Screwworm outbreak stalls Texas pet adoptions, shelters struggle with capacity

Adoptions are on hold for thousands of dogs and cats in Texas as shelters grapple with restrictions meant to contain the New World screwworm, an invasive parasite that has crossed from Mexico into the United States for the first time in six decades. The halt in adoptions is putting animals at greater risk of euthanasia, according to numerous news reports.

The screwworm, which can lay eggs that hatch into flesh-eating larvae in the wounds or mucous of any mammal, has been detected in dozens of infections across southern Texas and southeastern New Mexico, with several cases in dogs. The parasite also poses a significant threat to the nation's $113 billion beef industry, prompting federal officials to close the U.S.-Mexico border to cattle movements. In response, most states have restricted the movement of animals from infested areas of Texas, halting the routine transfer of adoptable pets to shelters in other parts of the country.

Shelters feel the squeeze

The restrictions have created a logistical nightmare for shelters that depend on moving animals to regions where adoption demand is higher. The Gulf Coast Humane Society in Corpus Christi, for instance, was unable to send rescued dogs to New York state for weeks, causing the shelter's population to surge from about 325 to nearly 450 animals. The shelter, which typically sends around 500 dogs out of Texas each year, was forced to create additional space in outdoor exercise areas until New York relented—provided each dog received a veterinary certificate confirming it was free of the screwworm.

Mia Bendixsen, executive director of the Texas Humane Legislation Network, said the situation has disrupted operations across the state. "It's thrown a wrench into things, for small rescues as well as the bigger shelters," she said. "It's a real problem," agreed shelter director Mills, who noted that when her facility reaches capacity, municipal shelters have nowhere else to turn. "Then they have to euthanize more animals," she added.

A deeper adoption crisis

Even before the screwworm outbreak, Texas faced a surplus of homeless pets. In 2025, the state transferred more unadopted dogs (nearly 89,000) and cats (nearly 53,000) out of shelters than any other state, according to data. Texas also euthanized about 45,000 dogs—more than any other state—and nearly 29,000 cats, second only to California. The state's total stray animal population reached roughly 439,000 in 2025, also second to California.

Veterinarians and animal welfare advocates point to a combination of factors driving the overpopulation. Warm weather allows strays to survive longer and breed more prolifically. Additionally, many Texas pet owners are reluctant to spay or neuter their animals, particularly working dogs on ranches and farms. "There are people with working ranch and farm dogs, both male and female, who feel like the animal will lose some of its drive," said Lori Teller, executive director of the Texas Veterinary Medical Association.

Strains on shelter resources

The inability to move animals out of state has left many shelters overwhelmed. At the Houston Humane Society, animals are more stressed because of the crowding, according to director Aaron Grady. The shelter has managed to keep its population at around 200 by placing up to 300 additional animals in foster homes, but the network is stretched thin.

Combating the screwworm

The U.S. is not starting from scratch in its fight against the screwworm. The pest was largely eradicated in the country by the early 1970s through a program that bred and released sterile male flies. The U.S. Department of Agriculture is reviving that approach with a $750 million fly factory in southern Texas, set to open in April 2027, which will breed billions of sterile screwworm flies. Smaller facilities in Texas and southern Mexico are already dispersing sterile flies, and another is planned for Arizona.

Broader challenges ahead

Animal welfare experts say the screwworm disruption is compounding existing pressures on shelters, including the lingering effects of the COVID-19 pandemic, which stalled spay and neuter programs, and rising living costs that have led some owners to give up their pets. "A lot of them are just saying, 'I just can't, I just can't do it anymore,'" said Brandon Krodle, an animal control supervisor in Greenville, Texas.

Some states have moved quickly to contain the risk. Florida banned imports of rescued dogs and cats from Texas and New Mexico just a week after the first reported case in Texas this year. Many states now require veterinary inspections, with some shortening the validity of health certificates from 30 days to as little as three days.

Delcianna Winders, director of the Animal Law and Policy Institute at Vermont Law and Graduate School, said shelters need more money and space, but communities also should require animals to be spayed or neutered and have programs to provide those services if people cannot afford them.

For those on the front lines, the work is personal. Mills, the Corpus Christi shelter director, has a dog named Zuri who would have died in 2015 but for a trip from Paris, Texas, to Angola, Indiana. The screwworm restrictions have made such life-saving transfers far more difficult—but not impossible. As Mills put it, "We're not going to give up on them."