What is caprine arthritis encephalitis (CAE) virus in goats?
Caprine arthritis encephalitis (CAE) virus is a small ruminant lentivirus (SRLV), which is a group of closely related viruses that can cause chronic disease in multiple organ systems. Historically, SRLVs were named after the animal species affected, which included CAE virus of goats and ovine progressive pneumonia/maedi-visna of sheep. Further research demonstrated they should all fall under a single name, SRLV.
There is no treatment for SRLV and animals that develop clinical disease will not recover. Supportive care can be given in some cases to make less affected goats more comfortable.
How is CAE or SRLV virus spread in goats?
CAE and other small ruminant lentiviruses can be transmitted in multiple ways. In goats, it is transmitted via colostrum and milk, but there is evidence the virus can be spread through close contact with infected animals. Blood (e.g., contaminated instruments such as needles, dehorners, etc., and open wounds) is another way of spread. In sheep, close contact appears to be an efficient way to spread the virus in addition to the routes mentioned for goats. There is little evidence to support transmission at breeding, however, in-utero infection is possible.
Many goats acquire the disease at an early age and remain infected for life. Not all infected animals will show clinical signs, but they can still spread the virus.
What are the signs of CAE or SRLV in goats?
Goats can display a variety of signs of SRLV or CAE virus. Infection in goats younger than six months can result in encephalomyelitis and clinical signs including posterior weakness and ataxia progressing to paralysis. Clinical signs in adult goals include lameness, stiffness, reluctance to walk or rise, walking on knees, swollen joints, abnormal posture or movement, weight loss/wasting, firm and/or swollen udder, and cough or respiratory difficulties.
How common is CAE or SRLV in goats?
CAE virus is quite common in goats in the United States, with some estimates as high as 70%.
How is CAE or SRLV tested for in goats?
WADDL offers a Small Ruminant Biosecurity Screen, which includes caprine arthritis encephalitis (CAE), Caseous lymphadenitis (CL), and Johne’s disease. The lab also offers the Lentivirus Small Ruminant (Caprine Arthritis Encephalitis Virus) cELISA as a standalone test with volume discounting available.
Can an owner send samples directly to WADDL?
The diagnostic laboratory provides services primarily to veterinarians. Although WADDL will test blood or serum samples mailed directly from individuals, animal owners are strongly encouraged to work with a veterinarian in developing an SRLV control program. WADDL will send results to the veterinarian, and also to the owner if requested.
For more detailed information on CAE/SLRV testing, including guidelines on submitting samples, how long it takes to receive results, and understanding results, click here.
How much does it cost to test a goat for CAE or SRLV?
WADDL’s Small Ruminant Biosecurity Screen is $30 per test. If between 21 and 99 tests are ordered, a discount of $2 per test will be applied. If 100 or more tests are ordered, a discount of $5 per test will be applied.
WADDL’s Lentivirus Small Ruminant (Caprine Arthritis Encephalitis Virus) cELISA test is $10 per test. If between 21 and 99 tests are ordered, a discount of $1 per test will be applied. If 100 or more tests are ordered, a discount of $2 per test will be applied.
How often should I test my animals for CAE or SRLV?
You should test your animals for CAE/SRLV twice a year initially, followed by annual testing for herds that are primarily negative, with testing before breeding recommended. Any new animals brought into the herd should be quarantined and tested twice (at least 60 days apart) before introduction with other negative animals. For herds with both positive and negative animals, negative animals should be tested more often to adjust the milking order so negative animals are milked first.
How old does a goat have to be to test for CAE or SRLV?
Animals younger than 6 months of age should generally not be tested, but if a young animal is test-positive, it should be re-tested after six months of age because of the potential for influence of maternal antibodies passed from the dam to offspring.
Is there a vaccine for CAE or SRLV?
There is currently not a vaccine for SRLV or CAE. It is very difficult to create effective vaccines against retroviral diseases. Several different vaccine types have been experimentally tested, but none has provided adequate protection against SRLV infection.