Lone Star Pet Alert: Texas Pets at Risk for Heartworm, Even in Metro Areas

AUSTIN, Texas (April 2, 2025) – New data indicate that parasite-related illnesses, particularly heartworm disease, pose a growing threat to dogs and cats across Texas, including in major metropolitan areas such as Austin and the Dallas/Fort Worth area. Thrive Pet Healthcare is encouraging pet owners to keep their pets on veterinarian-recommended preventatives year-round to avoid parasite-related illnesses.

“Texas is one of the top states in the country for heartworm disease,” said Dr. Karyn Collier, Medical Director at Hillside Veterinary Clinic in Dallas, a Thrive Pet Healthcare partner hospital. “It affects both dogs and cats and being strictly indoors is not protection against the heartworm-carrying mosquitoes that can enter your home.”

According to 2024 data from the Companion Animal Parasite Council:

Carried by mosquitoes, heartworm can affect a dog’s heart and lungs. Some dogs show signs such as coughing, shortness of breath, fatigue after moderate activity, or weight loss, but many show no symptoms until the disease is more advanced. Fortunately, it’s very preventable with veterinarian-prescribed preventatives.

Heartworm is not just a canine concern—Texas is one of the top three states (alongside Alabama and Louisiana) for heartworm-positive cats, with a rate of 1 in 200, compared to the national average of 1 in 500.

In specific areas of Texas:

Even indoor-only cats can be infected by mosquitoes entering the home. Symptoms may include coughing, vomiting or difficulty breathing, but some cats show no signs at all.

“Previous research has shown that 1 in 7 dogs and 1 in 4 cats have fleas, which can cause itchy skin, tapeworms, or other infections,” said Dr. Johanna Diaz, Veterinarian at Thrive Pet Healthcare – Round Rock. “Ticks and fleas thrive in warm, humid climates, and Texas rarely gets cold enough to slow them down. Year-round prevention is the safest approach.”

“Prevention is absolutely critical because this disease can be silent and deadly, with symptoms of heartworm infection not appearing until the latter stages of the infection,” said Dr. Collier. “I strongly recommend that all dogs receive a heartworm preventative year-round along with yearly testing. There are heartworm preventatives available for cats, and your veterinarian can help discuss which products will work best for your pet.”

Veterinarian-prescribed preventatives are the most effective way to protect pets from parasites and the diseases they carry. Until June 30, 2025, participating Thrive Pet Healthcare hospitals are offering 15% off in-hospital purchases of popular parasite preventatives, including:

With a Thrive Plus membership, year-round protection is more accessible and affordable for pet parents. Member pets receive unlimited free exams,* $5 basic nail trims, and 10% off services like bloodwork, dental cleanings and spay/neuter—making it easier to stay on top of health concerns before they become serious.

Visit thrivepetcare.com to find a location near you that offers primary, specialty, emergency, and urgent veterinary care services, as well as participating Thrive Plus membership hospitals.