Morris Animal Foundation Study Sponsored by ARF

Prevalance of Mycoplasma haemolamae Infection in South American Camelids in the Southeastern United States

Principal investigator:

Alessandra Pellegrini-Masini, DVM, PhD (Mentor Lisa H. Williamson, DVM, Ms, DACVIM)
University of Georgia College of Veterinary Medicine

Mycoplasma haemolamae (Mh) is a bacterial parasite of South American camelids that attaches to red blood cells. Under stressful conditions, camelids harboring the organism can develop anemia from destruction of the parasitized red blood cells. Previous studies that used highly sensitive polymerase chain reaction (PCR) tests showed that asymptomatic Mh infections occur commonly in camelid herds in South America and the northwestern United States. This prevalence study was conducted in the southeastern United States to determine the prevalence of M. haemolamae infections in alpacas and llamas in that geographic area. Additionally, results from the polymerase chain reaction (PCR) assay were compared with microscopic evaluation of a fresh blood smear. A total of 422 healthy camelids (251 alpacas and 171 llamas) from 20 farms were sampled. Overall prevalence of M. haemolamae PCR positive animals was 27.9%. Ninety-five percent of the farms had at least one Mh PCR positive camelid on it. None of the camelids in the study showed any signs of illness. However, the PCR-positive camelids had a slightly, but statistically significant, lower packed cell volume (27.65%) when compared to the group of animals that tested PCR negative (29.28%). At this time, the significance of subclinical anemia in almost half of the Mh positive camelids is unknown. Compared to Mh PCR, microscopy of a thin blood smear to look for parasites on the red blood cells had a low sensitivity for identifying Mh positive camelids. The study also found that animals less than 6 years of age, and males, were slightly more likely to test positive on the Mh PCR. There was no statistical difference in body condition score or in fecal egg count between Mh PCR positive and Mh PCR negative camelids.

These findings support the concept that Mh infection is not associated with ill thrift or higher parasite burdens in camelids.