Poultry owners should be aware that there is currently an outbreak of the H5N2 highly pathogenic avian influenza (HPAI) associated with the migratory bird flyways in the United States, said Kansas State University animal scientist Scott Beyer.
The first problems were observed with small poultry flocks on the upper west coast, which were soon followed by infections on larger commercial poultry farms on the southern west coast. Recently, infections have occurred in the central flyway, a migratory route which encompasses three provinces in Canada and 14 U.S. states, including Minnesota, Missouri and Arkansas, where the disease has been confirmed in turkey flocks.
“Migratory fowl move north and south all over the earth through flyways as they move from nesting and feeding grounds,” said Beyer, who is a poultry specialist with K-State Research and Extension. “When they comingle in these areas, the avian influenza virus can sometimes be shared between the birds, which then return to their respective flyways bringing new variants of the virus which may have originated from other continents. Although this particular variant of the avian virus (H5N2) is more pathogenic than others, there have been no incidences of the virus spreading to other species or people. As is often the case, this virus has so far not been associated with actual disease symptoms in the migratory fowl so they should be considered potential carriers of the virus that is pathogenic to domesticated poultry.”
The safety of poultry meat and eggs is not an issue, Beyer said. This variant is the H5N2 strain of avian influenza and although it is harmful to birds, it has not been associated with a threat to people or the food supply. The commercial poultry industry in the U.S. routinely screens for all types of the avian flu in flocks and any positive flocks, even those with variants that are not harmful to birds or people, are not processed for food.
U.S. poultry industry routinely monitors for diseases
“Since viruses continually change form to avoid an animal’s immune system, the U.S. poultry industry does not allow any form of the virus to persist in commercial flocks unlike some other countries which allow the non-pathogenic viruses to persist in their flocks,” he said. “This reduces the risk of any virus from becoming more pathogenic thus harming birds and people or affecting our food supply. “
Small poultry flocks, gamebirds enterprises and commercial farms should be wary of potential exposure. Because it is thought that the virus has originated from migratory waterfowl as they move through their flyway, keeping them away from domestic poultry is most important. Many of these waterfowl likely visit local ponds for rest and feeding.
“If you have poultry near these ponds, you must eliminate all contact between them and your birds,” Beyer said. “This is especially important if you have your own waterfowl which could infect your poultry flock, but could also remain on the pond as other wild migratory birds stop by and then become infected by your birds.”
When these migratory birds feed in crop residues and farm ponds, they leave behind feathers and fecal matter that could carry the virus. Keeping yourself and pets away from these areas is crucial to reduce the chance of carrying the virus into your facilities, the K-State specialist said. Do what you can to encourage these birds to move away from your facilities so that you widen the clean zone around your farm as much as possible.
Gamebird operations with birds in netted flight pens are more vulnerable because migratory birds flying over pens could drop fecal matter and feather dander directly into the pens. Efforts to reduce anything that attracts feeding and movement of these birds around pens should be implemented. Nets should be repaired to prevent birds and animals from entering as much as possible.
Starlings and sparrows should be considered vectors as well, at least until proven otherwise, Beyer said. With the spring season now here in Kansas, these birds are looking for nesting and feeding areas and may be persistent in trying to enter your facilities. Nests should be removed as they try to build them and you should work to keep them from entering as much as possible. Clean up all spilled feed indoors and out so they are not attracted. Move or eliminate bird feeders away from domestic poultry areas. Netting areas where they like to nest will also discourage them. If you have roosting pigeons and starlings in your barns, these birds will always be potential sources of all kinds of avian disease and they should be eliminated from the facilities.
Wild birds are not the only threat
“Rodents are also sources of diseases,” Beyer said. “They are nocturnal, so usually show up after dark to scavenge leftover feed and you may not even know they are there. You should control rodent populations as much as possible using rodenticides or with the help of an exterminator.”
Don’t leave feed accessible at night. Place all feed into rodent-proof containers or areas. Do not allow feeders to remain full of feed overnight. Either move the feeders out or feed only what the birds will consume before dark.
Beyer said that people, autos and farm implements can carry the virus from one farm to another. At this time, it is a good management practice to limit any contact with birds on other farms.
“You should also be aware of any areas that you are driving or walking through on the farm or ranch where migratory birds have congregated as mud and dirt can help move the virus,” he said. “A good way to clean up exposed items is by using a cup of bleach in a gallon of water to soak or rinse the items. Be sure to rinse off the bleach after treating because it can be corrosive.”
Monitoring your birds for symptoms
Producers should be aware of bird illnesses and die offs, Beyer added. The primary symptom of avian influenza in birds is typical of most flu symptoms, so look for respiratory distress like coughing, ‘rattling’ (a raspy sound made when they breathe), sneezing, swelling around the eyes, and flicking of the head. Death may happen quickly, even before any signs of illness are noticed.
The Kansas Department of Agriculture is monitoring poultry flocks for the virus in Crawford and Cherokee counties, which are closest to the most recent known infection in Missouri, and on March 12 established quarantine zones in those counties.
If you have a flock with signs of this illness in these areas, quarantine your poultry and contact your local veterinarian and the KDA Division of Animal Health at 785-564-6601.
Also, as part of the monitoring process, the KDA is developing a map of the location of backyard flocks in Crawford and Cherokee counties. Backyard flock owners are asked to self-report their flocks by contacting KDA at 785-564-6601. This will assist with notification if further developments occur in this disease outbreak.
“Biosecurity is the best way to prevent your flock from contracting the infection,” Beyer said. “Knowing how the disease spreads and using good biosecurity will be the best line of defense.”