HOUSTON -

If you've been outside in Houston you know just how bad the mosquito problem is. It's not only a problem for humans, it's also a big problem for pets.

Studies show Texas ranks in the top 10 for heartworm infections in dogs and cats, and veterinarians said mosquitoes are to blame.

Dr. Lori Teller at Meyerland Animal Clinic said it's an all too common problem.

"It's exploding. We're seeing heartworms every single week. We're diagnosing them right now," she said.

Veterinarians said that when a mosquito bites a dog or cat, the larvae migrates to the heart. That's where parasitic worms can grow up to 12 inches long.

Teller said, "You can have this big mass of heartworms that's physically obstructing the flow of blood. It can also make it difficult for the valves to open and close. Just like any other disease, it can make your heart really big, causing a cardiomyopathy."

The animal then dies of cardiac arrest.

Prevention is key. Dogs and cats can get a topical treatment or a pill. There's also a twice a year injection for dogs only.

Symptoms of heartworms include coughing, lethargy and difficulty breathing.

Teller said that a pet bitten and infected today wouldn't show symptoms for several months.