Editor's Note: This story was updated with additional information at 4:55 p.m., March 28.
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REDFIELD, Iowa (DTN) -- Veterinarians are baffled as to why highly pathogenic avian influenza (HPAI) jumped across species and infected dairy cows in Texas and Kansas.
As of market close on March 28, the impact of avian flu on dairy prices has been negligible or nonexistent.
Positive tests were detected on unpasteurized milk samples and oropharyngeal swabs from cows in Texas and Kansas on March 25. Cows at a dairy in New Mexico had also shown a mysterious illness earlier in March. This is the first time HPAI has been detected in dairy cattle.
FOUND IN EIGHT COWS, TWO FARMS
USDA's report to the World Organization for Animal Health shows HPAI was found in eight cows at a farm near Dalhart area in Hartley County, Texas. The second case involved one cow near the Liberal area in Seward County, Kansas.
This report also showed that no markers of mammalian adaptation nor antiviral resistance were observed. Additional testing continues as well as viral genome sequencing to help better understand the cases and which strain of HPAI the cows have.
"The first detection of HPAI in dairy cattle in Texas and Kansas underscores the importance of adherence to biosecurity measures, vigilance in monitoring for disease, and immediately involving your veterinarian when something seems 'off,'" Rena Carlson, veterinarian and president of the American Veterinary Medical Association (AVMA), said in a news release.
"It has also been confined to a limited number of farms. Farms are stepping up their biosecurity measures to reduce their exposure to HPAI," noted DTN Contributing Analyst Robin Schmahl.
SYMPTOMS OF DISEASE
The sick cows had symptoms including a decrease in milk production, fever, change in stool and seemed to have a change in milk similar to mastitis. After a few weeks, the virus seemed to have run its course and cows recovered.
Phillip Jardon, dairy Extension veterinarian at Iowa State University, said during an industry webinar March 27 that this illness seems to affect older lactating cows and not fresh cows, younger cows or heifers.
"About 10% of the cows at these dairies have become sick and are put in the hospital pens. None have died from the virus, and for the most part, cows are back into production after a couple weeks," he said.
While it is not common to find these kinds of viruses jumping from one species to another, a goat in Minnesota recently tested positive for HPAI at a farm that housed chickens that had been depopulated for carrying the virus. The HPAI virus has also been found in some rodents at poultry facilities which have were depopulated, according to Jardon.
WILD BIRDS ARE VIRUS SOURCE
The source of HPAI at these dairies appears to be wild migratory birds. USDA officials stressed that this virus is killed in the pasteurization process and thus does not pose a threat to humans consuming milk or dairy products.
Dairies are only sending milk from healthy animals for consumption. The milk from affected animals is being diverted or destroyed and not entering the food supply.
IMPACT ON DAIRY PRICES
Schmal said the impact of avian flu on dairy prices has been negligible or nonexistent.
"The fact that cows do not need to be culled and will overcome it in a rather short period has not impacted the immediate outlook for milk and product prices," he said Thursday afternoon.
"Buyers of cheese and butter are focusing on current sufficient supplies and are not very concerned about a tightening of that supply in the near term. Milk production is increasing seasonally, as the market is in the spring flush period, which is offsetting any immediate impact on milk supply.
"Class III milk prices have declined about 40 cents per cwt this week and have fallen about 60 cents since the disease was first discovered. April, May and June Class III futures have made new contract lows to close out this week with April at $15.56 and May just slightly below $16," Schmal noted.
BIOSECURITY ON THE FARM
Several veterinarians, including Iowa's state veterinarian, Jeff Kaisand, joined the webinar Wednesday. He stressed the importance of reporting any changes in health of dairy cows to the herd veterinarian and the state department of agriculture.
"This is the perfect time to review biosecurity on your farm and know if you are taking the proper measures to keep diseases away from your animals," Kaisand said. "As of now, the USDA is not planning to quarantine dairy herds with HPAI, but this is an evolving situation, and we will keep you up to date on any changes."
WATCH ANIMALS FOR HEALTH CONCERNS
It was also advised to keep new animals isolated on the farm or in an off-farm facility to be sure they are healthy before being introduced to the main herd. While this virus is thought to be transmitted from bird to cow, they are unsure if it can be transmitted from cow to cow.
Monitoring the situation continues to be important as migratory birds make their way to spring and summer landing areas. Many states have dealt with HPAI in the poultry industry for the past few years. There have been no cases found in beef cattle, according to Jardon. Additional testing is underway on the positive dairy cows, including genome sequencing, to characterize the HPAI strain associated with these illnesses.
"While treatment is directed through herd veterinarians, it appears that these dairy cows need mostly supportive care with additional fluids. If a secondary infection is found, antibiotics would possibly be used, but all animals are cleared of infection prior to milk being considered safe for the food supply," Jardon said.
Kaisand stressed the importance of cleaning water sources frequently for preventative measures. As more information is found on the outbreak, officials will make further recommendations to livestock producers and consumers.
Read more coverage of HPAI's impact from DTN Livestock Analyst ShayLe Stewart, "Is Cattle Market's Reaction to HPAI Justified?" at https://www.dtnpf.com/….
Jennifer Carrico can be reached at jennifer.carrico@dtn.com
Follow her on X, formerly known as Twitter, @JennCattleGal
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