Check out these adoptable pets in Corpus Christi The Gulf Coast Humane Society has partnered with the Caller-Times to show adoptable pets each month, featuring heartworm positive dogs who need some love. All the dogs in this month's adopt-a-pet series are heartworm positive. They are currently receiving treatment and will continue their treatment after adoption at no cost to you. What is Heartworm Disease? Heartworm disease is a serious illness contracted by pets and spread by mosquitoes. Texas has a higher amount of mosquitoes that are active year-round, so cases are typically higher in the state, according to Gulf Coast Humane Society communications manager Jackie McCollough.