Four diseases common to dogs, a series, hookworms

Four Diseases You Need To Know About To Keep Your Dog Healthy- One Is Heartworms

There are four infectious diseases that are common amongst dogs. Knowing about them and what to look for is something you should do to help keep your dog healthy. The four common infections are: Heartworm, Giardia, Distemper, and Parvo. I am writing a series of articles about these four. But each article will focus on only one of the infections, today’s topic – Heartworms.


Heartworms (Dirofilaria immitis) are long white worms that actually grow inside of the heart muscle itself. They are similar to Roundworms and can severely mess up the blood vessels of your dog, which can lead to not only heart issues, but also lung issues. They were first identified in 1856, when they occurred mostly in coastal towns in the United States. Since then, they have spread to every area within the United States.

The carrier of the heartworm is the mosquitoes. Just like they carry the bird flu for humans, they carry these parasitic heartworms for dogs. They are transferred from mosquito to dog through the process of the mosquito sucking blood from its victim. As the mosquito sucks, it also pushes into the bitten area a sort of topical sedative through saliva that lubricates as well as hides the detection of the mosquito feeding. That saliva carries all sorts of goodies, but the most concerning one for your dog is the heartworm larvae.

An infected dog with heartworms gets bitten by a mosquito. The heartworms have released their young, the larvae, into the bloodstream of the infected animal. The larvae are then sucked up with the blood the mosquito is feeding upon. Later to be transferred into another dog through the saliva of the mosquito biting the next dog.

The worms can feed slowly off from their victims, and can live inside the heart muscle as many as 5 to 7 years before they kill their victim. The larvae do not live quite as long, but they can exists for up to 2 years as a larvae before they find a home in a victim’s heart to become the worm. The time it takes for a larva to settle in a heart, grow to a worm, mate and release more larvae is approximately 6 to 7 months from the time the larvae enter their victim.

Dogs are not the only victims; Heartworms can be found in cats, ferrets, squirrels, bears, and even sea lions. By the time a dog shows almost all the symptoms, the worms could be several hundred in numbers spread throughout the heart, vessels, and the lungs. These worms can be up to 14 inches in length.

Heartworms kill their victim by eventually becoming so large they block different chambers of the heart and various large blood vessels. This slowly restricts the flow of blood to the rest of the body. When a worm dies, their body flows naturally through the large vessels to the next organ, the lung. When enough die, their bodies can block the blood flow off from the lungs completely. In severe cases of heartworms, they block a large vein called the vena cava. When this vein is blocked, the blood backs up into the liver. The liver then becomes filled with blood, oversized and severely damaged.

Signs Of Heartworms

An infected dog will start to show flu-like symptoms. They have a continued decrease in appetite. They start to lose weight and generally are slow to move and appear tired all the time. Many times you will notice this all start with a cough. In some cased the abdomen will accumulate fluid, making the dog look like they have a pot belly.

If your dog is starting to show some of these symptoms, do not hesitate to take the dog to your vet. The vet will perform some blood tests and take x-rays. Many blood tests are available, but the best one is a Serologic test. This test actually looks for certain antibodies, which are proteins that the body makes to fight off the worms. However, the test is not fool proof, and there have been many reports of the test falsely identifying an infection. Your vet will not more than likely make a call on a single test, and knows what to do.

Preventing Heartworms

The best way to prevent heartworms is a 3-step process which includes: preventative medication/application, performing routine heartworm testing through your vet, and limiting the animal’s exposure to the carrier, the mosquito.

Since all you have to do is bring the animal to your vet for testing, and keeping your dog from mosquitoes is self explanatory, we will focus the prevention section of this article on the different medications and applications you can purchase to protect your dog. There are several on the market to choose from, and you can purchase them through your vet or through other pet supply stores, even online the Internet.

The first thing to understand is that it is a preventive procedure. That means you are trying to prevent the infection, which would indicate attacking the larvae. The products do just that, attack only the larvae. If your dog has adult worms, these products will not help. The adults have to be killed with special adult killing drugs. These are usually discussed with you by your vet in their discussion of treatment if the vet identifies positively that your dog is infected.

Even though these are considered a preventive, it is really is an after treatment. Most all of these products kill the larvae that have been accumulating in your dog or other pet for the last 30 days. They would not kill the larvae introduced to your animal two days from treatment by another mosquito bite. That is why most treatments are ongoing every month.

There are too many products with too many active ingredients to talk about in this article. There are common things and individual things related to each treatment as well. Some are topical that you apply to the skin, most are in the form of a pill. A lot of these will do more than kill Heartworm larvae, such as also control Hookworms, Roundworms, Tapeworms, and Whipworms. While others also control ticks, fleas, mites, other small parasites, and even control certain types of mange.

There is no single product that does it all. You have to get to know your product well enough to know how to properly apply it and what it will and won’t do for the dog. If you have problems with getting your dog to take a pill, maybe a topical is the solution. However the pills mostly affect all types of worms, but not the fleas, ticks, and other external parasites. The topicals affect most external parasites, but not the rest of the types of worms. They all affect the Heartworm larvae.

One important thing to note, if you switch from one type of preventive to another, you should let your vet know this. In addition, the vet should be doing an additional Heartworm test when you do switch preventives.

A fully infected dog may or may not survive treatment. In some cases, if caught in time, Heartworm adults can be treated and killed, while you start treating the larvae. In severe cases, Heartworms may be removed surgically from the heart and lungs, and if caught in time, follow up with treatment of killing the adult worms and larvae.

There are times, however, that the worms win. In that time, you have to decide what to do. Keep the dog living in its weakened state until eventual full blockage or heart failure, then death. Or take your dog to the vet to be put down. Neither are a pleasant experience, and either way you will more than likely be heartbroken.

I know that this article has been long, but next to cancer, this is one of the most dreaded dog diseases. Its physical affects on the dog is heart wrenching to watch. And watching your beloved pet die a slow and painful death takes a toll on you as well, both emotional and physically. So I thought it important to make you fully understand this thing called the Heartworm. I am sure you will forgive the length of this article because it is one of the most informative articles I have written. If you have ever experienced a dog going through this, I know you appreciate my efforts here.