There are several unpleasant parasites that can cause serious health problems for our canine companions, but heartworm would have to be one of the nastiest. These stomach-churning worms live in your dog’s heart, lungs, and arteries and can potentially have life-threatening consequences for our furry friends.
But don’t despair — dogs can be treated for heartworms and in many cases will enjoy a full recovery. Even better, protecting your dog against heartworm is a whole lot easier than you might think.
So, how do heartworms affect your dog, how can these worms be treated, and what does heartworm prevention involve? Let’s take a closer look.
Signs of Heartworms in Dogs
The most worrying thing about heartworms for many owners is that, in the early stages of heartworm disease, many dogs show no ill effects at all. However, the longer an infection persists and the more serious it becomes, the more signs and symptoms will become apparent.
So, what signs should you keep an eye out for? A mild, persistent cough is often the first symptom many owners pick up on, while lethargy, fatigue, and a general reluctance to or intolerance for exercise can also ring alarm bells. A decreased appetite and weight loss may also occur, while advanced cases can also present with a swollen belly due to excess fluid in the abdomen.
In more serious cases, dogs infected with large numbers of heartworms can suffer from anemia and sudden, life-threatening blockages of blood flow within the heart, leading to cardiovascular collapse.
- Ears drop
- Persistent cough
- Reduced appetite
- Weight loss
- Lack of muscle tone
- Scruffy coat
- Swollen belly
The History of Dog Heartworms
Much of this can be put down to the formation of the American Heartworm Society in 1974. Not only do we now have a much deeper understanding of how heartworms spread and the health consequences they have for our pets, but we also have much more successful treatment methods and preventative products that are more or less 100 percent effective at protecting dogs against heartworms.
Although heartworms were originally thought to be limited to warm, humid coastal areas with high mosquito numbers, they've since spread into much larger areas. Surveys conducted over the past few areas have shown the spread of Dirofilaria Immitis from the sub-tropical southern and southeastern states to the colder climates of northern states, including inland areas. In fact, while some areas in the northwest of the country are still relatively free of heartworm, the disease has been diagnosed in all 50 states.
The Science of Heartworms
Adult worms can grow up to 12 inches long and then reproduce immature heartworms, known as microfilariae, into your dog's blood.
Every three years, the American Heartworm Society conducts its Heartworm Incidence Survey. The 2016 survey revealed that:
* The average number of dogs diagnosed per clinic in 2016 rose by 21.7 percent compared to 2013.
* 23.3 percent of veterinarians surveyed reported seeing more heartworm cases in 2016 vs. 2013, while 19.8 percent reported a decline in their practice areas.
* No US state is completely free of heartworm disease.
* The top 10 states with the highest rates of heartworm incidence were Mississippi, Louisiana, Arkansas, Texas, Tennessee, South Carolina, Georgia, North Carolina, Alabama and Florida.
* Of those top 10 cities, only Alabama, Louisiana and Texas saw decreases in the number of dogs diagnosed.
Heartworm Diagnosis and Treatment
Your veterinarian can administer a simple heartworm test by taking a small blood sample from your pet, and the American Heartworm Society recommends that you get your dog tested every 12 months. And while no dog lover wants to hear that their pet has tested positive for heartworm, the good news is that the disease can be treated.
The first stage of treatment will usually involve your dog being hospitalized so that an adulticide can be administered to kill the adult heartworms. Monthly medication can also be given at home to eliminate the microfilariae in the bloodstream, and you may need to restrict your dog's activity levels for at least four to six weeks.
In the most serious cases, where dogs suffer a life-threatening form of cardiovascular collapse known as Caval Syndrome, immediate surgical removal of the heartworm blockage may be required.
How to Prevent Heartworms
Heartworm is preventable. Heartworm infection is virtually completely preventable in dogs and cats, and heartworm medications are nearly 100 per cent effective when administered properly.
All-year-round prevention is needed. The American Heartworm Society recommends giving your dog a heartworm preventive 12 months a year.
Start them young. According to the American Heartworm Society, puppies should be started on a heartworm preventive as early as the product label allows, and no later than eight weeks of age.
Look into prevention options. Heartworm preventive medications are prescribed by your veterinarian and are available as a once-a-month chewable, a once-a-month topical, and a twice-a-year injection. Speak to your veterinarian about the best option for your pet.