Alpaca Hematology – World Conference
Hematology of Alpacas Normal, Abnormal, and Studies from the Andes to Chinese Wormwood
with Susan Tornquist, DVM, PhD., Dip. ACVP College of Veterinary Medicine, Oregon State University
Alpaca blood cells are different than other mammals in that their blood cells are oval in shape. This unique size, shape, and hemoglobin concentration increases oxygen-carrying and exchange capacity. Alpacas have had to adapt to live in extreme conditions. In other species hemoglobin crystals are problematic but in alpacas they are common and not a problem.
Anemia is a decrease in number and/or size of (red blood cells (RBCs) or decrease in hemoglobin. The reduced oxygen-carrying capacity of blood presents as weakness and decreased exercise capacity. Moderate to severe anemia is relatively common in camelids and often unexplained. If bone marrow responds to anemia, it’s regenerative. If the bone marrow is not responding, it’s non-regenerative This classification is harder to do in camelids than in other species. It is also difficult to determine the cause of anemia with alpacas.
In an induced anemia study at Oregon State University, the researchers made the alpacas anemic (PCV<15%) over 2-3 days (PCV=Packed Cell Volume – way of measuring anemia). They replaced the plasma. The average number of days to detectable response was 2.6 (similar to dogs) Peak response to treatment was an average of 10.4 days (7 days in dogs). This is somewhat similar to llamas, but not entirely the same. Up to 2-3 months post anemia induction, several alpacas had not returned to a PCV within reference ranges. These alpacas had no infection, no iron deficiency, and were otherwise healthy. This brings up some questions: Why don’t they adequately regenerate? Do they develop a new “set point”? (It looks like they do!) Possibly alpacas are more adaptable to having a lower red blood cell count. Dr. Tournquist doesn’t believe this makes them more susceptible for other diseases.
S. Tornquist, L. Boeder, and C. Cebra found no significant problems when giving alpacas oxyglobin in an experiment where they gave it to alpacas with severe anemia. The oxyglobin was associated with improved off-loading of oxygen to tissues. Sadly, oxyglobin has become very difficult to obtain.
Mycoplasma haemolame is a blood parasite in Camelids. Formerly known as EPI it can be a cause of anemia. It was first described in Camelids in 1990. The parasite is usually susceptible to tetracyclines. Infection in camelids has been associated with mild to severe anemia, depression, lethargy, weight loss, possible reduced fertility, and sometimes death-especially in crias. It is also present in low numbers in healthy animals. Clinical signs tend to be seen in the most severe in immune-suppressed or stressed camelids.
Mycoplasma haemolame has been associated with shipping or movement from one premise to the anouther. In many herds, 20-30% of the alpacas are infected. It has been seen in crias <24 hours of age so it may be possible for the dam to give it to cria in utero. The research on this indicates that it can be transmitted in-utero but will not inevitably be transmitted in this way.
Dr. Tornquist has developed a sensitive, specific PCR-based assay for M. haemolame Conclusions Oxytetracycline: The organism is not usually cleared by standard oxytetracycline regime Once infected, many camelids may become chronic carriers Normal, healthy camelids may “clear” the infection on their own. Treatments such as enrofloxacin and artemisinin from the Chinese wormwood have been studied with llamas and were found to be ineffective.
If you have an alpaca that you suspect of being infected with M. haemolame you can send their blood to Oregon State for the PCR diagnostic test.
