Question:
I recently bought a female llama and added her to my herd. She must have had lice because now some of my other llamas have lice. I tried treating with pour on Ivomectin and got no results. How do I treat llamas for lice?

Answer:
Treating for lice can be difficult but first let’s address the issue of lice in general. There are two kinds of lice, sucking lice and biting lice and I am sure that there are probably subspecies in each of those. Lice are passed by the donor animal being in close proximity or in contact with the recipient animal. Lice can jump so they can in fact be passed without direct contact. A llama with lice will roll excessively and will rub on fences, trees, or anything else they can use to scratch themselves.

According to my veterinarian, Dr. Richard Ramseyer, sucking lice are usually treated with Ivomectin. He recommends using the cattle dosage, either by injection or orally. He has found that pour on is not as effective in llamas. (As a sidebar, I might add that I have tried pour on Ivomectin and found it less effective than injections. In addition, I found that pour on applied directly to the skin caused skin burns on some of the llamas.)

Biting lice do not respond to Ivomectin. They do respond well to a cattle lice powder. The one time we had lice we got them from a female that arrived for an outside breeding and had to treat the entire herd. The treatment of choice is a product that has a combination of Malathion and Methoxychlor which is available from several different manufactures. We used a lice powder named Ectiban-D made by Duravet, a cattle product, that we got from our local feed mill. We took a quart canning jar, punched nail holes in the lid and used it as a duster. We treated our entire herd three times before we finally got rid of the lice.

Llamas, with their heavy wool coats, are difficult to treat. Be sure to treat (dust) the dorsal midline (center of the back) from the head to the tail because lice will climb up and over the body. Once they come in contact with the lice powder they will die. I suggest that you also try to work the dust into the rest of the wool to the body with each treatment.
Biting lice have a two week cycle so their nits (eggs) hatch in two weeks and the llamas must again be treated. In fact, I found that 3 treatments in two week intervals was the most effective.

If you find one llama with lice, it is recommended that you treat your entire herd. You can also, as an added measure during the treatment period, apply lice powder to their dust bowls where they roll if the dust bowls will remain dry.

Treating lice is one of those herd management tasks that is not fun but sometimes necessary. First, identify which type of lice are present and treat accordingly. A broad dual approach using both Ivomectin and a lice powder can also be utilized if you don’t know which kind of lice are present. One injection of Ivomectin and three dustings with lice powder spaced two weeks apart should get rid of all lice.