Adopting a Dog With Heartworm Disease

Adopting a Dog With Heartworm Disease

You’re at the shelter–or maybe at an adoption event–and an adorable dog catches your eye. She’s full of tail wags and smiles, and as soon as your eyes meet, you know that she’s the one. But when you approach the shelter representative to ask about her, they tell you that she has heartworm disease. They also tell you that heartworm disease is expensive to treat, and that it can come with health complications.

Google only makes it worse. When you look up heartworms, your screen is bombarded with images of hearts laced with what looks like spaghetti, and admonishments from veterinary sites to always use monthly heartworm preventative. It lists how dogs with heartworms can have a cough, low energy, and exercise aversion. How it not only affects their heart, but their lungs and other vital organs. Suddenly you aren’t so sure about bringing that adorable dog into your life.

Wren, the heartworm positive pup we fell in love with.

When I fell in love with a heartworm positive dog at an adoption event five months ago, I went through the same cycle of emotion. The internet is chock-full of information about why you should prevent heartworm, and how bad it is when dogs and cats become infected with it–but there is hardly any information out there for people considering bringing a dog who already has heartworm into their family.

I had so many questions–will she ever be able to exercise? Will her heart and lungs recover? Will her lifespan be impacted? What is treatment like?

Wren’s first day home.

When we first met Wren, she couldn’t walk more than twenty feet without lying down for a break, and she had the characteristic cough that originated deep in her lungs. We’re an active family, and I was concerned that she’d never be able to join us for most of our favorite activities.

Despite those concerns, we adopted Wren. Only three months after her treatment, and she’s good as new–pulling on her leash with shocking strength for a dog her size, matching our 90 lb husky mix step for step on hikes, and swimming like a fish.

So today, I’m stepping up on the podium to write about heartworm disease from an adopter’s perspective–and to encourage you not to let a positive diagnosis stop you from adopting.

First, the facts about heartworm disease:

  1. It is not contagious from animal to animal–it is spread by mosquitoes.
  2. It can be contracted at any point in the year. In the South, often it is warm enough for mosquitoes to survive through the winter. Even in colder climates, mosquitoes can live indoors through the winter.
  3. It can be prevented through the use of a monthly heartworm preventative, like Heartguard, which is an oral chew, or an injection like ProHeart6, which provides protection for six months. The preventative kills the microfilariae, or larvae, that exists in the blood and prevents the heartworms from developing further.
  4. However, the only way to treat a dog that has already contracted heartworm disease is through your vet–using a preventative will not cure the disease.
  5. Both cats and dogs can contract heartworm disease. However, cats are better able to resist becoming infected by it.
  6. There is no real cure for cats who contract heartworm, but dogs have several different treatment courses that are highly successful.
  7. Due to our warm, moist climate, Mississippi has one of the highest prevalence rates of heartworm disease in the United States.
  8. For this reason, our shelters fill up with dogs with heartworm disease, and these wonderful dogs wait and wait in shelters–adopters tend to be less willing to take them on.

Now that we have the facts, we can dive into what actually adopting a dog with heartworm is like. The first step when  bringing a heartworm positive dog into your home is consulting your vet. Treatment can range from $300 to $1,000 depending on whether the dog experiences complications.

Wren and her new sister Chara, before Wren’s treatment began.

While this might seem steep, remember that by adopting, your dog will already be spayed or neutered, have up-to-date vaccinations, and be microchipped. A spay or neuter alone can be far more expensive than $300 in parts of the country. Many shelters (including ours!) will also provide an adoption fee discount for dogs with heartworm disease, and in some cases the shelter is able to help fund treatment, so it ends up being a fairly good deal.

In our case, we felt that the money was a small price to pay for 10+ years with Wren in our family.

The treatment itself takes one to two months to complete. On day one, the dog is injected with an immiticide, which begins to kills the adult heartworms. Your vet will keep the dog overnight for monitoring, and then will inject the dog with a second injection again the next day. Usually the injection is given in the hindquarters, and can result in extreme soreness in that area for a few days (so don’t be surprised when your dog yelps or even nips at you when you first try to pet them there!).


From the time of the first injection, it is very important that your new pal be kept very calm–as the worms die, they have the possibility to cause complications if the heart starts pumping too hard. Many veterinarians recommend keeping the dog crated during the first month after the injection to prevent complications from occurring. For bathroom breaks, the dog should be kept leashed. With Wren, she seemed stressed in the crate, and stayed far calmer when we allowed her to snooze on the couch. So use your best judgement, and remember that the goal is to keep them as mellow as possible.

Some vets will also recommend a “slow kill” version of treatment, where the dog is given one injection, the adult worms are allowed to die for a month, and then the dog is brought back in for two more injections given 24 hours apart. This is what our vet recommended for Wren, because she was showing symptoms of a Stage Two infection. With the slow kill treatment, the dog must be kept calm for two months instead of one. However, it has a higher chance of killing all the worms in one go, and it is a little bit easier on the dog’s system.

Back when hills were difficult for her.

Wren was also put on an antibiotic to fight off any secondary infection, and a steroid to boost her system. Be forewarned–the steroid makes them very hungry, and also causes them to gulp water by the gallon. Even though Wren had a good grasp on potty training, her steroid caused her to have accidents. This is common, so don’t be surprised if your dog isn’t able to hold it. As soon as she was finished with her steroids, the accidents ceased.

Another common part of heartworm treatment is that the cough worsens, and they sometimes will hack up clear fluid. We also were surprised to find a little knob on Wren’s rump where her injections had been given, about a month after her last injection. Apparently that is also common, and it goes away after about a week! Symptoms of complications to watch out for are white gums, and extreme lethargy. If either of these crop up, call your vet immediately.

Wren on the run at last!

When the rest period is over, you can ease your pup into normal activity. Keep in mind that your dog was a couch potato for the last one to two months, so he/she is likely out of shape–let them guide the length and strenuousness of exercise. After two months of imposed rest, it was incredibly rewarding to watch Wren fly around outside. While she tired quickly at first, after a few weeks of regular exercise she soon kept up easily.

Her personality also emerged as she gained stamina–we learned that she’s obsessed with tennis balls, loves to go for long, daunting (to us–she’s three legged) swims, and that her favorite place to sleep is on the couch. Prior to her treatment, she didn’t have the energy to even get up on the couch!

While it was a long, not always easy journey, the joy we get from seeing how far Wren has come–and how much more she enjoys life with a fully functioning heart and lungs–has been worth every moment of worry and every penny spent.

Have a heart. Adopt a dog with heartworm disease.