Heartworm disease is a serious and likely fatal disease among pets in the United States and many other parts of the world. It is caused by worms that live in the heart, lungs and associated blood vessels of affected pets. These foot-long worms can cause severe lung disease, heart disease and damage to other organs. This disease is most commonly known in dogs and cats. It can also live in many mammal species including wolves, coyotes, foxes, sea lions and, although rarely, in humans. With wild animals like coyotes and foxes now living closer in proximity to many cities, they are thought to be important carriers of heartworm disease.
Heartworm in Dogs and Cats
Dogs are a natural host for heartworms. This means that heartworms that live inside dogs can mature and produce offspring. Going untreated can lead to the increased quantity of worms. Dogs have been known to harbor hundreds of worms inside their bodies. It is important to get this disease treated because it can lead to long-term damage to the heart, voice and arteries and can affect the health of the dog even after the parasites have left. Prevention is the best option for this reason. If the disease is detected, treatment should be administered as early as possible to prevent the spreading of it.
Heartworm disease in cats differs quite a lot from dogs. It is less common in cats. Most worms do not survive to the adult stage. If the worms survives to adulthood, there will typically only be one to three worms. Although many cases go undiagnosed in cats for this reason, it is still important because even immature worms can cause damage with conditions like heartworm associtated respiratory disease (also known as HARD). The medication used to treat this disease in dogs cannot be used in cats, so the only means of protecting cats is prevention.
Signs of Heartworm
There are very little, if any, symptoms of heartworm disease in dogs in the early stages. If the disease progresses, the symptoms will develop. More pronounced signs will be seen in active dogs or heavily infected with heartworms. These signs may include a mild persistent cough, decreased appetite, weight loss, fatigue and reluctance to exercise. A swollen belly due to excessive amounts of fluid in the abdomen and heart failure can also occur. Blockages of blood flow can lead to a life-threatening form of cardiovascular collapse if there’s a significant amount of heartworms. Also known as Caval syndrome, symptoms include the sudden onset of labored breathing, dark bloody or brownish-colored urine and pale gums. Few dogs survive without the removal surgery of the heartworm blockage.
Unlike dogs, the signs of heartworm disease in cats can be on either end of the spectrum. The symptoms can be very subtle or very dramatic. Symptoms in cats can include coughing, asthma-like attacks, lack of appetite, weight loss and periodic vomiting. In rare cases, cats may experience fainting or seizures, difficulty walking or suffer from the accumulation of fluid in the abdomen. Sadly, in many cases the first sign is the sudden collapse or sudden death.