- Importation (legal and illegal) of infected or exposed animal(s) or an animal carrying a disease vector such as a tick. These may be livestock, companion animals, wildlife, or zoological animals. Importation of embryos and semen also may provide a pathway for FAD entry.
- Immigrants and foreign visitors (legal and illegal) to the United States (U.S.) may bring the agent or pest into the country. Foreign travelers may transport a disease-causing agent on their bodies, clothes, and/or possessions.
- Migratory birds or insects may serve as biological vectors that transport an FAD into the country. One example illustrating this pathway is heartwater. Heartwater is an acute tickborne disease of domestic and wild ruminants caused by the rickettsial bacterium Cowdria ruminantium, which is transmitted by Amblyomma ticks. Should this disease enter the U.S., mortality rates in ruminants might range from 40 – 100 percent. Risk of heartwater introduction to the U.S. has increased because the tropical bont tick has been introduced from Africa to the Caribbean through the importation of infested cattle. The tick has now spread, possibly by the movement of migratory birds, among the islands. There is a potential for migrating birds, specifically the cattle egret, to transmit this devastating condition to the U.S.
- The importation of vaccines, reagents, tissue cultures, and germplasm through legal (low risk) and illegal (high risk) routes potentially may bring a FAD into the U.S.
- Bioterrorism, which is terrorism involving the intentional release or dissemination of biological agents, which can include bacteria, viruses, and toxins, that could not only harm humans, but also drastically impact California’s livestock industry.
- Intensive farming practices that result in high animal density on individual farms and increased animal contact; increased stocking density may contribute to increased stress and decreased disease resistance; and, the intensive rearing of poultry and swine has enabled these industries to be leaders in the development of effective biosecurity strategies.
- Geographical distribution of livestock facilities in close proximity may result in increased contact between facilities. The density of swine in SW Taiwan is 6,500 hogs/square mile, and it is believed that this high density contributed to rapid movement of foot and mouth disease in 1997. To illustrate, on March 20, 1997, 70 farms were infected and within 8 days 1,175 farms were infected. During the outbreak, foot and mouth disease was infecting farms at a rate of 200-300/day.
- As the rural/urban interface narrows, livestock and poultry facilities are in closer contact with urban populations. Animals or agricultural workers may then be at increased risk of exposure to illegal, contaminated animal products or to visitors from foreign countries where FADs are present.
- Out sourcing of farm related activities (feed production, rearing of replacement animals off premises, processing crews, hoof trimmers, animal health, and nutritional consultants, etc.) also may increase indirect contact between livestock facilities.
- International marketing within the global economy results in increased international movement of livestock.
- Marketing patterns may lead to increased inter- and intra-state movements of livestock.
- Sudden, unexplained death loss in the herd or flock;
- Severe illness affecting a high percentage of the animals;
- Blistering (erosions, ulcers) around an animal’s mouth, nose, teats, or hooves;
- Unusual ticks or maggots; and
- Staggering, falling or central nervous system disorders.
Animal Disease Emergency Management Program
The prevention, detection, immediate containment, and eradication of emergency animal diseases are high priorities. Some animal diseases have human health implications, and all affect production and marketability of livestock and poultry; therefore, these functions contribute to a solid foundation for economic prosperity while decreasing human health risks for the people of California. Activities to achieve these goals include outreach and educational services, performing routine disease surveillance, and disease investigations to detect the introduction and spread of injurious animal pests and diseases, and, when necessary, the implementation of animal quarantine to control the spread of disease.
Foreign and Domestic Animal Diseases
Emergency animal diseases may be foreign animal diseases or domestic diseases. Foreign animal diseases (FAD) are serious diseases that have either been eradicated from, or have never occurred in, the United States (U.S.).
To date, 13 serious livestock and poultry diseases have been eradicated from the U.S. through the cooperation of federal and state animal health officials, private veterinarians, livestock producers, and animal industries. Many others have never been seen in the U.S. The following animal diseases have been eradicated from the U.S.: Contagious bovine pleuropneumonia (1892), Foot and Mouth disease (1929), fowl plague (1929), glanders (1934), dourine (1942), Texas cattle fever (1943), vesicular exanthema (1959), screwworm (1982), Venezuelan equine encephalitis (1971), sheep scabies (1973), hog cholera (1978), and exotic Newcastle disease (2003).
The goal of disease prevention is to minimize the risk that foreign animal diseases will enter the U.S., and if they do, to quickly recognize the threat and effectively manage it.
