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WLSB vet gives update

by Wyoming Livestock Roundup

During the Fremont County Farm and Ranch Days in Riverton, Wyoming Assistant State Field Veterinarian Dr. Teckla Webb gave an update on current and emerging livestock diseases from the Wyoming Livestock Board (WLSB) on Feb. 9.

During her presentation, Webb discussed avian influenza, trichomoniasis, brucellosis and vesicular stomatitis. 

Avian influenza 

According to Webb, the U.S. is currently experiencing the worst avian influenza outbreak in history.

“This is a viral disease, and it’s commonly called the bird flu,” she said. “It occurs naturally in wild birds, especially wild waterfowl.”

She noted wild birds, who do not appear sick, can carry avian influenza and spread it. 

There are two different types of this flu virus – low pathogenic avian influenza, which causes mild signs of illness and highly pathogenic avian influenza (HPAI), which is the cause of the current outbreak.

HPAI causes severe illness and a high death rate – up to 90 to 100 percent mortality within the first 48 hours in chickens, turkeys and other gallinaceous birds. 

The disease can be spread through direct contact with infected birds or indirectly through contact with virus-infected manure and virus-contaminated food, water, equipment, clothing, etc. 

As of Jan. 25, there has been 744 confirmed affected flocks in the U.S., of which 312 are commercial flocks and 432 are backyard flocks. A total of 58.2 million birds have been affected and have died either directly from the virus or have been culled to contain the spread of the disease, explained Webb. 

She noted Louisiana and West Virginia have reported zero outbreaks, but the state of Iowa has been greatly impacted with approximately 15.9 million birds affected. 

In the state of Wyoming, 11 total flocks have been affected, impacting 432 birds. 

“We currently have three premises under quarantine in the state,” said Webb. “These are backyard flocks.”

The last reported detection in the state  of Wyoming was on Feb. 1.

Currently there are multiple species of mammals which have been affected with HPAI. These species include skunks, raccoons, coyotes, bears, bobcats, foxes and opossums. 

Webb explained it is likely these mammals ate a bird carcass infected with avian influenza, and the animal subsequently became ill.

She shared many producers have asked if dogs can become sick. At this point in time, there has not been any reported cases of avian influenza infecting domestic dogs, but it’s certainly a possibility. 

On the other hand, ruminants such as cows, sheep and goats are not affected by avian influenza. Horses can become sick with other types of influenza viruses, but are not affected by the current strain of avian influenza.

Avian flu prevention 

Webb shared the best way to avoid avian influenza infection is to avoid contact with wild waterfowl and other wild birds. Producers can do this by fencing in poultry and putting a roof over the birds’ area.

She also encouraged producers to practice adequate biosecurity, including changing clothing, disinfecting shoes and washing hands before caring for livestock or after visiting other properties with poultry or hunting waterfowl. 

In addition, she also encouraged producers to limit visitor contact on their operations. 

Although rare, she noted humans can be infected with avian influenza. 

National Improvement Poultry Plan

The National Poultry Improvement Plan (NPIP), endorsed by the U.S. Department of Agriculture, offers flock certification for disease freedom from several hatchery disseminated diseases, including avian influenza. This is a voluntary, cooperative state and federal industry program.

Flock producers can purchase birds from NPIP-certified growers, ensuring birds are free from salmonella, mycoplasma and avian influenza. Sample collection for these diseases are completed by certified testers. 

WLSB is conducting a free NPIP Certified Poultry Testing Agent course in April. Webb encouraged those interested to reach out to WLSB for more information. 


In addition to avian influenza, Webb noted trichomoniasis is transmitted in cattle herds by infected bulls, which negatively impacts calf production and decreases herd fertility. 

She mentioned many producers in the state of Wyoming are familiar with trichomoniasis, and the disease has significantly decreased in the last decade because of the extensive work ranchers and veterinarians have done.

“Veterinarians in Wyoming test between 10,000 to 12,000 bulls annually, which is excellent, but we can’t let our guard down on trichomoniasis because bulls enter the state regularly,” said Webb. 

She added California, Texas, Oklahoma and Missouri have historically had numerous trichomoniasis cases. In 2022, she received the announcement of three trichomoniasis positive herds in Box Elder County, Utah potentially exposing nine other herds, in addition to two positive bulls in Summit County. 

“Trichomoniasis can come to Wyoming at any time,” said Webb. “If we’re not testing and not testing a lot, we could easily miss it, and it could spread.” 

According to WLSB rules, bulls must be trichomoniasis tested before the sale or lease of a bull for reproductive purposes. Bulls sold through a livestock market must have a negative trichomoniasis test within two weeks prior to the sale or the bull can only be sold for slaughter. 

In addition, any bull over the age of 24 months must have one negative trichomoniasis test and copies of the test records must be sent to WLSB before turnout in a common grazing area. 

Brucellosis and
vesicular stomatitis 

Brucellosis is an infectious, zoonotic disease caused by bacteria, meaning the disease can spread between people and animals. Webb encouraged attendees to notify their doctor if exposure is ever suspected.

Currently, the state has one herd under quarantine for brucellosis in Park County.

Vesicular stomatitis is a virus causing blister-like lesions which progress to painful sores affecting some or all of the following locations: the mouth, tongue, lips, nose, coronary bands, mammary glands and prepuce. 

In 2022, the state had 10 investigations for the disease, but after further testing, there were zero confirmed cases.

Horses and cattle, swine, sheep, goats, llamas and alpacas can be infected with the virus. People can also be affected and develop flu-like symptoms. 

The disease looks identical to foot and mouth disease in ruminants and swine. 

Webb encouraged producers to call their veterinarian immediately if they see any suspicious signs, including sores or blister-like lesions in the above locations affecting livestock or horses.

“We want to make sure we can provide the most accurate diagnosis as quickly as possible,” mentioned Webb. 

In closing, she shared the best way to avoid disease infection is to practice disease prevention and hygiene practices. 

Brittany Gunn is the editor of the Wyoming Livestock Roundup. Send comments on this article to

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