Friday, February 10, 2012

Testing Goats for Diseases

Last year I decided to test my herd of goats for CAE. I had never tested my goats for any diseases before this. The reason for not testing was mostly due to the fact that there is no veterinarian in my area who will do house calls. There are two vets who will look at goats but you have to take the goats to them. Seeing as I have 4 full-sized dairy goats and a full time job, setting aside an entire day to shuttle my goats to and from the vet’s office is out of the question.

I had thought about getting my herd tested before but never acted on it. When I first got goats I didn’t know what diseases were out there and what to test for. As I bred goats and sold goats I started get feedback from people about which diseases they wanted me to test for when they bought goats from me. I still resisted the testing for a while due to the lack of a veterinarian and not knowing if I could send in samples for testing without a vet. Finally I found a lab that would accept samples direct from farmers to test for CAE.

I tested my goats with Biotracking first. This lab accepts samples direct from farmers without needing a vet to sign off on them. The lab does CAE testing and pregnancy testing for goats using a small blood sample. The CAE test was only $4 per sample plus shipping. I was able to purchase the blood collection tubes and needles from Biotracking. My neighbor and I took samples from our 2 herds at the same time and sent them in at the same time, thus saving on shipping.

After doing the CAE test, I started looking into other things that people normally test goats for. CAE, CL, Johnes, and Brucellosis are the main diseases that warrant testing in most areas. CAE, CL, Johnes and Brucellosis can all be tested for with a blood sample. There are a few labs who will accept blood for these tests direct from the owners. Pan-American Vet Labs will test for all these diseases for a minimal fee. They do a good job and will have your results back to you within the week. WADDL (Washington Animal Disease and Diagnostic Lab) will also accept non-vet samples. They are considered the “Gold Standard” of diagnostic labs. Many people use them and most vets choose to use them when you request a test done. They do routine testing but can also do diagnostic testing on sick animals and necropsies on dead animals.

Whatever lab you chose to use, be sure that the test done is an ELISA test. ELISA is a type of blood assay test that is generally more accurate than other methods available. Most labs will say right on their websites if they do ELISAs. As with any tests, there can be false negatives or false positives. The ELISA test looks for the presence of antibodies in the blood for the particular disease. If the goat is newly infected or has a poor immune system they will test false negative. They may have the virus or bacteria in their systems but they don’t have the antibodies to them yet. If a goat has been exposed to antibodies from another goat, generally through colostrum, or has been vaccinated for the disease you are testing for, the goat will test false positive. They will show antibodies in their blood but may not actually carry the causative virus or bacteria. False results are a good reason to test your animals every year. A goat may carry the disease but show a negative test result for a while before they finally create antibodies. They could spread the disease through your herd without ever showing symptoms.

It is easy to test for these diseases. Simply take 2-3mL of blood from each goat, put it in a red topped vacutainer blood collection tube, label the tube to identify which goat it came from, and package the tube in a leak-proof container (usually a small Ziploc baggy that is wrapped in a paper towel and then placed in a larger Ziploc). Then mail the sample into the testing lab with the corresponding paperwork. Most labs charge between $4 and $10 per test per goat. Some charge a “lab fee” that is $10 or $20. Shipping can be most expensive with many labs requesting FedEx overnight at $18 per package. If you have neighbors with goats, I recommend collecting blood from as many goats as you can and sending it all in at once to save on lab fees and shipping costs.