The Animal Health Branch monitors vessel and aircraft garbage entering from foreign countries. Did you know that all international garbage, even leftovers from that gourmet meal served on the flight from Paris, is cooked to 212°F for two (2) hours before being disposed of in a landfill? If the garbage were not heated, it could potentially transmit a bacteria or virus that could spread through the livestock industry. Even a garbage container on board an international ship must be covered as the ship comes within 12 miles of a U.S. coastline. This prevents a seagull from grabbing the garbage and carrying it to land, perhaps to a farm, where it can potentially spread disease.
Also, the interstate animal movement into California is closely monitored through movement permits and health certificates. This allows the Branch to trace animal movements during a disease outbreak to identify the potential sources.
The Foreign Animal Disease Threat
There are many pathways of animal disease introduction and state and federal governments have programs in place to decrease the risk. However, no prevention plan is failsafe.
The lines of defens must include everyone involved with animal agriculture – veterinarians, livestock producers, horse owners, and also veterinarians with small animal or exotic animal practices, zoologic park personnel, companion animal owners, and Americans who enjoy international travel. If a serious animal disease enters our country there would be many ways for the rapid spread of disease throughout our animal populations. Only through prompt recognition and quick containment can we prevent disease from spreading out of control!
Pathways of Animal Disease Introduction
The nation is at risk of foreign animal disease (FAD) entry through many pathways:
Spread of Disease
Risk factors for the rapid spread of disease after introduction into a susceptible population include:
In addition to FAD concerns, certain domestic animal disease outbreaks are considered emergencies due to the severe negative impact on the health and welfare of livestock, and on the interference of trade of animals and animal products. The Emergency Disease Program strives to prevent and control outbreaks of domestic animal disease.
Lines of Defense
The United States Department of Agriculture and the California Department of Food and Agriculture, Animal Health Branch have programs to safeguard the U.S. international and California state borders, respectively, from the incursion of FADs. However, no protection is failsafe, and each citizen must do their part to protect animal agriculture from disease threats.
Private practitioners and producers play a critical role in disease reporting when they notify state or federal animal health officials of suspicious foreign animal diseases or unusual cases. Veterinarians and producers should rely on their judgment and experience in reporting potential foreign animal disease occurrences, and keep in mind that it is “better to be safe than sorry”.
Immediate response to suspect foreign animal diseases is crucial in stopping a disease outbreak or pest infestation.
Examples of suspicious signs of foreign animal diseases:
Producers should notify their veterinarian if they see suspicious signs in their herd or flock.
Monitoring Animal Disease
Laboratory personnel and practicing veterinarians are required by law to report suspected FADs and certain severe domestic diseases. Producers are encouraged to be aware of the potential signs of FADs and to call their veterinarians when animals under their care experience show suspect signs. Early notification allows for prompt control, containment, and, when possible, eradication. The California Reportable Diseases of Animals and Poultry specifies the diseases to report and the timeframe and method for reporting.
The Animal Health Branch has voluntarily participated in the National Animal Health Reporting System (NAHRS) since March 1998. The NAHRS is a passive system for reporting information on the confirmed presence of diseases notifiable to Office International des Epizooties (OIE). The state veterinarians office is responsible for receiving, validating, and ensuring the quality of data reported for their state. The Centers for Epidemiology and Animal Health serves as a national collection and dissemination center.
Animal disease monitoring is not just a national priority, but an international one! Office International des Epizooties (OIE) was founded in 1924 with three main objectives: to provide information on animal health worldwide; to coordinate research on, and control of, important animal diseases; and to harmonize trade regulations involving animals and animal products. The US became a member in 1975 with representatives from the United States Department of Agriculture-Animal and Plant Health Inspection Service (USDA-APHIS), Agricultural Research Service, Food and Drug Administration, National Biologic Service, and academic institutions participating in specialist commissions and working groups. Each state is required to immediately report List A transmissible diseases of animals to the USDA-APHIS which in turn reports to the OIE.
Animal industry Quality Assurance Programs are excellent sources of information about the care and handling of livestock. Quality Assurance Programs exist for pork, beef, dairy, poultry, and sheep industry groups. Some Quality Assurance Programs are unique to California, while others are nationwide programs. The University of California Veterinary Extension and Animal Science Extension are also valuable sources for animal-related information.
Informational publications covering a range of issues are available for download. If you have a submission for a newsletter or an issue you would like addressed, you may either read the issues at this website or sign up to receive mailings by contacting us.