Vet's Perspective

Opinion
Mar 1, 2013
by WLJ

Foot and mouth disease

Foot and mouth disease (FMD) is a highly contagious and severe disease that affects cloven-hoofed animals, such as cattle, swine, sheep, goats and deer. The virus that causes this disease has been eradicated from the U.S., but in recent years has again been appearing in the news. FMD spreads rapidly among herds and causes ulcer lesions most often in the mouth, on the teats, and inter-digitally between the hooves. Although many animals may recover from fever and associated lesions, the cost of treatment and loss of milk and meat products is very detrimental overall.

Disease may be spread directly through animal contact, as well as carriers such as farm employees and equipment that have been exposed to sick animals. Affected animals may be noted to have excessive salivation caused by painful ulcers and vesicles in the mouth. These blisters easily and frequently rupture, potentiating the spread of illness.

Any evidence of these types of lesions is cause for concern, and must be reported to your veterinarian and state health officials.

Control of disease entry into unaffected regions, such as North America, is critical. Disease is currently reported in over 100 countries worldwide; the last outbreak to occur in the U.S. was in 1929. Due to the lack of disease present in our region, animals are particularly susceptible to illness if an outbreak were to occur. Animals and byproducts from affected animals are denied entry into FMD-free zones.

One of the many challenges for livestock and horse owners is the constant control of introduction and spread of disease on a farm. USDA defines biosecurity as: “doing everything you can to reduce the chances of an infectious disease being carried onto your farm by people, animals, equipment, or vehicles; either accidentally or on purpose.” Although risk of disease is inevitable, there are many things that producers can do in order to reduce pathogen exposure.

The first key to management is recognizing the difference between “infectious” and “contagious” diseases. A pathogen that is considered infectious may cause disease in any animal within a herd and be transferred by insects, animal secretions or discharges, and equipment and machinery for everyday use on the farm; however, the illness may or may not result in an outbreak of disease among all animals. A contagious disease poses more of a risk because the transmission is mainly through direct contact between animals. Although often inconvenient, it is the best practice to keep new animals to a herd separated for at least two weeks; this allows one to observe the new addition for signs of disease and reduce exposure.

The continuous movement of animals today, whether it is for shows, leisure, or sale, allows exposure between animals and thus transmission of disease. A good practice to aid prevention of illness is to keep your herd vaccinated routinely and maintain a good nutritional plan for all ages of livestock. Your veterinarian and nutritionist can help your  farm with a plan to fit your needs. Reducing contact between farms via a “buffer zone” can be helpful in some instances. One can decrease the contact between animals by housing livestock in groups or pens that do not allow nose-to-nose contact, as well as providing double fence lines between susceptible animals.

Routinely disinfecting your equipment and feed and water pans with bleach can help prevent the buildup of dirt and manure that attract pathogens of all sorts. When traveling, make it a practice to use your own equipment and not share between farms. Finally, evaluate your water source and food storage components of management. Several infectious agents are spread within fecal matter. Proper rodent and other pest control is necessary in order to prevent urine and fecal contamination of your farm’s food and water supply.

For further information on biosecurity measures, please contact your local veterinarian, or visit USDA online at www.usda.gov.

Recently, an FMD vaccine was developed by federal researchers and was approved for manufacture and administration in the U.S. if an outbreak were to occur. The adenovirus vaccine does not contain live virus and is said to induce immunity in cattle and pigs within seven days of administration. The rapid immune response is desired so as to significantly reduce the rapid spread of disease. USDA has noted that the adenovirus vaccine offers protection for at least 42 days; further studies are still in progress in order to extend coverage (minimally six months) to that of an inactivated type of vaccine regimen. Because there are several serotypes of the virus (at least seven), each type requires a separate vaccine; researchers are working to create a more inclusive vaccine that will provide a broader immune response. — Dr. Genevieve Grammer is a veterinarian working out of the Pikes Peak region. Please direct correspondence to drgigi19@gmail.com.

 

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