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7 of the Most Common Dog Diseases
Most Common Dog Diseases by Stephanie N. Blahut
Medical content reviewed and updated by Janice Jones, a former veterinary technician. January 19, 2026
Dogs can develop a wide range of medical conditions throughout their lives, and some illnesses are seen more frequently in veterinary practices than others.
While no single list can cover every possible condition, understanding the mostcommonly diagnosed diseases can help dog owners recognize when something may be wrong.
This article provides an overview of several common dog diseases that owners may encounter, along with general symptoms and treatment considerations.
Each condition is summarized briefly to help readers identify when veterinary care may be needed.
Most Common Dog DiseasesThis page is not a complete medical reference. For a comprehensive, alphabetized guide to diseases and medical conditions that affect small breed dogs, visit our Small Dog Diseases Guide, which links to in-depth, condition-specific articles.
If you are looking for information on prevention, wellness care, or keeping your dog healthy at every stage of life, see our Small Dog Health Guide.
The conditions listed below are among the most frequently diagnosed dog diseases in veterinary settings. Not every dog will experience these illnesses, and outcomes are often improved with early recognition and prompt veterinary care.
Commonly Diagnosed Dog Diseases
Table of Contents
Parvovirus
Unfortunately, Parvovirus is a highly contagious and deadly viral disease. In fact, when this gastrointestinal illness is not treated, it has a mortality rate of more than 90%. Dogs younger than six months and that have not been vaccinated against this disease are at the highest risk for contracting parvo.
Symptoms
- Bloody diarrhea
- Vomiting
- Fever
- Weakness
Treatment
Because dogs with Parvo can get dehydrated from the vomiting and severe diarrhea that accompany this disease, they may require treatment with intravenous fluids.
In addition, the vet may prescribe anti-nausea medications as well as antibiotics to treat any secondary bacterial infections. Parvovirus still remains one of the most common dog diseases.
Pancreatitis
This condition occurs when a dog's pancreas becomes inflamed. Although the cause is not known, pancreatitis attacks often occur after a dog has eaten a fatty meal. Pancreatitis is a painful condition that can sometimes be fatal without treatment. Some small breeds — including schnauzers, Yorkshire terriers and wire fox terriers — seem to be especially prone to this illness.
Symptoms
- Vomiting
- Diarrhea
- Lethargy
- Abdominal pain (your dog may lie down with its rear end in the air and its front legs and head on the ground)
Treatment
Your vet can perform a blood test to determine if your dog has pancreatitis. Because dogs with pancreatitis can get dehydrated from vomiting or diarrhea, they often require intravenous fluids. Once your pet is well enough to go home, it will be placed on a strict, low-fat diet to prevent attacks.
Learn more about Pancreatitis in Dogs
Canine Influenza
Did you know that like humans, dogs can get the flu? It's true. Dogs have their version of influenza, which is highly contagious to other canines.
Canine influenza can be spread through coughing and barking as well as through ms contaminated with the virus. Humans who have come in contact with an infected canine can also pass the virus onto other dogs. So far, though, there has been no known transmission of the virus from dogs to humans.
Symptoms
- Coughing
- Discharge from the nose
- Fever
- Lethargy
- Trouble breathing
Treatment
Dogs with the flu should be isolated from other canines and kept as comfortable as possible during their recovery period. If your dog is running a high fever, your vet may prescribe an anti-inflammatory medication.
Giardia
If you have ever experienced a bout of Montezuma's revenge or traveler's diarrhea, then you are probably all too familiar with the microscopic protozoan giardia.
These one-celled parasites can be found in water, grass or soil that has been contaminated by the feces of an infected animal. If your dog has giardia, it may have ingested the parasite by drinking out of a contaminated creek or other body of water.
It can also get giardia by licking a body part that came in contact with contaminated soil.
Symptoms
- Vomiting
- Chronic intermittent diarrhea, sometimes bloody or frothy or with a foul odor
- Abdominal discomfort
- Gas
Treatment
Dogs who have tested positive for giardia will typically be given a drug such as fenbendazole or metronidazole. Your vet will want to follow up with your pet after several weeks to ensure that it is no longer infected with the parasite. You should also wash your dog, especially around its hind quarters, to rid its coat of any infectious giardia cysts.
Dilated Cardiomyopathy
Dilated cardiomyopathy (DCM) is a disease of a canine's heart muscle that results in an enlarged heart. Normally, this condition is seen in large dog breeds. Recently, veterinarians around the world have begun noticing a sharp rise in DCM cases in small breeds.
Although researchers are still trying to determine the cause, some suspect that this disease may be linked to the grain-free diet that many owners are feeding their dogs. However, the Food and Drug Administration has not yet recommended that owners stop feeding their pets grain-free dog food.
Symptoms
- Exercise intolerance
- Rapid breathing while your dog is resting or sleeping
- Coughing
- Distended stomach
Treatment
This is a serious condition that may need to be treated with several medications, including a diuretic and vasodilators.
Leptospirosis
Leptospirosis is a bacterial disease that can be spread to your dog through the urine of infected animals, including rats and wildlife. One of the main ways that canines can contract this disease is by drinking standing water — such as in a pond or a puddle — that has been contaminated with the bacteria.
Although some dogs may never exhibit any symptoms, others can become seriously ill. Because this illness infects a dog's kidneys, some canines can be left with permanent damage to these organs. Fortunately, Leptospirosis, one of the most common dog diseases can be prevented through vaccination.
Symptoms
- Fever
- Vomiting
- Increased thirst
- More frequent urination
- Organ failure
Treatment
Your veterinarian will typically prescribe antibiotics to treat leptospirosis. Your pet may require additional care for leptospirosis-associated issues, such as kidney damage.
Kennel Cough
If your dog has developed a chronic hacking cough, it probably has a highly contagious respiratory disease known as canine infectious tracheobronchitis.
This disease, commonly known as kennel cough, can be caused by several viruses and bacteria, including Bordetella. This disease is spread through direct contact with an infected canine or a contaminated surface, such as a water bowl.
Symptoms
- Dry cough, sometimes with a honking noise
- Lethargy
- Sneezing
- Low fever
Treatment
If your dog is diagnosed with kennel cough, your vet will probably recommend that you keep it quiet and allow it to rest for a week or two. Your pup may also be prescribed an antibiotic and cough medications.
Most Common Dog Diseases Pin for Future ReferenceSee Your Vet
Some serious diseases may seem relatively innocuous at first, but then spiral out of control. That's why it's critical to take your dog to the vet when it is not feeling well to help it receive timely and appropriate treatment. Any of the symptoms mentioned in this article could be associated with one of these most common dog diseases. Don't delay if you see anything unusual in your dog.
Most Common Dog Diseases: Author bio: Stephanie N. Blahut is Director of Digital Marketing and Technology for Figo Pet Insurance. Figo is committed to helping pets and their families enjoy their lives together by fusing innovative technology — the first-of-its-kind Figo Pet Cloud — and the industry’s best pet insurance plans.
More About Janice (author and voice behind this site)
Janice Jones has lived with dogs and cats for most of her life and worked as a veterinary technician for over a decade.
She has also been a small-breed dog breeder and rescue advocate and holds academic degrees in psychology, biology, nursing, and mental health counseling.
Her work focuses on helping dog owners make informed, responsible decisions rooted in experience, education, and compassion.
When not writing, reading, or researching dog-related topics, she likes to spend time with her six Shih Tzu dogs, her husband, and her family, as well as knitting and crocheting.
She is also the voice behind Miracle Shih Tzu and Smart-Knit-Crocheting
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