Caprine Health

UPDATE ON CAPRINE ARTHRITIS ENCEPHALITIS (CAE) VIRUS

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QUESTIONS MOST OFTEN ASKED

WASHINGTON ANIMAL DISEASE DIAGNOSTIC LABORATORY

WADDL

Caprine arthritis encephalitis (CAE) is a viral infection of goats which may lead to chronic disease of the joints and on rare occasions encephalitis in goat kids less then six months of age. The CAE virus is intimately associated with white blood cells; therefore, any body secretions which contain white blood cells are potential sources of virus to other goats in the herd. Since not all goats that become infected with CAE virus progress to disease, it is important to routinely test goats for infection by means of a serology test which detects viral antibodies in the serum.

Over the past several years, we have had numerous inquiries about CAE virus, how to test for it, and most importantly, how to take steps to control the infection in goat herds. We have taken some of the most frequently asked questions and presented them along with some short answers.

What are the major means of spread of the virus? The CAE virus is primarily transmitted to kids via colostrum in the first few feedings after birth. Contact transmission between adults goats is considered to be rare except during lactation.

What does a positive, negative, or suspect result mean? 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 a potential shedder of the virus, especially if lactating. The antibody against CAE is not a protective antibody, and although strong antibody reactions may be detected in the test, infectious virus can still be shed by this goat. As many as 70% of positive goats may be free of clinical signs of the disease, and remain so for years or life. A young goat which has received heat-treated colostrum containing CAE antibodies may also test positive for several months because of passive transfer of maternal antibodies. We recommend retesting these kids between six and nine months of age to determine their 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 (annually, if not twice a year). A SUSPECT result may reflect recently infected goats, young animals who have received colostrum containing antibodies, or animals reacting abnormally in the test. Predictability (or reliability) of test a result is often used to assess the overall accuracy. For the CAE ELISA, the predictability of positive and negative test results is very high. Unfortunately, the ability to predict that a suspect test result represents a true positive or true negative is low, necessitating the retesting of suspect animals. Likewise, there is not data at present to indicate that the actual ELISA score within the suspect or negative rage, whether high or low, is an indicator of whether an individual animal will become positive or negative in the future. Consequently, management decisions based on these values are not valid. There will be no charge for retesting suspect sera submitted between 30 and 90 days after the original samples. Please include the original WADDL number when submitting the follow-up sample.

Can an animal testing positive ever test negative on future tests? It is unlikely that a CAE virus infected adult goat which has tested positive would ever test negative in the sensitive ELISA test. 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 was not determined whether these goats were infectious to other goats during the time the harbored the virus but remained seronegative.

Is there a difference in the types of serology tests available for making a diagnosis of CAE virus infection? Yes, the Washington Animal disease Diagnostic Laboratory has a kinetic Enzyme Linked Immunosorbent Asay (ELISA) for CAE virus antibodies using detergent disrupted whole CAE virus as the antigen. This test is more sensitive (detects true positive animals) than the agar gel immunodiffusion (AGID) test. Values for the CAE ELISA have been set by double testing goat sera by ELISA and a very sensitive research assay, call immunoprecipitation. The positive cutoff score for our CAE ELISA had a sensitivity of 95.2%, with no false positive results. This is a great improvement over the commercial CAE/OPP AGID test, which had a sensitivity of 56.1% in one study. It is also an improvement over the 90.7% sensitivity of our CAE virus AGID test. We have found no CAE-AGID positive, ELISA negative animals in double testing of over 1,200 samples.

Is it okay to drink raw milk containing the CAE virus? There is no evidence that the CAE virus can infect humans. However, there are some serious human pathogens which have been shown to be transmitted through raw milk. Consult your veterinarian regarding the public health hazards of consuming raw milk.

In heat treating colostrum, what times and temperatures should I use? Colostrum from any doe may be heated to between 133 and 138 degrees F (56 to 59 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 1 pint per kid). If heated higher than 140 degrees F, the usefulness of the colostrum will be greatly reduced due to denaturing of proteins, including antibodies.

How often should I test my animals? Yearly 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 before introduction to other negative animals. 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.

May an owner sample goats and send the serum directly to that lab? The diagnostic laboratory primarily 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.

 How should I ship samples for CAE virus antibody testing?

We recommend working with your veterinarian to obtain appropriate samples. In general, blood should be collected into a five or ten ml. “red-top” clot tube or serum separator tube, and immediately sendt to the lab by overnight mail. There is no need for an ice pack if shipped by an overnight mail service. We do not recommend separating the serum from the clot prior to shipment. Please number the tubes consecutively to match a key sheet with the animal names.

Overnight package delivery should be sent to: WSU- WADDL, 155N Bustad Hall, Pullman, WA 99164-7034. WADDL offers discounted shipping throught Federal Express (1-3 lbs. $8.50, 4-5 lbs. $11). An ice pack is not necessary for overnight shipment on recently drawn blood. Use the WADDL accoount number on the air bill - #2112-4551-4 and specify "Standard Overnight Service". Shipping fees will be added to the testing charges.

