BSE Suspect Cow Is Domestic And More Than 12 Years Old
In yesterday's special edition of BEEF Cow-Calf Weekly, I reported that a BSE-suspect animal that died as a result of calving complications last April was older than "12 months." That should have been 12 "years," which places the animal's birth year well before when the U.S. enacted its ruminant-to-ruminant feed ban in 1997. While the supporting text of the article should have made it obvious the suspect animal had to be much older than 12 months, I apologize for any confusion the oversight may have caused.
The carcass of the domestic animal was destroyed and its brain stem was collected for testing by a private-practice veterinarian in a remote location. That practitioner preserved the brain tissue in formalin as was allowed at that time. Testing protocols, which were changed in June, now disallow preservatives and freezing of such tissue.
The preservative prevents use of both a BioRad rapid screening test and a confirmatory test, known as the Western blot test. This leaves only one type of test, the gold-standard immunohistochemistry (IHC) test.
Unfortunately, however, after preserving the sample, USDA says the practitioner forgot to forward it to the agency for testing until last week. It arrived at the National Veterinary Services Lab (NVSL) in Ames, IA, on July 19.
Subsequent testing at NVSL with the IHC test found a positive result but was ruled as "non-definitive" due to an abnormal staining distribution of the prion proteins. Thus, the animal's brain tissue samples were to undergo further testing at NVSL and at the International Reference Laboratory in Weybridge, England. Results are expected next week.
During yesterday's press conference, USDA Chief Veterinarian John Clifford stressed that the animal's carcass was incinerated and no part of the animal made it into either the human food or animal feed chain.
In yesterday's special edition of BEEF Cow-Calf Weekly, I reported that a BSE-suspect animal that died as a result of calving complications last April was older than "12 months." That should have been 12 "years," which places the animal's birth year well before when the U.S. enacted its ruminant-to-ruminant feed ban in 1997. While the supporting text of the article should have made it obvious the suspect animal had to be much older than 12 months, I apologize for any confusion the oversight may have caused.
The carcass of the domestic animal was destroyed and its brain stem was collected for testing by a private-practice veterinarian in a remote location. That practitioner preserved the brain tissue in formalin as was allowed at that time. Testing protocols, which were changed in June, now disallow preservatives and freezing of such tissue.
The preservative prevents use of both a BioRad rapid screening test and a confirmatory test, known as the Western blot test. This leaves only one type of test, the gold-standard immunohistochemistry (IHC) test.
Unfortunately, however, after preserving the sample, USDA says the practitioner forgot to forward it to the agency for testing until last week. It arrived at the National Veterinary Services Lab (NVSL) in Ames, IA, on July 19.
Subsequent testing at NVSL with the IHC test found a positive result but was ruled as "non-definitive" due to an abnormal staining distribution of the prion proteins. Thus, the animal's brain tissue samples were to undergo further testing at NVSL and at the International Reference Laboratory in Weybridge, England. Results are expected next week.
During yesterday's press conference, USDA Chief Veterinarian John Clifford stressed that the animal's carcass was incinerated and no part of the animal made it into either the human food or animal feed chain.