Dear Friends,
Currently this is the most up to date information I have been able to find on WNV in llamas and alpacas Rocky Mountain Llama and Alpaca Association
Please take the time to read it.
There are three things I would like to address from this article, but first let me state that, as you probably understand, with any new disease we must all learn together to help control it. If you have any information that I have not seen, please feel free to send it to me. I would like to stay as up to date as possible so that I can serve you better. My service to you will be in the interpretation and application of any data that we can find. This actually stands for any disease. I am after all only human but I am trying.
1. Some have asked me about the three vaccine recommendation for llamas and Alpacas. My concern has been the origin of the test study, since I have seen no mention of collusion between the manufacturers and investigators I will have to assume the studies were valid. As of now, it seems that the recommendation is sound for the killed Fort Dodge product. Safety studies have not been done for the Meriel product as of this date, but I am sure they will be out soon. If the studies show that the Meriel product only requires two vaccines we will face the dilemma of switching. Live virus vaccines have historically caused more reactions than killed ones. This of course is why they tend to be more effective. because they cause more reaction and therefore more immunity! But if we go this route, most of you will have to give two more vaccines instead of one more, because it is a vaccine that works in a different manner. Imagine your immune system as a police station getting a picture of a suspect from the back, with long hair and a blue shirt. they will look for a suspect with long hair and a blue shirt. If they got a picture of the suspect from the side or front and saw a beard then they would look for the suspect based on that criteria. But BOTH police stations will need to get a good look at the picture, maybe look at it more than once before they can memorize it. The immune system works similarly, The white blood cells specifically the memory cells, need to be stimulated a couple of times before they can provide long term coverage, in this case it seems they need three passes to get it right. but because the vaccines in question look at different parts of the 'picture' we cannot just mix and match an figure they will get it right. In any event, the advent of a new vaccine is almost sure to drive the price down by next year. Currently the Meriel Product is priced around the same as the Fort Dodge Product.
2. This article has a nice section on the economic look at vaccination, though I know that for most of us there is a strong emotional aspect as well. For smaller herds, serotesting is less feasible than for larger herds but might be done for peace of mind. As you can see from the 8/19/03 summary of Dr. Kutzler's study, the risk of alpaca infection is 1/10th each herd owner will need to assess whether vaccines are commercially or emotional sound.
3. The risk of vaccination of pregnant animals is proportional to the risk of the disease. Modified live vaccines carry a greater risk of reaction and are usually not recommended. Fort Dodge product stands by its recommendation for vaccination of pregnant mares. There is no data for pregnancy safety in llamas and alpacas. I currently see killed vaccine as being less of a risk than the contraction of the disease.