July 17, 2015 – It may sound like something right out of a horror film, but brain worms are very real. Alpacas, which have been domesticated for thousands of years, commonly are infected with a worm called Parelaphostrongylus tenuis. This parasite can migrate to the brain, where it causes signs such as staggering, paralysis and seizures. Infections are frequently fatal, and standard deworming agents have been ineffective in treating most infected alpacas.
Now, veterinary scientists from Iowa State University have found reason to be hopeful. The researchers suspected that ivermectin, a commonly used deworming agent, would successfully treat infections cause by P. tenuis if it could reach high enough drug levels in the nervous system. Lots of barriers exist to substances getting and staying in the nervous system. Although this evolved as a protective mechanism, it makes nervous system infections very difficult to treat.
The Morris Animal Foundation-funded research team came up with a possible strategy to “trap” therapeutic concentrations of ivermectin in the nervous system for longer periods of time. The team knew that a common and safe antibiotic called doxycycline blocked a key nervous system pathway used to flush substances out of the brain. They discovered that doxycycline slowed ivermectin removal from cultured nerve cells, resulting in higher contact levels. Higher contact levels means improved efficacy in eliminating these devastating parasites.
The Iowa State scientists have submitted their findings for publication, and are optimistic that this new strategy will provide veterinarians with an inexpensive treatment that can save and protect alpacas from the toxic effects of deadly parasitic brain worms.
Morris Animal Foundation is a major funding source for alpaca and llama health issues affecting these unique and special animals. For more information about our programs, visit our website and join us in helping animals worldwide.