Can You and Your Dog Both Be Sick? | Shared Illness Truth

You wake up with a scratchy throat and low energy. Your dog, usually bouncing at the door, stays curled in bed. It’s easy to assume you caught the same bug overnight. But the truth about shared sickness between people and pets is more specific than that.

The honest answer is yes—sometimes you can pass an illness to each other. But the common cold and flu are almost never the culprit. Instead, the shared sicknesses that do occur involve bacteria, parasites, or fungi that are known to jump between species. This article covers which illnesses can actually transfer, which ones cannot, and what to do if you suspect you and your dog are both under the weather.

How Shared Sickness Happens

Cross-species illness falls into two categories. Zoonotic diseases are infections that spread from animals to humans. Reverse zoonoses, also called anthroponoses, go the other way—from humans to animals. Both are caused by germs like bacteria, viruses, parasites, and fungi that can survive in more than one host.

Transmission often happens through direct contact—saliva from a bite or lick, contact with infected feces or urine, or breathing in contaminated aerosols. Dogs that sleep in your bed, share your food, or give face kisses are at slightly higher risk of catching something from you, and vice versa.

The key point: the illness must be capable of surviving in both species. Many pathogens are very picky about their host, which is why the list of truly shared illnesses is relatively short.

Why The Common Cold Isn’t Shared

When you and your dog feel sick at the same time, the first assumption is often the cold or flu. But these viruses are highly species-specific. The rhinoviruses that cause human colds cannot replicate in dog cells, and the kennel cough virus (Bordetella bronchiseptica) is not commonly classified as a zoonotic infection. Research from major medical institutions confirms that dog-to-human transmission of cold and flu viruses is not a documented pathway.

• Cold and flu species-specific: Human cold and flu viruses are adapted to human respiratory cells and do not infect dogs. Likewise, canine influenza and parainfluenza do not infect people.
• Dog bite infection risk: While you cannot catch a cold from a dog, a bite or scratch can introduce bacteria like Capnocytophaga or Pasteurella into your bloodstream, causing serious illness.
• Salmonella shared symptoms: Both humans and dogs infected with Salmonella experience nausea, vomiting, diarrhea, fever, and abdominal cramps. It can pass through contaminated food or feces.
• Giardiasis: This protozoan parasite causes diarrhea, gas, and stomach cramps in both species. Transmission is possible through contaminated water or from your dog’s stool.
• Toxocariasis: Caused by a dog roundworm shed in feces, this infection can cause fever, coughing, eye problems, and liver enlargement in humans, especially children.

The important takeaway: if you have classic cold symptoms and your dog has a runny nose or cough, it’s almost certainly two separate bugs—not the same one.

When Humans Spread Illness To Their Dogs

Reverse zoonoses are gaining more attention. Per the University of Florida’s guide on reverse zoonoses explained, pets that share beds, kisses, and dining areas are at measurable risk of catching infections from their owners. The same study notes this phenomenon is more common than once believed, though still relatively rare overall.

Diseases that can pass from humans to dogs include certain strains of MRSA, tuberculosis, and some fungal infections like ringworm. Even the flu—while species-specific for human strains—has been reported in dogs exposed to pandemic H1N1, likely through very close contact. However, seasonal flu viruses rarely establish in dogs.

If you are sick with a contagious illness, it may be wise to limit close snuggling and avoid sharing food or water bowls until you recover. Your dog’s immune system might not recognize the same germ the way yours does.

Not every illness on this list is common, but it shows that the possibility of sharing a sickness—while rare—is real and backed by veterinary and medical research.

Signs Your Dog May Have a Shared Illness

It can be hard to tell if your dog’s symptoms match something transmissible. Look for patterns that align with known zoonotic or reverse zoonotic diseases.

1. Persistent diarrhea: If your dog has acute, chronic, or intermittent diarrhea, giardiasis is a common suspect. The same goes for Salmonella. A veterinarian can run a fecal test.
2. Fever and lethargy: A dog with plague or salmonellosis may show fever, low appetite, and apathy. Swollen lymph nodes are another red flag for plague in dogs.
3. Skin lesions or hair loss: Ringworm causes circular, scaly patches. If you or your family have similar spots, cross-species infection is possible.
4. Vomiting and weight loss: Toxocariasis can cause vomiting and poor growth in puppies. In humans, it can lead to eye inflammation.

If you notice any of these signs alongside your own symptoms, it is wise to keep some distance and consult a veterinarian. Do not assume you both have the same thing—let tests provide the answer.

How To Protect Yourself And Your Pet

Preventing the spread of illness requires simple, consistent habits. The CDC’s zoonotic diseases definition resource emphasizes handwashing as the first line of defense after handling pets, their food, and their waste. Keeping your dog up-to-date on veterinary care and vaccinations is equally important.

If someone in the household is sick—especially with a fever, diarrhea, or skin infection—avoid letting your dog lick faces, share food, or sleep in the same bed until you recover. For dogs with diarrhea, pick up waste immediately and wash your hands thoroughly. Good hygiene reduces the risk for everyone.

Routine vet checkups also help. A dog that is healthy and vaccinated is less likely to harbor pathogens that could make you sick. Likewise, keeping your own vaccines current—like tetanus and flu shots—protects both of you.

The Bottom Line

You and your dog can both be sick at the same time, but sharing the exact illness is uncommon and usually involves bacteria or parasites rather than viruses. Cold and flu are species-specific, so don’t blame Fido for that sniffle. If you notice matching symptoms like diarrhea, fever, or skin issues, a veterinarian and your doctor can work together to identify the cause.

If your dog develops diarrhea that lasts more than a day or two, especially if you have similar symptoms, a veterinarian can perform a fecal float or other tests to rule out giardiasis or Salmonella—and they can advise whether you need to see your own doctor for treatment as well.