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6 Common Dog Illnesses Every Dog Owner Should Know

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As dog owners, we never want to think about our pooch feeling under the weather, but it’s important to know the most common dog illnesses and how to spot potential symptoms.

Dogs are social creatures — and sometimes, they can also be dirty creatures. Eating whatever they find on the ground, getting in other dogs’ business, and licking anything in sight are not uncommon behaviors. And sometimes, these behaviors can lead to illness.

Keep in mind that not all illnesses are due to a lack of cleanliness. Sometimes, pups get sick for reasons we don’t understand — just like humans.

If you’re more aware of some of the most common dog illnesses, you may be quicker to notice symptoms and get your pup the help he needs.

6 Common Dog Illnesses

Dog diseases you should know.



Fleas are tiny insects that jump from one animal to another, causing itchiness and irritation. If left untreated, in extreme cases it can lead to serious illness. Even if your pup is the only domestic animal that roams your backyard, flea transmission from squirrels, rabbits, and other wild animals is still possible. 

Signs of fleas include itchiness, skin irritation, hair loss, and the presence of tiny specks on your dog’s fur and skin. If you notice any of these signs, take your pup to the vet immediately for treatment.

To prevent your pup from suffering from these itchy critters in the first place, you can either give your pooch an over-the-counter topical treatment or you should be able to get a prescription-only option from your vet. Your vet will be able to help you determine the best prevention.


Giardia is a parasitic virus that causes diarrhea, vomiting, and dehydration, and is transmitted through ingestion of contaminated feces. Whether your pooch got it from drinking contaminated water, picking up a stick with feces on it, or getting too close to other dogs’ business, giardia depletes your dog’s electrolytes and inhibits nutrient absorption. If your dog has diarrhea or unexplained weight loss, giardia might be the culprit.

Take your pup to the vet if you suspect giardia. If that is the case, your vet will be able to give your pup appropriate treatment. To prevent future cases of the illness, ensure that your pooch has access to fresh drinking water at all times so he won’t feel the need to take a sip from a puddle during his walk.


Heartworm is a small, thread-like parasite that lives in the heart and pulmonary arteries of an infected animal. Spread through mosquito bites, this illness is more common in hot, humid regions. If not caught early or treated properly, heartworm can lead to organ damage, lung disease, and heart failure.

Symptoms of heartworm include unexplained weight loss, extreme fatigue, coughing, labored breathing, and vomiting. If infected, your veterinarian will likely administer a series of vaccines that contain adulticides, then put your pup on preventative medication.

Getting your dog on preventative medication from the start is a much better option given the serious risks of heartworm and the involved treatment. Your veterinarian can likely prescribe a chewable pill for your pup that helps prevent heartworm. These are often prescribed to dogs younger than 6 months of age, and to older dogs once they are screened for the disease in advance.


Ringworm is a fungal infection that compromises a dog’s skin, hair, and nails. This illness is highly contagious to both animals and humans, but young puppies and immunocompromised dogs tend to be the most prone. 

Symptoms of ringworm include bald spots, patchy, crusted sections of skin, and skin lesions on a dog’s paws, head, and ears. Your vet will be able to diagnose the disease using an ultraviolet light or by taking a culture from an infected area. If ringworm is present, they may prescribe oral medication or specially formulated shampoo. Your vet can also give you instructions about how to avoid spreading the infection to other animals or people in your household.

Kennel Cough

Kennel Cough generally describes a group of bacterial or viral infections of the respiratory system. Similar to a chest cold or bronchitis in humans, the disease affects a dog’s windpipe and voice box. Two of the main causes of kennel cough are parainfluenza and Bordetella, and kennels will rarely board pups who haven’t been vaccinated for both illnesses. 

A dog can get kennel cough by coming into contact with contaminated nasal secretions, so it is spread very easily through objects, aerosols in the air, and direct contact with infected dogs. Symptoms of kennel cough are a dry cough, fever, gagging, nasal discharge, and coughing up phlegm. While the disease normally goes away on its own, it’s best to take your dog to the vet so they can advise about the best course of action. Oftentimes, they recommend getting a humidifier and may prescribe an antimicrobial or cough suppressant. To avoid kennel cough, discuss which vaccinations are appropriate with your vet.


Parvovirus is an illness that is acquired through exposure to contaminated feces and causes vomiting and diarrhea. This disease most commonly affects younger dogs and dogs that haven’t been vaccinated. 

Parvovirus often requires treatment through medications and intravenous fluids, but can become extremely fatal if left untreated. It is recommended that all puppies receive a series of vaccines between 6 and 16 weeks for parvovirus to avoid infection. 

Keep Your Pup Protected 

The good news is that most of these diseases are preventable with vaccinations, and if not, very treatable if caught early. In addition to talking to your vet about getting your pup all necessary vaccinations, we also recommend giving your pup preventative and proactive supplements to support a healthy and normal immune system. The more support you can give your pup, the happier you both will be.