The address for post office mail is Washington Animal Disease Diagnostic Laboratory (WADDL), P.O. Box 2037, Pullman, WA 99165-2037. An ice pack is recommended if shipment is expected to take several days in warm weather.

How long does it take to get CAE virus serology results?

CAE ELISA 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. Depending on the day the samples arrive, it may take up to a week to get results. Results can be phoned or faxed to the veterinarian or owner.

What does it cost for testing at WADDL?

In-state (WA) costs are a $10 accession fee per case, and $3.00 for each of the first ten samples, then $2.40 each from 11 on. Costa for out-of-state residents are $10 accession fee and $4.50 each of the first 10, then $3.60 each from 11 on. Please do not send payment with the samples. We will bill the veterinarian or owner directly.

Are there new test methods on the horizon? Yes, WADDL is working with USDA scientists in the development of a “competitive” ELISA using monoclonal antibodies against the immunodominant CAE virus antigen.

This test appears to be both very sensitive and highly specific. Perhaps in the future, polymerase chain reaction (PCR) testing for viral specific nucleic acid will 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 the diagnostic laboratory at 509-335-9696, fax 509-335-7424

Lice Control

Synergized DeLice is a product which is inexpensive, can be bought over the counter in gallon bottles, and is easy to apply. A squeeze bottle with a small applicator tip is desirable. (Ladies: Ask your beautician to save permanent solution bottles. They work wonderfully.)

Lice are easy to kill. Only a small amount of DeLice is required and is applied along the back of the goat from the base of neck to base of tail. Results should be visible within seven days.

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Hello Goat Showmen and Breeders,

First I would like to convey our condolences and our prayers to the families of the victims in Pennsylvania, New York City, and Washington D.C. Though these times have been rough, I know my country will unite and help those in need.

The FFA is back and in full force, Capra Products would like to remind our young showman about our Capra-Cool calming agent for those goats who just cant seem to get the program down. Also, dont forget about the Caprabio-Caprine Conditioner that can help give your show goat the edge it needs in the ring. If your're having a hard time finding products designed for your goats health, remember that all of the nutritional items offered by Capra Products are formulated and labeled specifically for your goats needs.

Please visit our online partner GoatMarket.com and browse through their message boards to find out about buying or selling goats. It also would be a great place to advertise your ranches capability. At GoatMarket.com you can also find out what the markets are doing nation wide and keep up to date with real time agricultural news. Give them a visit.

Capra Products has other news as well our CL Vaccine push in the first two weeks of recieving CL Forms already is representing over 800 head of goats. We need more forms to be sent, but the momentum has begun. You can print out the form from our website. Just click on the button that says CL Form on our home page. You can also find it at "http://www.tennesseemeatgoats.com/articles/vaccineform.htm Please choose to get involved. You can see what we are trying to do at the Capra Products website. Just click on the button that says "Capra Products pushes for CL Vaccine".

Also, all you dairy goat breeders. We have the new V Strip 2 sub-clinical mastitis diagnostic test now available. This test enables you to test milk in the barn by dipping one single strip about the size of your finger into your drawn sample. Within 30 minutes you can get a somatic cell count (White Blood Cell Count) and also a read to tell you if there are abnormal amounts of staph and strep bacteria strains present in the udder. It is very accurate and can be used not just to test but also to see if anti-biotics are working. It can also demonstrate that even if the goat milk is high in somatic cell count, it doesnt mean that bacteria is present as many of you know can be the case in late lactation. Please call 972-679-0358 for information or ordering. It will soon be available for online purchase.

Capra Products would also like to inform our goat raising communtiy that Capra Products has the ability to produce and supply your farm with any size bulk order. Our products are not just designed for the goat showing community. If your soil or feed is insufficient in supplying your animals with the much needed levels of vitamins or minerals such as copper we can fill that void. Just contact us through E-mail at Scottr@CapraProducts.com or at 972-679-0358

Please research our products through our website at www.CapraProducts.com. Our nutritional products can provide your animals with the added or lacking nutritional boost they need to succeed. All our products are labeled and formulated just for goats, showing our commitment to you. We offer our items at concentrated levels in a 1 pound as well as a 5 pound to not only give you usage longevity but to also spare you astronomical shipping charges. With the showing season preparing to heat up for our FFA crew as well as our open show breeders at the majors please try Capra Products and judge for yourself.

Best Regards,

Scott Robbins

Capra Products

A client brought a litter of golden retriever puppies to my veterinary clinic for inoculations and worming. As the look-alike pups squirmed over and under one another in their box, I realized it would be difficult to tell the treated ones from the rest. So, I turned on the water faucet, wet my fingers, and moistened each dog's head when I had finished.

After the fourth puppy, I noticed my talkative client had grown silent. As I sprinkled the last pup's head, the woman leaned forward and whispered, "I didn't know they had to be baptized, too."