Worms can actually invade your pet’s heart and cause significant damage to their heart, lungs, and arteries. Heartworms can grow up to a foot long and infect dogs, cats, ferrets, and many wild mammals. Heartworm disease has been diagnosed in all 50 states, but tends to be more prevalent in Texas and the southeastern states. Our team at Little Animal Hospital would like to educate you on these harmful parasites, and how to prevent your pet from becoming a victim.
How can my pet become infected with heartworms?
Mosquitoes are more than an irritating bug. These insects carry heartworm larvae, and when the mosquito bites your pet, the larvae enter your pet’s skin. Dogs are considered a natural heartworm host, which means the parasites can grow to adulthood, mate, and produce offspring while in your dog’s heart. Heavily infected dogs can have hundreds of worms in their heart. Cats and ferrets are atypical hosts for heartworms, and the worms do not usually grow to adulthood, but can still cause extensive damage in these pets. Cats can develop a condition called heartworm associated respiratory disease (HARD) as the immature worms invade the lung tissue.
What signs will I see if my pet has heartworm disease?
In the early stages, your pet may not show any signs. Active pets, heavily infected pets, and those with other health issues will have more pronounced signs.
- Dogs — Signs include mild cough, decreased appetite, reluctance to exercise, fatigue after only moderate exercise, and weight loss. As the disease progresses, your dog may develop heart failure, resulting in an enlarged belly because of fluid build-up in their abdomen. If your dog has a heavy infection, they may experience caval syndrome, which occurs when the large number of worms suddenly blocks blood flow in the heart. Your pet will then exhibit labored breathing, pale gums, and dark urine.
- Cats — The first sign in some cats is sudden collapse and death. Your cat may exhibit coughing, vomiting, decreased appetite, weight loss, and seizures.
How is heartworm disease diagnosed in my pet?
Early detection of heartworm disease is key to successful management and treatment. Testing requires a simple blood draw. Antigen and antibody tests are available.
- Dogs — Antigen tests are typically used for dogs. The blood is screened for proteins produced by the female adult heartworms. All dogs, except puppies younger than 7 months, should be tested before they are started on a heartworm prevention product. After beginning a heartworm preventive, all dogs should be tested in six months and then annually.
- Cats — Diagnosing heartworm disease in cats is more difficult. In addition to the antigen test, they will need an antibody test to determine if they have been exposed to heartworm larvae. X-rays and ultrasound imaging may also be needed for definitive diagnosis. Your cat should be tested before beginning a heartworm preventive, and then tested annually.
How is heartworm disease treated in my pet?
Any pet diagnosed with heartworm disease must be severely exercise-restricted, because physical exertion increases the rate of damage the heartworms can cause to your pet’s heart and lungs. Keeping your pet quiet, calm, and in a small area is paramount to a good outcome.
- Dogs — Once your dog’s condition is stabilized, a veterinary professional will decide on their best treatment protocol. Treatment takes at least 60 days to complete.
- Cats — No drug therapy is approved for cats. Your cat’s condition will be stabilized and their progress closely monitored. Spontaneous clearing occurs in some cases.
How can I prevent my pet from becoming infected with heartworms?
Heartworm preventives can be administered as a pill, topical application, or injection. The pills and topical applications are given monthly, and the injectables are given every 6 to 12 months. Regardless of the prevention method chosen, the medication kills the heartworms in their immature stages. For the medication to be effective, the immature stages must be eliminated before they molt to the adult stage, which can occur in as little as 51 days. If your pet’s medication is not given strictly on schedule, or if they spit out or throw up the pill, your pet is at risk for infection.
Heartworm disease is a serious, debilitating issue for your pet, but the condition can be easily prevented with annual testing and a year-round heartworm preventive. If you would like your pet tested for heartworms, or if you have any questions concerning your pet’s health, do not hesitate to contact our team at Little Animal Hospital to schedule an appointment.