Courtesy USDA/ Keith Weller Cattle located in an area where anthrax has been reported should receive a vaccine to help prevent the disease.

In certain parts of the U.S., late summertime means livestock producers should be on the lookout for the resurfacing of anthrax in their animals. Anthrax, which is caused by Bacillus anthracis, is a naturally occurring disease with worldwide distribution.

“Anthrax cases are not unusual, especially at this time of year. This is peak season for anthrax to resurface and affect livestock and deer,” says Dee Ellis, DVM, Texas Animal Health Commission executive director and state veterinarian. “Ranchers and livestock owners should be aware of recent anthrax confirmations in their area and consider vaccinating their livestock to protect against the disease.”

If an animal dies from the disease and isn’t properly disposed of by burning, the anthrax bacteria can spill out into the soil and remain dormant for long periods of time. The anthrax bacteria resurface on grass or forage in ideal weather and soil conditions during spring and summer months. By the time an animal shows signs of staggering, trembling or convulsions after ingesting the anthrax bacteria, death is expected. Animal carcasses, manure and bedding infected with anthrax should be incinerated until thoroughly consumed. This practice keeps wild animals from being exposed to the disease and kills the anthrax bacteria, preventing contamination at another site.

Anthrax is a reportable disease in the U.S. Farmers who notice symptoms of the disease in their livestock should notify the Center for Disease Control and their state health department.

“Outbreaks usually end when cool weather arrives and the bacteria become dormant. In the meantime, producers in or near historically affected areas should consult with their veterinary practitioner about the disease in general, and especially the need to vaccinate,” Ellis says.

The following biosecurity tips can be helpful to livestock producers who suspect they have an animal or carcass infected with anthrax:

• Wear long sleeves and gloves when handling carcasses or when working with or vaccinating livestock to avoid contaminating any sores or scratches on your arms or hands. See your doctor if you develop an unusual-looking sore on your hands, arms or other exposed skin. Although it’s rare to contract skin anthrax, this infection requires treatment with antibiotics prescribed by a physician.
• Practice good sanitation. Wash your hands after handling livestock, even if you wear gloves. Disinfect livestock equipment used on the animals or carcasses. Keep pets and children away from carcasses or bones of dead animals. Move healthy animals away from a pasture where animals have died from anthrax.
• Properly dispose of animal carcasses by burning to prevent exposure to other animals, such as wildlife or dogs.
• Vaccinate livestock if cases occur in the surrounding areas. Anthrax vaccine is a “live” vaccine, so it must not be administered with antibiotics. Vaccinated animals must be withheld from slaughter for two months.
• Restrict the movement of livestock onto or from an affected premise until animals can develop immunity through vaccination (about 10 days).

Flies can transmit diseases and reduce weight gain and feed efficiency in cattle.

They buzz and they bite, but the flies that cause a nuisance to people can also bring disease and nuisance to cattle. Fly control is essential in maintaining the health of dairy and beef cattle herds, whether in the pasture or the barn, says Purdue University entomologist Ralph Williams.

Pasture Flies
For pasture cattle, the two primary fly pests are horn flies, which are a biting fly, and face flies. Face flies don’t bite, but they feed around the eye tissue and can transmit bacterial conjunctivitis, or pink eye, to cattle.

“Horn flies are the No. 1 fly pest in the United States,” Williams says. “The threshold at which we recommend control is when those flies reach 200 per animal. It is not uncommon to see a thousand or more horn flies per animal.”

While horn flies don’t transmit diseases to cattle, they can cause economic loss by reducing cattle weight gain, feed efficiency and calf weights.

Barn Flies
For cattle in confinement, the stable fly is a biting fly that breeds in the accumulating feed waste and soiled bedding. As with the horn fly, stable flies don’t carry disease, but they, too, can result in economic loss for farmers.

House flies are the other common confinement pest. While they’re not directly associated with cattle, they can be a nuisance to people and surrounding neighbors.

Controlling Flies
“In confinement flies are best controlled through sanitation,” Williams says. “Farmers should identify and remove fly breeding sites, like waste and soiled bedding.”

In the pasture, however, fly control can be a bit more challenging. Topical insecticides can be effective as long as they stay on cattle for an extended time. One such method is through pesticide ear tags.

“Some of the products available are pyrethroids and organophosphates,” Williams says. “The pyrethroid-based tags generally are not very effective for horn flies because of a genetic resistance. Most of the organophosphate tags are very efficient for horn fly control. Abamectin is a new product that is available in some tags and has been very effective for both horn flies and face flies.”

Some tags also are available with a combination of insecticides that will control both face and horn flies.

Other fly-control options include self-applied dust bags in a forced-use situation, which cattle need to access daily, and pour-on insecticides, which can last up to a month. Feed-through insecticides, ingested with feed and released in the manure, can also disrupt flies. However, if not all cattle in the area are using them, flies could still be present.

As a biological fly-control option, farmers can introduce parasitic wasps to the farm. The females of these wasps lay eggs on fly pupae, and the wasp larva consume the fly before it emerges. Parasitic wasps may be purchased by biological pest control companies, which provide beneficial predator insects.