This communication is a very preliminary discussion about the relevance of concerns regarding transmissible spongiform encephalopathy (TSE) in alpacas and llamas.

TSE's are the prion particle diseases of animals and humans. Prions are similar to viruses, but much smaller and act to cause abnormal function causes a change in the form of an intracellular protein. Cell proteinases can no longer breakdown this protein causing a buildup of the protein until cell function degrades. Eventually, enough cells are involved to cause clinical signs of disease.

To date, we have found no published research on TSE's in South American Camelids. There has been one published study that looked at the prion protein characteristics in a Dromedary Camel. Sheep and cattle have approximately 97% homology (identical sequences) in the prion protein. This homology may have some bearing on the fact that cattle and sheep suffer from a similar prion disease (sheep = scrapie; cattle = BSE or bovine spongiform encephalopathy). The dromedary camel examined had only 92 to 93% homology to cattle and sheep. At this time, we have no idea what the significance of this finding is. The differences in alleles may or may not be indicative of a species barrier to TSE's in camelids. To date and to our knowledge, no camelid has been diagnosed with a TSE. At Ohio State University, our pathologists examine over 100 llamas and alpacas each year. Brains are routinely inspected because of the common meningeal worm infection in the Northeast to the Midwest USA. Our pathologists have never seen any lesions similar to a spongiform encephalopathy.

The current state of knowledge of TSE in camelids is severely lacking. Scientific study will be needed to answer questions regarding species susceptibility of camelids to TSE's. TSE's are not directly contagious. or animals is in the event the animal is eaten. Eating prion infected tissues may result in infection in the exposed animal. Thus, all meat and bone derived proteins have been banned from ruminants feeds in the USA. Thus, alpacas would only become infected if they have consumed feedstuffs containing tissues from infected animals (e.g. sheep or cattle with TSE). Affected alpacas would only transmit the disease to their offspring or to other animals if they themselves or contaminated tissues were eaten.

This is strictly preliminary and is in response to questions we have been asked. We will continue to update and modify this report as more information is obtained.

David E Anderson, DVM, MS, DACVS
Head and Associate Professor of Farm Animal Surgery
Director, International Camelid Initiative
Ohio State University
College of Veterinary Medicine
601 Vernon L Tharp Street
Columbus, Ohio
Phone 614-292-6661
Fax: 614-292-3530
E-mail: Anderson.670@osu.edu