Investigators find no threat in Washington cattle deaths
“During this investigation, we have found no threat to the health of people or other animals,” said Washington State Veterinarian Leonard Eldridge. “We have not been able to identify a common cause of death of these animals. Frankly, we may never know specifically what killed the animals that died before the start of this investigation.” When Washington State Department of Agriculture (WSDA) veterinarians visited the farm on March 8, they immediately established that the death of the animals had occurred over several months. The dairy’s owner reported to investigators that between 50 and 60 cows had died. During this first visit to the farm, investigators found no symptoms of contagious foreign animal disease in any living animals.
At that time, the farmer reported concerns about heavy metals contamination of the animals’ feed source as a possible cause of death. Due to these concerns, the dairy owner made a decision not to ship milk off the farm since December 2006.
The animals were eating alfalfa hay, as well as haylage, grown in Addy in Stevens County. Investigators took feed samples at the farm and at the site where the hay was grown. The feed samples were tested for heavy metals and a nutritional analysis was conducted.
The heavy metals testing on the feed was conducted by the Washington Animal Disease Diagnostic Laboratory (WADDL) in Pullman, WA. The laboratory has determined that no elements analyzed were present at excessive concentrations in comparison to recognized reference ranges. In other words, WADDL investigators have determined that the feed is safe to give to cattle.
Nutritional testing on the feed was conducted at WSDA’s laboratory in Yakima, WA. The hay samples would have provided appropriate nutrition for adult cows that are not being milked. Milking cows generally require a feed supplement that provides additional vitamins, minerals and calories to ensure proper nutrition. On March 21, WSDA investigators returned to the farm. The herd owners volunteered three animals to be sacrificed to aid in the investigation. The animals were autopsied at WADDL where further pathology, microbiology and toxicology analyses were conducted. Again, the lab investigators found no remarkable concentrations of any of the heavy metals included in their analysis. The liver, kidney, blood, hair and hoof samples did not appear to contain excessive concentrations of any of the elements tested. Furthermore, other tests found no presence of foreign animal disease, bovine spongiform encephalopathy or any other potentially fatal diseases.
WSDA’s Eldridge has advised the herd owners of the results of the investigation. Eldridge suggested that the owners take steps to improve the general sanitary conditions on the farm and seek consultation on herd health management and nutrition. Eldridge also advised that a veterinarian should immediately examine any additional dead animals.