The U.S. Department of Agriculture (USDA) has confirmed an atypical case of Bovine Spongiform Encephalopathy (BSE) in an approximately five-year-old or old beef cow at a slaughter plant in South Carolina. BSE is a neurologic disease affecting cattle, commonly known as mad cow disease.

The USDA assures the public that this animal never entered the slaughter channels and posed no risk to the food supply or human health in the United States. As a result, no trade impacts are expected because of this finding.

The confirmation of this case was made by the USDA Animal and Plant Health Inspection Service’s (APHIS) National Veterinary Services Laboratories (NVSL). The cow in question was tested as part of APHIS’s routine surveillance of cattle that are considered unsuitable for slaughter. The radio frequency identification tag associated with the animal traces back to a herd in Tennessee. Authorities in South Carolina and Tennessee, along with APHIS, are actively collecting more information as part of an ongoing investigation.

Atypical BSE is known to occur sporadically in older cattle and is considered a rare phenomenon across all cattle populations. This marks the seventh detection of BSE in the United States, with the previous six cases being atypical BSE, except for the initial case in 2003, which was a classical BSE found in a cow imported from Canada.

The World Organization for Animal Health (WOAH) recognizes the United States as having a negligible risk for BSE. According to WOAH guidelines, atypical BSE cases do not impact a country’s official BSE risk status recognition, as this form of the disease is believed to occur spontaneously at a very low rate in all cattle populations. Therefore, the negligible risk status of the United States remains unaffected by this atypical case.

The United States maintains a robust system of safeguards against BSE, safeguarding both public and animal health. These measures include the removal of specified risk materials, which are parts of an animal that could potentially contain BSE, from all animals presented for slaughter. Another critical safeguard is a strict feed ban designed to protect cattle from the disease. Additionally, the USDA’s ongoing BSE surveillance program plays a vital role in detecting the disease at low levels within the U.S. cattle population, as exemplified by this recent detection.

about BSE
Bovine Spongiform Encephalopathy, commonly known as mad cow disease, is a progressive neurological disease affecting cattle. It is caused by prions, infectious agents composed of protein material, which impact the brain structure of infected animals, leading to a loss of motor skills and eventual death. Clinical signs of the disease include behavioral changes, coordination problems, weight loss, and decreased milk production. Unfortunately, there is currently no treatment or vaccine available to prevent BSE. The disease can manifest in two forms: classical and atypical, with neither form being contagious.

Classical BSE is primarily transmitted through the ingestion of certain materials, such as the brain and spine, from infected animals. The main route of transmission was previously through contaminated animal feed containing meat or bone meal from infected cattle. However, strict regulations, including the removal of ruminant protein from feed for ruminants and the prohibition of certain high-risk cattle tissues in feed for all animals, have effectively prevented classical BSE infections. The incubation period for classical BSE is approximately 3 to 6 years from the time of infection until the onset of clinical signs.

Atypical BSE, on the other hand, occurs spontaneously and rarely in older cattle, without any association with contaminated feed or infected materials.