Did you know that even indoor cats are susceptible to heartworm infection? Our Ventura vets explain the danger of heartworm disease in cats, symptoms, treatment, and how you can prevent it.
What is heartworm disease?
Dirofilaria immitis, a bloodborne parasite, lives in the heart or near large blood vessels in infected animals. Female worms are 6–14 inches (15–36 cm) long and ⅛ inch (3 mm) wide. Males are roughly half the size of females.
Though heartworm disease is more commonly found in dogs than cats, it is possible for cats to become infected. Usually, cats have fewer adult worms than dogs (typically less than six).
Symptoms of Heartworm Disease in Cats
While heartworm disease is often undiagnosed in cats, even immature worms can do extensive damage by causing heartworm associated respiratory disease (HARD) and issues in the immune system.
Heartworms can even move to other parts of the body, such as the spinal cord, eye or brain. Severe complications including blood clots in the lungs and lung inflammation can happen when adult worms die in the cat’s body.
Signs of heartworm in cats may be subtle or apparent, and there are few, if any, early signs. Symptoms such as these may appear:
- Asthma-like attacks
- Difficulty walking
- Fluid accumulation in abdomen
- Fainting or seizures
- Coughing
- Periodic vomiting
- Lack of appetite
- Weight loss
Unfortunately, in some cases, the first indication of heartworms in cats is collapse or sudden death. While medications used to treat heartworm in dogs may be effective, they cannot be used on cats. As a result, while this condition is manageable in cats, there is no clinical treatment. Prevention is the most effective form of protection for cats.
Causes of Heartworm in Cats
A mosquito feeds on an infected cat, then picks up immature heartworm larvae which develop for 1o to 30 days inside the mosquito’s gut before entering its mouth parts. The infected mosquito then bites the cat and injects its infected larvae.
These larvae travel through the bloodstream to the pulmonary arteries and the right side of the heart, where they mature into adult heartworms capable of reproducing in approximately 6 to 7 months. A new crop of larvae is born around 8 months after the cat was infected and lives in the cat's blood for about a month.
While dogs have been known to have several hundred heartworms in their bodies, few of these larvae are usually found circulating in this area by the time testing occurs. Most do not survive to the adult age, as the cat is not a natural host.
Heartworms are transmitted through mosquitoes - not from one cat to another or from an infected dog to a cat directly. The risk of infection is highest when mosquitoes are present in the environment and actively feeding, and indoor cats are not immune; an infected mosquito may easily get into the house and infect a cat.
Treatment for Heartworm in Cats
Because heartworm disease is serious and progressive, the earlier your cat is tested and diagnosed, the better. Your veterinarian will take a small sample of blood from your cat, which will then be tested for heartworm proteins.
At Veterinary Medical and Surgical Group (VMSG), we process heartworm tests in-house, allowing us to provide same-day results. If a cat tests positive, additional tests may be ordered, such as X-rays or ultrasounds. While no drug has been approved to treat heartworms, the goal is to stabilize your cat and develop a long-term plan to manage the disease.
Treating heartworm infections in cats is risky. Though the heartworms may clear up, the damage caused may be permanent. If worms have been detected in the lungs, your vet may recommend chest X-rays every 12 months.
If mild symptoms are noted, small doses of prednisolone may be necessary to reduce inflammation. Severe heartworm disease could mean hospitalization so your cat can receive intravenous fluids, antibiotics, drugs to treat organ issues, and surgery in some cases.
How to Prevent Heartworm in Cats
We strongly advise all cats to receive year-round heartworm preventives orally once a month in mosquito-infested areas, beginning at the age of eight weeks. Mosquitoes are seasonal, so preventive measures should be implemented for at least six months per year. Prevention is a simple and safe procedure.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.
Do you suspect your cat has heartworm? With our in-house laboratory, we can provide same-day testing and results. Contact us today.
Your veterinary specialist in Ventura
We're always accepting new patients, so contact our veterinary hospital today to book your pet's first appointment.Related Articles View All
Anesthesia for Dogs
Most dogs are given anesthesia when they are spayed or neutered, and the majority of them will require it at least once throughout their lives. Our four-legged pets, like us, may require anesthesia as part of a surgery or procedure. Today, our Ventura vets discuss what you should know about anesthesia for dogs.
MRI for Dogs: How They Can Help
At Veterinary Medical and Surgical Group (VMSG) in Ventura, our board-certified veterinary neurologists use our in-house MRI to help diagnose a range of health issues in dogs from a ruptured cranial cruciate ligament to brain tumors. Today our vets explain why MRI scans for dogs can be helpful, and the conditions this technology can help diagnose.
FHO Surgery in Cats
FHO surgery can be an effective and relatively inexpensive surgical treatment option for hip problems in cats. Today, our Ventura vets describe the hip anatomy of cats, hip problems that could affect your kitty and what’s involved in FHO surgery and recovery.
Cataract Surgery in Dogs
Cataracts prevent light from reaching the retina of your dog, resulting in blurred vision and, ultimately, blindness. In today's blog, our Ventura veterinarians discuss the causes and symptoms of canine cataracts, as well as the surgery used to treat this eye condition.
Signs Your Pet Should See an Emergency Vet
Conditions that necessitate immediate medical attention in pets can arise in the same way that they do in humans. Ventura veterinarians explain when emergency care is necessary and what to do in those situations.