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Animal diseases and prevention

Learn how to report and respond to avian influenza, equine botulism, and more

Preventing spread of diseases

Biosecurity refers to everything people do to keep diseases – and the viruses, bacteria, funguses, parasites, and other microorganisms that cause diseases – away from birds, livestock (cattle, swine, sheep, goats), property, and people. Biosecurity measures can include keeping visitors to a minimum, changing clothes before entering areas, cleaning tools or equipment before moving them to a new facility, and more.

Anyone involved with poultry or livestock production, from a small backyard to a large commercial producer, should review their biosecurity activities to ensure the health of their animals. USDA’s Animal and Plant Health Inspection Services (APHIS) has materials about biosecurity, including videos, checklists, and toolkits available online .

Types of Diseases

In general, there are four major categories of diseases that can affect livestock. Some are considered high-consequence, meaning they spread rapidly from animal to animal/herd to herd, and are expensive and difficult to eradicate. The response to high-consequence diseases involves various state and federal agencies in the efforts to control the further spread.


A disease that can be passed directly or indirectly between animals and humans. Domestic animals, wild animals and insect species are the common link as either the origin, a reservoir (animal or insect that carries an infectious agent but is not harmed by it) or vector (disease acquired from blood-feeding insects). Some examples of zoonotic diseases include rabies, anthrax, West Nile virus, Lyme disease and salmonellosis.

Reportable Diseases/Foreign Animal Diseases

A reportable animal disease is one that, by law, must be reported to state and/or federal animal or public health officials, typically by a livestock producer's veterinarian. Reportable means that the United States Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) has a control or eradication program in place for the disease. Reporting helps identify disease outbreaks, limits their spread, and minimizes the economic and health impacts on animals and people. These diseases are high risk with severe economic, animal health, and often public health consequences. Examples of reportable diseases include brucellosis, scrapie, bovine tuberculosis, pseudorabies, New World screwworm, and vesicular stomatitis.

Among reportable diseases are foreign animal diseases (FAD), also called transboundary animal diseases. These are also high-risk animal diseases that are not normally present in the United States or have been previously eradicated. Foot and mouth disease, highly pathogenic avian influenza, African swine fever, classical swine fever and virulent Newcastle disease are classified as "Tier 1" (highest risk level) foreign animal diseases by the USDA.

Endemic Diseases

Endemic is the constant presence and/or commonness of a disease or infectious agent in animals within a geographic area. Anthrax is endemic in limited areas of the western and midwestern United States, for example. Other levels of disease, such as epidemic, refer to an often sudden increase in the number of cases of a disease above what is normally expected in a population in a location. Outbreak carries the same definition as epidemic but is often used for a more limited geographic area. Sporadic refers to a disease that occurs infrequently and irregularly.

Emerging Diseases

A disease can be considered "emerging" if it is newly identified or previously unknown, causes disease, infection, or infestation in animals, and has the potential to result in significant animal or public health impacts. It might also be a previously known disease that has changed in some way, either by an increased ability to cause disease, an expanded host range, a change in geography, and/or causing unexpected sickness and death. West Nile virus, avian influenza, and porcine epidemic diarrhea virus are some examples of emerging diseases.

Reporting diseases

Contact our Veterinary Health Division to report concerning diseases.

Title 7 - §105. Requiring the Reporting of Contagious Diseases (Formerly §121)

A. All veterinarians practicing veterinary medicine in this state shall report any of the diseases listed in this Section to the state veterinarian within 24 hours after making a diagnosis or tentative diagnosis of any such disease. The report may be made by telephone, fax, or electronic mail. The reportable diseases are classical swine fever (hog cholera), anthrax, vesicular conditions, all equine encephalomyelitis conditions, transmissible spongiform encephalopathies (including chronic wasting disease, scrapie, bovine spongiform encephalopathy), pseudorabies (Aujeszky's disease), tuberculosis, Brucellosis, rabies, strangles (Streptococcus equi equi), equine herpes virus 1, equine viral arteritis, spring viremia of carp, viral hemorrhagic septicemia, Newcastle disease and other paramyxovirus infections, avian influenza (highly pathogenic), ornithosis (chlamydiosis, psittacosis), Salmonellas (pullorum disease or fowl typhoid), infectious laryngotracheitis (other than vaccine-induced), trichomoniasis, any disease classified by USDA as a foreign animal disease, or any other disease condition which may seriously threaten any animal population of this state.

B. Reports should include the:

  1. name, address, and phone number of the owner

  2. location of the premises

  3. morbidity and mortality rate at the time of reporting

  4. number of susceptible animals in the immediate area

  5. approximate number of animals or poultry exposed.

C. Reports of disease outbreaks will be coordinated by the state veterinarian.

D. Livestock owners who suspect the occurrence of contagious disease should immediately contact the local practicing veterinarian, area regulatory veterinarian or county agent who, in turn, will be responsible for reporting to the state veterinarian.

E. An investigation of the reported contagious disease will be made by representatives of the Livestock Sanitary Board, preferably with the veterinarian or county agent reporting the disease. If necessary to protect the animal and poultry populations, a quarantine may be imposed on involved and exposed animals and areas. The quarantine will remain in effect until the threat has been removed.


Contact info

Veterinary Health Division, Animal Health and Food Safety