8 deadly dog diseases

8 deadly dog diseases

Like most pet parents, I want and need my dog Henry to live forever. Even though he drives me crazy and ruined so much furniture and flooring over the years, I would be terrified if he came down with a deadly disease.

Dogs are like kids — they can get sick anywhere — and in order to keep them around as long as possible, it’s important to know which diseases are prevalent in dogs, what symptoms to look for, and how to prevent your pup from contracting them.

These eight dog diseases affect pups of all ages and breeds in every state. Because these diseases are so severe, I learned about most of them as I completed Henry’s adoption paperwork and during his first trip to the vet. Since dogs can catch these diseases at the dog park, groomer, or shelter, it’s important to always keep a watchful eye on your precious pup and call the vet if her behavior appears suspicious or she starts exhibiting any strange symptoms.

Canine distemper

Symptoms: runny eyes, fever, coughing, vomiting, paralysis

Canine distemper, sometimes called hardpad disease because it hardens dogs’ noses and footpads, is an extremely contagious viral disease that’s transmitted through airborne exposure or contact like shared food bowls. While all dogs are at risk of contracting canine distemper, it predominantly affects puppies and dogs that are especially prone to airborne viruses.

If you think your dog has distemper, take her to the vet. Although vets try their best to treat dogs with distemper by providing supportive care and preventing secondary infection by making sure they have plenty of rest and fluids, it’s often fatal. The best way to prevent your dog from getting it is by vaccinating her and keeping her from sick pups.

Canine parvovirus (parvo)

Symptoms: fever, lethargy, vomiting, diarrhea, dehydration, weight loss

Parvo is another highly contagious virus that infects dogs that come in contact with the fecal matter of a sick dog. And, sadly, parvo’s like gossip — easy to spread but hard to kill — once it attacks a dog’s internal organs.

Vets treat dogs with parvo by providing plenty of fluids, electrolytes, and secondary infection prevention, but it’s often fatal. The best way to keep your dog safe is by getting him vaccinated and keeping him away from all feces, especially infected feces.


Symptoms: lethargy, coughing, respiratory problems, heart disease, weight loss

Heartworms are disgusting little foot-long worms (parasites) that live in your dog’s heart, wreaking havoc on his heart, blood vessels, and lungs if he gets infected. Heartworm is spread by mosquitos and has been reported in all fifty states, not just places with dry climates. Buying preventative medication (like heartworm or flea and tick) is comparable to buying insurance — while you may not want to spend money on it now, it’s better than not being able to afford a crisis later.

If your dog has heartworm, expect a rigorous regimen of steroids, antibiotics, and an organic arsenic injection. The easiest (and cheapest) way to prevent her from contracting it is by taking preventative measures with annual blood tests and regular pills, topicals, or shots.


Symptoms: fever, pain, tingling or burning at the wound, hyperactivity

It’s the disease that took Old Yeller. (Well, a gun took Old Yeller, but his owner Travis had to shoot him because he contracted rabies.) It’s caused by the rabies virus, spread by a bite or saliva from an infected animal, and fatal once an animal gets it and starts showing symptoms. Due to its severity and that it’s easily spread to humans, many cities, states, parks, and groomers require dogs to have the vaccine.

There is no treatment for dogs once they contract rabies, and it is fatal. The best way to prevent it is getting her vaccinated and keeping her from rabid wildlife.

Lyme disease

Symptoms: pain, loss of appetite, fever, limping

This disease is caused by a bacterium that comes from tick bites (most commonly deer ticks) and once it’s in the blood stream, it spreads to the joints and causes pain for your pup. And if left untreated, lyme disease can be fatal.
Lyme disease can be treated with antibiotics and prevented by getting him vaccinated and checking his body for ticks after outdoor exposure.

Kennel cough

Symptoms: heavy coughing, gagging, lethargy

This disease is a highly contagious respiratory infection that causes inflammation and irritation of the airways. It’s called kennel cough because it’s a disease that can spread rapidly through animals in close proximity – like shelters, dog parks, boarding kennels, and doggy day cares – by direct contact with an infected animal, coughing, or sharing of contaminated bowls or blankets. While all dogs are at risk, puppies, unvaccinated, and older dogs are more likely to get kennel cough due to their weaker immune systems.

If your dog has kennel cough, your vet will prescribe antibiotics, cough suppressants, and plenty of rest. But when she’s home, keep a watchful eye on her — if she becomes listless or lethargic, take her back to the vet to make sure she doesn’t have pneumonia. You can help keep her from contracting kennel cough by getting her vaccinated (especially after you rescue her from a shelter) and keeping her away from sick dogs.


Symptoms: fever, muscle tenderness, lethargy, dehydration, vomiting, jaundice

This disease is caused by contact – either directly or through a sick dog – with Leptospira bacteria, which can be found in soil and natural water like streams, lakes, or rivers.

The American Veterinary Medical Foundation (AVMA) says dogs can also come in contact with the bacteria in infected urine, urine-contaminated food or bedding, a bite from a sick animal, and even the mother’s placenta.

Although vets can treat leptospirosis by providing antibiotics and supportive care, it’s easier to prevent by simply getting your dog vaccinated. If your dog ever comes in contact with the outside world, you should consider it.

Kidney disease

Symptoms: weight loss, increased urination and thirst, loss of appetite, vomiting

Dr. Roberta Relford, Chief Medical Officer of IDEXX Laboratories, says one in ten dogs will develop kidney disease: "Normally, healthy kidneys are able to eliminate protein wastes, balance body water, salts and acids to produce high quality urine. However, as dogs age, kidney disease can compromise these activities." And although kidney disease is more often seen in older dogs and cannot be reversed or cured, its progression and debilitation can be slowed as soon as it’s found and treated.

If your dog has kidney disease, your vet will prescribe medications and kidney-friendly diets, but the best way to prevent it is by catching it early. Regular vet checkups and appointments keep your dog’s health on track; vets can measure levels of creatinine in the blood and SDMA tests can be administered so irregularities can be more easily identified. Dr. Relford says, "The SDMA test is available to all veterinarians in the U.S. and Canada and picks up kidney disease months or even years earlier than traditional tests and is not impacted by a pet’s muscle mass."

Despite these doggy diseases, it’s imperative that you help your dog stay healthy by keeping her active and maintaining regular visits to the vet. I remember bringing three month old Henry home like it was yesterday and now he’s almost three years old. He is still as spry and active as ever, but I know those days won’t last forever so I am cherishing and prolonging them while I can by watching his weight, taking him on walks and runs, and making sure he sees the vet more often than he prefers.

Image: Maria Eklind