These Are the Most Contagious Dog Diseases

Kennel cough is super contagious for other dogs and results from various bacteria and viruses. It's a type of bronchitis and can cause havoc in stressful social settings like dog shelters, where a dog's immune system may be compromised.

Dogs can be asymptomatic but infectious, an important factor in the spread of kennel cough at communal water bowls and parks. Eventually, you'll notice a runny nose and the signature hacking cough that spreads the condition. Your vet can tell you whether lil' buddy is a candidate for a kennel cough vaccine.

The good ol' flu will get your doggy too. The virus can survive for up to 48 hours on surfaces and 12 hours on hands and presents a lot like kennel cough or even coronavirus—it's often difficult to tell the difference where coughing and nasal secretions are concerned.

In otherwise healthy animals, flu symptoms will usually go away after a couple of days. Antibiotics can speed up recovery if symptoms persist.

Canine parvovirus, or CPV, has been an issue since 1978. It spreads quickly from dog to dog and is caused by a virus, not unlike the one that causes distemper in cats. Dog feces are the main culprit, and dogs who eat infected poop or come in contact with it will develop intestinal inflammation leading to vomiting and diarrhea.

Parvo is most common in unvaccinated dogs below the age of one, and Rottweilers and Doberman Pinschers have a higher fatality rate. Early treatment can improve a dog's prognosis, and vaccination is the best preventative.

Your dog could get infectious hepatitis due to canine adenovirus-1, which doesn't affect humans. Exposure is possible through direct contact with dog poop, urine, and saliva, as well as contaminated furniture, bedding, and utensils.

Hepatitis causes liver problems which can be fatal without aggressive fluid therapy. Look out for symptoms like a lack of appetite, fatigue, fever, conjunctivitis, vomiting, bloody stools, and cornea abnormalities called "blue eyes." Puppies are at an increased risk due to still-developing immune systems, but a vaccine at around two months old will offer protection.

Most people are familiar with rabies. We're warned about rabid dogs baring their teeth and snarling and are taught to give them a wide berth because their bite spreads the disease. But rabid dogs are sick dogs, first and foremost, and unfortunately, at death's door.

Once symptoms of the rabies virus, such as pica, seizures, or paralysis, take hold, recovery is unlikely. The rabies vaccine and boosters are mandatory in North America, and any suspected cases are to be put in quarantine.

Canine distemper is highly contagious because of airborne transmission and can be lethal because there's no cure. Symptoms are severe and may include runny eyes, gastric distress, paralysis, and seizures.

The distemper shot is suitable and recommended for every dog as a prophylactic measure—widespread vaccination means the disease isn't as common as it used to be.

Fungal infections often spread via contaminated soil. Depending on where you live in the U.S., you'll encounter different fungal infections, and droppings from bats and birds may spread histoplasmosis in particular.

Immunocompromised dogs have a higher risk of being affected. Ringworm is also a fungal infection, albeit not as troubling as one that causes pneumonia-like symptoms, for example.

External parasites like fleas are common and can be passed from dogs to other animals and owners. They're a schlep that will see you turning your home upside down, trying to rid your sanctuary of these pests. Your dog will be itchy and may self-mutilate to get relief, and scratching can lead to hair loss.

Thankfully, flea treatments are widely available, and you can chat with your vet about the best options and ongoing flea preventatives.

These parasitic worms live in, you guessed it, the heart—they get there by traveling through the bloodstream, and hundreds can reside in the chambers and pulmonary artery for up to seven years. Heartworms are spread by mosquitoes and cause difficulty breathing, among other symptoms. Treatments are often effective when administered timeously.

Do you live in a rural area? Your dog's more likely to get leptospirosis from the wildlife in your surroundings, and so, in turn, can you.

Dogs often contract this disease by drinking contaminated water containing urine from infected animals. Symptoms include muscle weakness, thirst, jaundice, irregular peeing, and abdominal pain.