Heartworm disease is a serious and potentially fatal illness that can affect cats. The disease is caused by a parasitic worm called Dirofilaria immitis that is spread through mosquito bites. Once an infected mosquito bites a cat, it can take up to six months for the worms to mature and start causing clinical signs.
Heartworm disease in cats can be challenging to diagnose as the clinical signs can be subtle and non-specific. Here are the five signs of heartworm in cats:
1. Coughing: One of the most common signs of heartworm disease in cats is coughing. The immature worms migrate through the small arteries of the lungs, causing inflammation that damages the airways. Adult worms settle in the major blood vessels of the lungs, leading to a whole host of clinical signs, collectively known as “HARD” (heartworm associated respiratory disease). Coughing can be confused with other respiratory diseases in cats, such as asthma or bronchitis.
2. Difficulty breathing: Cats infected with heartworm disease may have difficulty breathing, with panting or open-mouthed breathing being obvious signs. This can start subtly, with just an increase in effort when inhaling or exhaling. The immature worms stimulate inflammation, and the death of adult worms can lead to more severe consequences.
3. Vomiting: Vomiting is a common side effect of heartworm disease in cats, and sometimes, the vomit may contain blood. Other gastrointestinal signs, such as diarrhea and lack of appetite, may be present. It is thought that non-specific signs of illness unrelated to the heart and lungs, such as vomiting, are a result of the immune response that causes system-wide inflammation.
4. Weight loss: Heartworm-infected cats may lose weight due to a general lack of appetite, potential vomiting, and diarrhea. Cats are sensitive to dietary changes, and even a slight decrease in food intake over time can result in a noticeable change in weight. However, there are many other causes of weight loss in cats, and a veterinary check-up may be necessary.
5. Respiratory failure: When an adult worm dies in the cat’s body, it releases toxins and inflammatory mediators that can lead to respiratory failure and circulatory collapse, often resulting in sudden death. Even if the cat survives, it can cause irreversible damage to the lung tissue. Respiratory failure can occur with no prior signs of heartworm disease, and it occurs in 10% of affected cats.
Since heartworm disease is a serious illness that can be challenging to diagnose in cats, it is essential to take your cat to a veterinarian if they are displaying any of these signs. Prevention is better than the cure, and there are various anti-parasite products available that can be tailored to your preferences. If you live in a heartworm-endemic area, talk to your veterinarian about getting your cat on appropriate preventative medication.
Currently, there is no approved treatment for heartworm disease in cats, making prevention vital. As always, it’s crucial to keep your cat’s regular check-up appointments with their veterinarian and discuss any health concerns you may have.
