What Every Dog Owner Should Know About Heartworm Disease

It’s the first of the month, and you reach into your dog’s box of heartworm medication only to find that they’re out of pills. 

Heartworm medication is just another expense of pet ownership. You don’t know any dogs who have actually had heartworms – what’s the harm in skipping a month or two?

As it turns out, heartworm disease is much more common than you might think. It’s cheap and easy to prevent, but expensive and dangerous to cure. There’s also a few risks associated with monthly preventatives.

Read on to find out everything you need to know to make an informed decision to keep your dog safe.

How Do Dogs Get Heartworm Disease?

There’s only one way for dogs to get heartworms – by getting bitten by a mosquito that carries microfilariae, heartworm larvae. The disease is not contagious. An infected dog cannot pass it to other animals or to humans.

It takes about 6-8 months for an infected dog to show any symptoms.

Symptoms of Heartworm Disease include:

• Coughing
• Trouble breathing
• Fatigue, getting tired easily or unwillingness to play
• Weight loss, low appetite
• Rapid breathing or panting

As heartworms invade the dog’s heart and lungs, they’ll find it difficult to do even simple activities. If not caught in time, the disease will ultimately kill the dog.

Why Curing Heartworm Disease Is So Difficult

Your veterinarian will use a blood test to check for heartworms if your dog is showing symptoms or if your dog is about to begin monthly preventatives. Your vet may also test yearly if your dog is on preventatives to make sure they are working.

Treatment involves the use of several drugs over the course of a few months.

First, the vet will prescribe antibiotics to kill off Wolbachia, a harmful bacteria that heartworms carry.

They may also prescribe steroids to reduce inflammation.

At first, the vet will likely only prescribe a monthly preventative, as the pill kills larvae, but not adult heartworms.

After a round of pre-treatments, your vet can begin to eliminate adult heartworms. Your dog will need a series of injections into their back muscles, and your dog will need to stay at the hospital overnight for observation. The rounds of injections take a total of 6 months to complete.

In the meantime, your dog’s physical activity will need to be limited. An increased heart rate can agitate your dog’s coronary system, which will be weakened by the infection and by dead worms that may remain in the blood vessels. Only after treatment can the dog resume normal activity.

In total, heartworm disease treatment costs $400-1000.

How Pills Prevent Heartworm

Preventative pills do not actually keep your dog from contracting larvae. They actually kill larvae that your dog may contract so they can not grow into adult worms and manifest in your dog’s body. So, even while on the monthly preventatives, your dog may pick up larvae – but it’s unlikely that they’ll show symptoms.

That’s why, if you have an adult dog that does not currently take the monthly pill, your vet will need to perform a blood test before they can get started. The blood test costs about $50, and it’s worth the peace of mind. Some shelters and low-cost vet clinics offer discounted heartworm tests during summer months.

The Problem With Heartworm Medication

Like all medicine, heartworm preventatives can cause mild to fatal side effects. Some breeds of dog may be born with the MDR1 gene, which can cause them to experience side effects from ivermectin, one of the main ingredients used in preventatives. These breeds include the Australian Shepherd, Mini Aussie and Collie. You can have your dog tested for presence of the gene or your vet can help you find a medication that does not contain ivermectin.

The pills can interact with other medications and supplements. They can also trigger an allergic reaction or cause side effects in an otherwise healthy dog. Side effects of common heartworm preventatives include vomiting, diarrhea, fever, convulsions, and in rare cases, death.

Alternatives To Monthly Preventatives

Many dogs have no problems with a monthly pill. But you may decide to talk to your vet about fewer doses, or about not using the pills at all. This is a personal decision you will need to make with the help of your vet. If you don’t feel your vet is open-minded to discussing alternative options with you, they might not be the right vet for you.

You can ask about having your dog get the blood test every 6 months. This would allow you to catch the disease early before symptoms develop.

You can also ask about only having your dog on the pills when the weather is warm. Larvae can only develop inside mosquitoes when the temperature is above 57 degrees Fahrenheit for a few weeks, so it’s unlikely that your dog truly needs the pills during cold winter months.

Vets recommend year-round monthly preventative anyway because it’s easier for pet owners to remember. Additionally, many heartworm pills prevent other parasites like roundworms, whipworms and tapeworms, eliminating the need for regular deworming if taken monthly.

Your vet may agree, and tell you that it is okay to only give your dog treatment when the weather is warm.

Regardless of whether you decide to give your dog the pills, you should try to repel mosquitoes from your home and garden, as their bite can transfer many diseases to your pets and your human family members.

There’s many traditional and natural options to choose from. DEET-based bug sprays and spot-on treatments like Advantix keep fleas away. A lemon-eucalyptus based repellent will also work, but you should only use products on your dog that are designed for canines. Also, eliminate any sources of standing water on your property that may attract mosquitoes.

Every dog owner should know about heartworm disease and their options for preventing it. Share this post with your friends to spread the word!