Most dairy goat owners are acquainted with common goat ailments like caprine arthritis encephalitis (CAE), Pnemonia, Caseous Lymphadenitis or abscess, contagious ecthyma or sore mouth, conjunctivitis or pink eye, and parasites, but there is another possible malady lurking on the horizon of the goat world-West Nile virus.
Though first discovered in the 1930s, West Nile virus was not recognized as a serious problem until the 50s when it was found in Egypt. There it caused meningoencephalitis, an inflammation of the spinal cord and brain in humans. It did not arrive in America until 1999, supposedly brought in by migrating birds.
John and Barbie Miner, Kersey, Colorado, documented a case of West Nile virus in dairy goats during the late summer of 2003.
Barbie Miner said her family and their trailer of show goats went to the Tri-State fair in Amarillo, TX, last summer (2003). About an hour after they arrived they noticed one of their Oberhasli does was not acting normal. Her eyes were glazed over, she was walking in circles and bleating, and she stood apart from her herdmates. The Miner’s became very concerned and found a local veterinary clinic to examine her and take blood samples for processing.
The Timber Creek Veterinary Lab ran a white blood cell count and found that to be okay but a little anemic. A West Nile Virus test was run, but the results took a week to get back.
The doe made it back home to Kersey, and the Miners, following veterinary advice, treated her with several drugs including: Nuflor, Terramycin drench, Bluelite, dextrose in a vein, Banamine for pain, vitamins, and CMPK (calcium) oral. The drugs seemed to work because the doe started to recover and is now doing fine. However, the Timber Creek lab, located near Amarillo Texas, confirmed a week after the fair/show that the Miner’s doe, sick at the Tri-State Fair in Amarillo, did test positive for West Nile virus.
Unfortunately for other Colorado goat breeders near Kersey, three other goats in their area died after showing the same signs as Miner’s Oberhasli doe. Blood tests were not done to determine if it was indeed West Nile or not, and a prescribed treatment regime was not employed. The Miners said they felt strongly that the other cases in their area of Colorado were West Nile and felt the state did not take preventive measures quick enough, such as spraying for mosquitoes.
West Nile is an arbovirus, which means the virus is kept alive only by transmission between a vertebrae host and blood feeding insects, usually mosquitoes in North America. West Nile is spread when a mosquito bites an infected bird; birds are usually the carrier of the virus. The virus then enters mosquito salivary glands and is then transferred when the mosquito feeds again. West Nile cannot be transferred by mammal-to-mammal contact.
The most serious problem West Nile causes is severe infection in the host from crossing the blood brain barrier. This crossover causes encephalitis, an infection of the central nervous system and inflammation of the brain. At this point there is no cure for West Nile virus. A vaccination is available for horses, but it has been known to cause pregnancy complications and is not labeled for use in other animals.
There has been confusion amongst animal breeders in determining which livestock species can be affected by this virus. Horses and birds are very susceptible to it, yet other livestock can and do catch it. Each North American state has protocol to follow when determining how to report this virus. In Kansas, after a host shows a high fever and other symptoms a test can be run but has to be done through a state approved laboratory for the diagnosis to have any chance of going on the official state numbers. The actual numbers of hosts infected with West Nile is debatable because of information not recorded due to missing protocol factors.
The cost involved with running and getting back test results of West Nile virus is substantial, around $50 to $60 per test. By the time the results get back, usually in seven to 10 days, the affected animal may have died. This is another source of confusion for dairy goat breeders and owners, who need to know what to do if they suspect an animal might be affected by the virus.
Veterinarians warn that the signs of West Nile in goats can be mistaken for other illnesses. They include a high fever, tilted head, staggering, and general depression. The high fever, tilted head and staggering all point towards encephalitis, which needs heavy-duty antibiotics and steroids for treatment. Once the infection crosses the blood brain barrier chances of a 100% recovery are slim. The goat may recover enough for breeding purposes, but very often will continue to show permanent signs of nerve damage.
This summer I had a personal experience with a young Oberhasli doe that came down with symptoms of encephalitis. The four-month-old doe kid was fine and doing well, but suddenly one day she could not hold her head upright. Her neck was severely twisted to the right side and it seemed as though her entire neck was out of place. My husband and I called our local vet and in consultation with him, treated her with vitamin B injections and penicillin. It didn’t help. Our vet then prescribed Nuflor and steroids. This seemed to help somewhat, but not enough to make us comfortable with the situation. We took her in to be examined and she found she had a high fever and an infected ear. Our vet suggested we run a West Nile test at that time, but we felt that the cost was prohibitive. We continued to treat her with Nuflor, steroids, and a topical ointment for her ear infection. Within a week she was doing much better, and seemed to be recovering but to this day, she still holds her head a little off to the side at times. The vet assured us that she could still be a good production doe, whether or not she had been afflicted with West Nile virus.
If expense had not been an issue for us, we would have chosen to run a test for West Nile virus as it would have been a good way to help inform the rest of the public that yes, West Nile was found in another domestic goat. However, we did what we could and recommend others with questionable goat problems, keep in close contact with a certified veterinarian, like we did, when confronted with the West Nile possibility.
Since there is no cure for West Nile it is very important for dairy goat breeders to practice prevention. Standing water needs to be drained; lagoons or ponds should have small fish placed in them that eat mosquito larvae or tablets that kill the larvae. Natural mosquito predators such as barn swallows, purple martins, and bats should be encouraged to stay in the area. Pesticides can be sprayed to reduce mosquito populations, however, using pesticides often has an adverse reaction on natural predators. Some states have started regular spraying programs to keep mosquito populations at bay. However individuals must be responsible and keep an eye on things in their own area and take preventive measures.
West Nile virus may be here to stay. There is less a chance for infection during cold months, as the mosquito species reported as carriers of the disease die after a hard freeze. But, when warmer weather comes and wild birds begin migrating north, the cycle begins all over again.
There is no cure for West Nile virus and there is no way to completely get rid of mosquitoes and other insects without wiping out the earth’s ecosphere. Therefore it is important to add West Nile virus prevention to goat management plans and do what can be done to prevent this threat from creating more dairy goat losses.
Jessica Bowers, her husband Tony and their three children, raise dairy and meat goats in central Kansas. Their herd name is TJS Gold; their local veterinarian is Chris Schwarz at Town and Country Animal Clinic, Newton, KS.