Rancher warns of Bluetongue in flock
During the Wyoming Wool Growers Association (WWGA) meeting held in Lander Aug. 10-11, Otto Sheep Producer Randall Jones discussed the effects of a Bluetongue outbreak in his own herd and offered advice on ways to control and prevent the disease.
“I’m sure a lot of ranchers don’t think they need to listen because they have never had Bluetongue in their area in all the years they’ve been in operation,” began Jones. “I am a third-generation sheep rancher. My grandfather and my father ran sheep on the place I run on now, and they never saw the disease in their herds. In fact, they didn’t even know what Bluetongue was, let alone anything about it.”
He continued, “I just want everyone to know, if it can happen to me, it can happen to anyone.”
Bluetongue virus
To begin the discussion, Jones explained Bluetongue is a virus related to Foot and Mouth Disease (FMD).
“Bluetongue is a cousin of FMD, and it demonstrates many of the same symptoms – swollen lips, nose and ears, lesions in the mouth and throat, high temperatures and lameness,” noted Jones. “They are so similar, in fact, animals with these symptoms need to be blood tested to differentiate between the two diseases.”
Jones further noted, in his experience, sheep infected with Bluetongue may also have blood in their urine, experience heart failure or contract secondary infections such as pneumonia.
“It is a very brutal disease,” he stated. “Producers with a Bluetongue outbreak can expect up to 50 percent mortality in their herd.”
Since both Bluetongue and FMD are considered reportable diseases, Jones pointed out if producers see these symptoms in their herd, they are required to report it to their veterinarian.
“After reporting, producers will be quarantined,” Jones stated. “I know a lot of producers think quarantine is a big deal, but it would take a very calloused person to want to spread this disease to other producers.”
Bluetongue transmission
Jones went on to explain Bluetongue is a blood-transfer disease primarily transmitted by biting midge flies.
“When I first got Bluetongue, I didn’t have any idea what a midge fly was. They are not very noticeable,” Jones said. “However, they do exist, and they transfer Bluetongue by biting a healthy animal after they’ve bitten an infected animal.”
Jones noted animals infected with Bluetongue can transmit the disease for at least two weeks before they start showing symptoms. He pointed out this makes it difficult for producers to simply go out into the pasture and remove sick sheep.
“By the time a producer pulls the sick ones off, they probably have 100 more that are infected and spreading the disease,” said Jones. “This makes it really hard to control the disease once it gets into a herd.”
Minimizing the risk of Bluetongue
Additionally, Jones explained because Bluetongue is a virus, antibiotics can’t be used to control the disease.
“There really isn’t a lot we can do for sheep sick with Bluetongue. It’s similar to going to the doctor with the flu – they pat us on the head and tell us to go home and get plenty of rest,” he said. “However, in my experience, there are a few things producers can do to minimize the risk of contracting Bluetongue.”
The first of these prevention methods, according to Jones, is to utilize a Bluetongue vaccine.
“After I got Bluetongue the first time, I started vaccinating my sheep, and I can vouch for the effectiveness of the vaccine,” he said. “Vaccinating is a pretty cost effective way to go. I think I paid 30 cents per dose for it, and it is pretty easy to administer.”
Although Jones believes vaccinating for Bluetongue is a good prevention tool, he noted the vaccine is hard to come by.
“I believe there are around 23 different strains of Bluetongue, but there are only three in the U.S. – type 17, type 10 and type eight. Vaccinating for one strain doesn’t provide resistance to any of the other strains,” Jones explained. “I had type 17 in my herd and could only find the proper vaccine in California, but they recently lost their ability to make types 17 and 10.”
The second Bluetongue prevention strategy mentioned by Jones is to keep sheep away from midge flies if at all possible. Since Bluetongue season stretches from late summer to early autumn and midge fly loads are lower at higher altitudes, Jones encouraged producers to stay at high-altitude summer allotments for as long as possible.
He further encouraged producers to ensure neighboring herds don’t have issues with Bluetongue before they bring their sheep home.
“If there are reports of Bluetongue in the area, do not bring sheep home,” he stated. “Look for pasture somewhere else or truck sheep to another state. Take them somewhere and feed them hay. Just do not bring them down into this stuff.”
“It is also helpful to keep sheep away from wet, marshy riparian area where midge fly loads are higher,” Jones added.
Insecticides are the third tool Jones recommended as a prevention strategy, noting there are two options available for producers – insecticide ear tags and applied insecticides.
“Insecticide ear tags are easy to apply, and they last a long time,” explained Jones. “The problem with these is they are fairly expensive at two to three dollars a piece. Some producers who have used them also claim they can cause infection in the ears.”
“Applied insecticide is the more cost effective option, but they don’t have the longevity we see with the ear tags,” he said. “In order to see the same effectiveness through the entire Bluetongue season, producers need to apply the insecticide every two weeks, which goes by really fast.”
Another problem with applied insecticide, according to Jones, is the labor it takes to apply it.
“We can’t just run sheep through the chute and spray the insecticide down their backs,” he stated. “In order for the insecticide to work, it has to be applied to every area of the sheep that isn’t covered by wool. This includes the dock, back, crotch, heads, ears and legs.”
Following Jones’ presentation, former Wyoming State Veterinarian Dr. Jim Logan also suggested producers visit with local Wyoming Game and Fish wardens and/or biologists about the diseases they are seeing in wildlife in the area as autumn nears.
“There is another virus known as epizootic hemorrhagic disease (EHD), which is in the same family as Bluetongue,” said Logan. “Oftentimes, when we see Bluetongue outbreaks in domestic herds, there is a corresponding issue with wildlife die-offs from EHD. If producers talk to their local Wyoming Game and Fish office, they might get a tip off which may make a big difference when it comes to preventing Bluetongue in their own herds.”
Hannah Bugas is a corresponding writer for the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.
