Southern states are racing to bring in measures to combat the threat from the plague of flesh-eating worms that is spreading across America.

Earlier this month, US officials confirmed the first domestic cases of New World screwworm in more than ​six decades, with the parasite detected in cattle, a goat, and a dog.

The fly larvae feed on living tissue, entering animals through ​open wounds and burrowing into the flesh. 

Domesticated house pets are one of the vectors through which the larvae, which cause deep, painful and potentially life-threatening wounds, can spread to humans.

So far, proven cases have been limited to Texas and New Mexico, but Oklahoma, Arkansas, California, and Georgia are among the states to bring in travel restrictions on rescue pets and livestock. 

In response to the crisis, Florida brought in emergency rules on Friday that mean the Sunshine State now has some of the strictest restrictions on animal movements in the country.

A female screwworm can lay up to 200 to 300 eggs at a time. If allowed to fester in a wound, the parasite will hatch in a victim’s tissue and begin eating them alive. 

Concerned pet owners should look out for wounds that fail to heal, accompanied by a foul odor or visible maggots, according to advice published by the United States Department of Agriculture (USDA). 

Owners are encouraged to report any symptoms of the parasite as soon as they are detected. Animals and people can be treated if the symptoms are detected quickly.

The Daily Mail contacted the agricultural departments in Texas, Arkansas, California, and Oklahoma for comment.

Texas has announced a plan to combat the spread of the parasite, including sterile fly releases, movement control zones, and treatment supplies. 

The USDA has calculated the risk of a nationwide infestation as 'very low' and says the US food supply is safe. 

New World screwworms do not thrive outside of tropical or subtropical regions. The agency said the risk to humans is 'very low'. 

On Thursday, the US Food and Drug Administration authorized the emergency use of a generic over-the-counter tablet to treat ​infestations caused by the New World screwworm in dogs and ‌cats, as the government steps up efforts to contain the parasite.

The agency said nitenpyram tablets, ​a fast-acting treatment, can be used in pets weighing at least two pounds and at least four weeks old, adding that the drug is expected ​to help kill most larvae within hours of the first ​dose.

Officials have warned that while most pets in the country face ​low risk, animals ​that have recently ⁠been in affected areas were more vulnerable.

The USDA's efforts to drive screwworms back south will be expensive. The agency estimated it would spend over $1billion on efforts to save cattle herds and other livestock.

About $750 million will go toward building and operating a plant capable of producing up to 300 million sterile flies a week. 

Releasing sterile flies has been used as a technique for decades. Because female screwworms mate just once, if they choose a sterile mate their eggs do not hatch and the fly population dwindles.

The goal is to protect the US cattle industry. Experts hope the parasite will not cause an immediate increase in near-record-high beef prices. Screwworms don’t affect food safety.