The 7 Worst Dog Illnesses You Can Protect Your Dog From

April 14, 2025 Napa 'ze Dog

Dog illnesses are one of the not-so-fun parts of being a dog owner.

Communication is limited, and at times you may feel helpless in trying to console your pup. Allergies, food, parasites, and even everyday germs can make dogs sick. Didn’t anyone ever tell you to never jump down the google diagnosis rabbit hole? PetMD has a complete list of dog illnesses and while reading it can be scary, try not worry because a lot of them are preventable.

We’re going to talk about seven dog illnesses and ways you can prevent them. Just be advised that I am a dog, not a doctor and you should always seek the professional advice of your veterinarian when you are worried or think your pet is ill.

1. Lyme Disease

Symptoms of lyme disease include depression, swelling of the lymph nodes, loss of appetite and fever, as well as lameness and swollen, painful joints according to PetMD. These are all uncomfortable symptoms of a bacterial infection most commonly caused by the deer tick, not the dog tick.

It’s essential to check your dog when you bring them in from outside. You can buy one of the best tools to remove ticks for under ten dollars, and it’s one of the best investments my pal Hazel’s owners have ever made. They live in the woods of Massachusetts which is a common breeding ground for these disgusting creatures. They use the spoon-shaped tool many times in a week, and combined with flea and tick medicine; they’re able to keep Hazel healthy and happy.

The only good thing is that Lyme disease is easily preventable with flea and tick medications, and you can even limit their exposure with some tips from the CDC.

2. Heartworm

Heartworm is another terrible illness that affects over a million dogs in the US according to the American Heartworm Society . As awful as heart worm is, it’s treatable and even preventable when you administer medications such as Heartguard to your pet. If ignored, this is one of the dog illnesses that can be fatal. Your vet will test your dog at their check-ups, so it’s always important to bring your dog to their regular yearly wellness exams.

3. Death by Chocolate

Chocolate poisoning is one of many preventable dog illnesses you don’t want to have to experience. Seriously, chocolate is no joke. It can cause vomiting, diarrhea, seizures and even death. You can prevent this by being vigilant about where you store foods.

Some dogs are magicians like my old friend Stanley. He was a slow-moving Basset Hound that would somehow steal his owner’s candy from off their high countertop. The only way to stop him was to keep their treats in their fridge or high-up cabinets. Luckily, he never got sick, but not all dogs are that lucky.

4. Parvovirus

Parvovirus, commonly known as Parvo, is a viral illness that attacks a dog’s heart and intestines. Vaccines are given to puppies to prevent this, so it’s not as common as some dog illnesses. However, breeding facilities and shelters are known to deal with Parvo because of the higher chance of coming into contact with affected dogs.

The sad part is more than half of the dogs diagnosed with Parvo will die, Please make sure to vaccinate your dog. Vaccines not only keep your dog safe but others as well.

5. Distemper

Distemper is an airborne virus that starts off with cold-like symptoms but can quickly escalate and even cause brain damage. If a dog survives this illness, it can take weeks. It can also lay dormant and present itself again turning into a recurring nightmare for you and your dog.

The best way to prevent distemper to make sure your dog is up to date on its vaccines. Trust me when I say that this is not something you ever want to experience. I already said it, but I’ll repeat it. Make sure your dog is up to date on its vaccines to prevent unnecessary dog illnesses!

6. Rabies

When you think of rabies, you usually think of a wild animal such as a skunk, raccoon or opossum, but if you’re not careful your dog could get rabies too. Another dog illness prevented by vaccines, but also indefinitely lethal if contracted.

Rabies is another reason to stay on top of regular dog visits. If you miss a vaccine and there is an incident between your dog and a critter in your backyard you could be sorry.

7. Leptospirosis

How’s that for a tongue twister? Leptospirosis may be fun to say, but it’s not a good time for your dog. Stagnant water and contact with infected urine from animals can pose a significant threat.

Liver and kidney, central nervous system and reproduction functions are all at risk for causing irreversible, and even fatal damage. It’s important to vaccinate if you think your dog is at risk. Not all vets will automatically administer this vaccine, so it’s a good idea to ask if yours does.

Notice the trend here? Besides chocolate poisoning, I think it’s safe to say that regular visits to your vet, combined with vaccinations can help your dog live a long and healthy life.

Do you have any experience with any of these dog illnesses? Share your story in the comments.

Side note: Do you run a business in the pet industry? Would you like to drive more traffic and sales to your site through a search-optimized pet blog? Get in touch with my office-mates at Lantern Content Marketing!

About Napa 'ze Dog

My name is Napa and I'm the Lantern Content Marketing Adventure Company office dog. They create content for business blogs, so I do my part by blogging about pet stuff. My favorite topic is poop! Since you asked, I'm an F2B Miniature Goldendoodle. Everything else you want to know about me is right over here!

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