Washington Animal Disease Diagnostic Lab

The CAE virus is primarily transmitted to kids via colostrum in the first few feedings after birth. Blood (e.g., contaminated instruments such as needles, dehorners, etc, and open wounds) is regarded as the second most common way of spread. Contact transmission between adult goats is considered to be rare except during lactation.

The diagnostic laboratory provides services to veterinarians. Although we will test goat serum samples mailed directly from an owner, we strongly encourage goat owners to work with a veterinarian in developing a CAE control program. We will send results to the veterinarian, and also to the owner if requested.

We recommend working with your veterinarian to obtain appropriate samples. Blood should be collected into a five or ten ml. "red-top" clot tube or serum separator tube. Leave the blood at room temperature for at least 1 hour to allow clot formation. We do not recommend separating the serum from the clot prior to shipment. Send blood sample(s) to the lab by overnight mail (FedEx (choose "Standard Overnight" for quickest delivery), UPS, or USPS).

It is not necessary to individually wrap each tube. The best method is to use padded pouches designed for blood tubes. If you do not have access to these, we recommend using a thick rubber band and grouping your tubes tightly into groups of 7-10 tubes. If you alternate the direction of the tubes they will stay tightly packed. Pack the tubes in a plastic sealable bag with absorbent material in with the tubes, and put another plastic bag around the first. Pack so the box can be dropped from a four foot height without breaking any tubes! An ice pack is recommended if the shipment is expected to take several days in warm weather.  If you chose to ship using Federal Express, specify "Standard Overnight Service."  Overnight package delivery should be sent to: WSU- WADDL Bustad Hall, Room 155N Pullman WA 99164-7034

Complete a WADDL General Accession Form for each submission (available on the main WADDL website in the "View Forms" link). If sending blood samples from multiple animals, also fill out the Identification Form for Multiple Animals. Ensure to number the tubes consecutively to match a key sheet with the animal names.

In-state (WA) costs are a $10 accession fee per case, and $4.20 for each sample. Costs for out-of-state residents are a $10 accession fee and $6.30 for each sample. Please make a check payable to "WADDL" for the proper amount.

Example: Washington State submission of 7 goat samples
Accession Fee	$10.00
Testing (7 x $4.20)	$29.40
Total	$39.40
Example: Out-of-State submission of 7 goat samples
Accession Fee	$10.00
Testing (7 x $6.30)	$44.10
Total	$54.10

CAE competitive ELISA (cELISA) tests are generally run once a week, on Thursday morning, with reports going out on Friday. During busy times, the test may be set more than one time per week. However, to be tested on Thursday, samples must arrive by Wednesday afternoon. Test results can be telephoned or faxed to the veterinarian and/or owner upon request. Veterinarians also can access laboratory reports electronically “on-line”; please call the lab to receive a secure web log-in (username and password). For security reasons WADDL does not e-mail laboratory results.

A positive result means the goat has been infected with the CAE virus and has made antibodies reactive with the CAE antigens used in this test. This goat is regarded as potentially contagious for the virus, especially if lactating. The antibody against CAE is not a protective antibody and infectious virus can still be spread in milk and blood of this goat. As many as 90% of positive goats may be free of clinical signs of the disease, and remain so for years or life. A young goat not infected with CAE virus which has received heat-treated colostrum containing CAE antibodies may also test antibody positive for several months because of passive transfer of maternal antibodies from the colostrum. We recommend re-testing these kids after six months of age to determine their true infection status. A negative result means that this goat is either not infected, or has been recently infected and is producing amounts of antibody too low to be detected. While the latter case does not appear to be common, it is a good reason to retest all negative goats when not in a closed herd. Goats that are negative should be periodically tested (twice a year for the 1st year, and annually thereafter).

Goats infected with CAE virus are infected for life. Thus a goat tested true positive by the CAEV cELISA test would not later clear the CAE virus infection. Occasionally a very young animal, fed heat-treated colostrum containing CAE antibodies may test positive and later negative from the decline of passively acquired antibodies in the colostrum. In some goats, seroconversion may be delayed for months after exposure. These "silently" infected animals test negative for antibody until the viral infection is activated by stress or other factors. It has not been determined whether these goats were infectious to other goats during the time they harbored the virus but remained seronegative. Lastly, although the CAEV cELISA test is a USDA licensed test showing excellent ability to detect CAE virus antibody true positive results it is not perfect test. The commercial manufacturer of the cELISA test publishes a test specificity of 99.6%, which means 4 in 1000 tests could generated a false positive result that upon retesting could test seronegative.

Yes, WADDL has a validated and USDA licensed (cELISA) for CAE virus antibodies. This test is more sensitive (ability to detect true positive animal) than the agar gel immunodiffusion (AGID) test (sensitivity of 85%-90% and specificity of 100%). Values for the CAE cELISA have been set by double testing goat sera by ELISA and a very sensitive research assay, called immunoprecipitation. The positive cutoff score for the cELISA had a sensitivity of 100%, and specificity of 99.6%, which means there is a false positive rate of 4 out of every 1,000 samples tested.

There is NO evidence that the CAE virus is transmissible to humans. However, there are other serious human pathogens which have been transmitted through raw milk. Consult your veterinarian regarding the public health hazards of consuming raw milk.

We recommend this screen for new animals entering the herd and animals producing milk for human consumption. This screen includes CAE, Johne's Disease, caseous lymphadenitis and Brucella. Tests are priced individually.

	In-State	Out-of-State
Caprine Arthritis Encephalitis	$4.20	$6.30
Johne's Disease	$4.20	$6.30
Caseous Lymphadenitis	$6.30	$9.45
Brucella	$4.20	$6.30

Heat treating colostrum will inactivate the CAE virus and prevent spread from the doe to her offspring. Colostrum from any doe may be heated to between 133 degrees and 138 degrees F (56 to 59 degrees C) and held at that temperature for one hour to inactivate the virus. An accurate thermometer is important. It is recommended to use a water bath or double boiler to regulate the temperature more closely. A large batch may be heat-treated and frozen in small feeding size portions for later use (about one pint per kid). If heated higher than 140 degrees F, the usefulness of the colostrum will be greatly reduced due to denaturing of beneficial proteins, including antibodies to other infectious microorganisms.

Twice a year initially followed by annual testing is suggested for herds which are primarily negative, with testing before kidding recommended. Any new animals brought into the herd should be quarantined and tested twice (at least 30 days apart) before introduction with other negative animals. In addition to CAE infection, new goats should be tested for Johne’s disease, and Brucellosis as a biosecurity screen (see #12). For herds with both positive and negative animals, negative animals should be tested more often to adjust the milking order so that negative animals are milked first.

Yes. WADDL is working with USDA scientists in the development of a polymerase chain reaction (PCR), which tests for CAE virus specific nucleic acid. Current PCR assays have lower specificity (more false positives) than the antibody assays. The PCR assay may become practical and financially affordable enough for routine testing, especially in goats that have delayed seroconversion. Additional information on CAE virus and other infections of livestock can be obtained by contacting your local veterinarian or the diagnostic laboratory at 509-335-9696, FAX 335-7424.

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