we could use antibody titers for surveillance (no animal in the U.S. should have antibodies to foot-and-mouth disease) and see the first signs of illness at the beginning of a possible outbreak. If we vaccinated (which is currently illegal) the disease might become more widespread before we realized it was here. Unless we vaccinated every susceptible animal (impossible because of wild animals like deer), we could expect long-term and repeated outbreaks of infection. To eventually eradicate the infection, we would have to result to the same draconian measures occurring in England right now, only on a much wider scale.

So what should we do? There’s not much we can do at the national level, except to postpone any trips to the English countryside, to be a little more understanding of import restrictions, and to avoid smuggling animal products past the customs officers. At the local level, we have to maintain our calm and use common sense. The llama and alpaca groups in this country have been blessed for many years with a relatively disease-free population. We had a bit of a scare two years ago with some infectious diarrhea outbreaks and will soon have
to come to grips with what the equine show people have known for years (or I learn every time I get on an airplane): every time you move an animal and expose it to a strange group, diseases are likely to be exchanged. We do not vaccinate against most of these diseases, because we do not have effective vaccines or we do not know what the diseases are. Making sure your animals are healthy before they travel, not exposing young, old, ill, or pregnant animals to outsiders, keeping show animals separate from the rest of the herd for a quarantine period,
and using chemical disinfectants on all implements will help reduce risk of a herd problem. Use caution about where you go and where you take your animals. The diseases have always been out there; it just takes a little carelessness to spread them around

Reproduced from www.orst.edu with permission of Susan Tornquist. Copyright © Oregon State University