BE AWARE OF THE SIGNS OF FOREIGN ANIMAL DISEASE
If a foreign animal disease crosses into the United States, veterinarians and livestock producers will be the first line of defense.
The threat of foot-and-mouth disease (FMD) has loomed over U.S. livestock producers for decades. According to the U.S. Animal and Plant Health Inspection Service (APHIS), the United States eradicated FMD in 1929, but many countries around the world are still battling the disease.
FMD is highly contagious and can infect cattle, swine, sheep, goats, deer and other animals with divided hooves. While FMD is not a public health or food safety threat, it is a worldwide concern due to its quick-spreading nature and ability to cause widespread economic losses.
The signs of FMD include vesicles, which are similar to blisters, that quickly pop and cause erosions in the mouth or on the feet. Yet, vesicles often pop quickly, which makes them difficult to notice. Other signs of FMD include: increased body temperature for two to three days; sticky, foamy saliva and lameness.
However, Van Metre cautions that overt clinical disease may be subtle, particularly in small ruminants.
“If cattle are lame, check their mouth. If they are drooling, check their feet and teeth,” he advises. “That would suggest the presence of FMD. We have to remember the subtly of those lesions in sheep.”
In addition to subtle signs, FMD can easily be confused with other diseases, including vesicular stomatitis, bluetongue, bovine viral diarrhea, foot rot in cattle and swine vesicular disease.
“There can be significant overlap in terms of lesions in the mouth and on the muzzle with what might occur in foot-and-mouth disease,” Van Metre notes. “If an apparent contagious disease is spreading through a population that doesn’t fit well with any of the endemic infectious diseases of North America, the best bet is to contact state veterinarians or state animal health officials.”
Local veterinarians and livestock producers also should take digital photos, or even videos, of the animal to provide state officials with as much information as possible.
“I keep a list of state vets in my phone, and when I encounter a case – and I have encountered things that make me concerned about the possibility of foreign animal disease – I consulted with them,” Van Metre says. “I’ve found they are always willing to talk and be consulted. In fact, they far preferred to be consulted. You don’t have to make the clinical call, you just have to make the telephone call.”
If a farm is experiencing an unusual disease outbreak, Van Metre recommends DSRs minimize on-farm visits.
If a visit is necessary to deliver medication or supplies, DSRs should practice good biosecurity protocols to help limit spread of infection. This includes avoiding animal contact; minimizing vehicle traffic near animals; disinfecting tires upon exit; and using disposable footwear covers.
If possible, ask if the meeting can take place at a local coffee shop and not on the farm. Some operations have even established drop-off points with lockable sheds to limit the chance for disease transmission.
Good biosecurity protocols help minimize the spread of endemic disease and can also prepare the livestock industry for a foreign animal disease outbreak.
“The recent outbreak of PEDv (porcine epidemic diarrhea virus) really showed the swine industry where the cracks were in their biosecurity programs,” Van Metre notes. “Now, many farms have deliberately designed traffic patterns to mitigate the chance of delivery vehicles transmitting those disease agents from farm to farm.”
Be ready to call the state veterinarian. A complete list can be found through the American Veterinary Medical Association (AVMA).
Signs of FMD:1
- Great increase in body temperature for 2 to 3 days
- Vesicles that rupture and discharge clear or cloudy fluid, leaving raw, eroded areas surrounded by ragged fragments of loose tissue
- Sticky, foamy, stringy saliva
- Eating less because of painful tongue and mouth blisters
- Lameness with reluctance to move
- Low milk production in dairy cows
- Heart disease and death, especially in newborn animals
Other Key Foreign Animal Diseases:2
African Horse Sickness
African horse sickness (AHS) is a highly fatal, insect-borne viral disease of horses and mules. The clinical signs are characterized by an impairment of the respiratory and circulatory systems.
African Swine Fever
African swine fever (ASF) is a contagious tickborne systemic viral disease of swine characterized by fever, recumbency, epidermal cyanosis and visceral hemorrhages.
1 Food-and-mouth disease. APHIS Veterinary Services Factsheet. July 2013.
2 Texas A&M University College of Veterinary Medicine. Foreign Animal Diseases. Accessed April 11, 2018. Available at: http://www.cvm.tamu.edu/fadr.