Warning: These Cat Diseases Can Spread To Humans - Here's What To Watch For

Witnessing a pet become sick will almost always tug at the heartstrings of a pet parent. Most owners will go to any length to help when their cat is ill. However, this sometimes requires more tact and understanding of a pet's needs. The last thing anyone wants is to get sick themselves, making it harder to provide the best possible care. It may also have you wondering, can humans cat illnesses from their cats?

Not all common cat illnesses will cause concern, as not all can be passed on to their owner, such as distemper or feline immunodeficiency virus.  Yet, certain diseases can transfer from pet to parent. These are known as zoonotic diseases or zoonoses, and they are more prevalent than many may realize. The CDC notes that six out of ten infectious diseases in people can be spread via animals, while three out of four emerging diseases are zoonotic. While these rates may seem alarming, practicing proper hygiene and looking for symptoms can ensure pet parents can prepare and avoid unwanted infections from specific cat diseases. Here are some to watch out for.

Toxoplasmosis, or T. gondii, is a prevalent parasitic infection spread through various means, such as eating undercooked or contaminated food, ingesting feces, or inheriting it from their parents. The potential symptoms of toxoplasmosis in cats include lethargy, decreased appetite resulting in weight loss, fever, difficulty breathing, jaundice (noticeable in the yellowing of the skin), weakness, issues with coordination, seizures, and vision loss.

It is important to note that most cats don't show any signs. A broad estimate is that between 20% and 60% of cats are infected but don't show any symptoms. Many people are also silent carriers, with an estimated one out of three infected with the T. gondii parasite showing no signs. Toxoplasmosis becomes a concern for newborns, pregnant women, and those with autoimmune diseases. 

Owners should still practice caution despite the tendency for the infection to be asymptomatic, particularly for pregnant women whose newborns are most susceptible to neurological issues. Cleanliness is key; avoid litter if possible or use gloves, but change litter daily and wash hands thoroughly afterward. Drastic measures are luckily unnecessary; it is a common misconception that you must get rid of a pet cat once pregnant.

Influenza is a zoonotic disease due to its ability to mutate and transmit between different species. However, the rise of one troubling disease in house cats has led scientists to advise owners to take precautions: the influenza strain H5N1, better known as bird flu. As recently as March 15th, 2025, two cats in New York tested positive for H5N1 and were euthanized. This marks an alarming increase, with reports that as of the start of 2025, there have been over 50 cases of cats catching bird flu.

The symptoms of H5N1 in cats can include neurological issues (tremors, seizures, and uncontrolled movements), depression, excessive discharge from eyes, ears, and nose, and respiratory problems like coughing or wheezing. These symptoms are often fatal. Whether bird flu can pass between cats remains uncertain, and the chance of transmitting it to humans is low. Still, pet parents should be cautious when interacting with an infected cat and immediately contact their veterinarian when symptoms appear for subsequent advice on handling and reporting the disease.

Despite its name, ringworm is not a worm but a fungal infection, dermatophytosis. It appears on cats as irritated skin in a circular pattern that can be inflamed, scaly, red, or scratchy. Cats will also experience hair loss around the infected area. In rare cases, the condition can cause an infection around the nails. Ringworm is treatable but persistent, as a mix of oral and topical medication can last six weeks to several months. Most people have experienced a form of ringworm at some point, as it is more commonly known by the body part it infects, such as athlete's foot.

Ringworm is a potential concern in a multi-pet household, as it can spread from cat to dog and vice versa. An owner with ringworm can also spread it to their pets. The infection is treatable, yet it can be very persistent and requires cleanliness and separation of pets and family from the infected. For this reason, it is best to have any skin lesions checked by a veterinarian, have a new pet examined before being brought into the home, avoid stressors as this can result in a weakened immune system, and keep a cat on a regular and healthy routine. A feline should be able to recover from ringworm, but the hassle and potential vet bills make it a concerning condition.

Salmonellosis is an infection by the Salmonella spp. bacteria, which affects the intestines of mammals. Feline contact with salmonellosis comes from consuming raw meat or feces; a cat with pica (ingesting non-food items) and outdoor cats can make themselves more susceptible to picking up the bacteria. Most healthy cats will be asymptomatic, with their immune system able to handle the buildup of Salmonella spp.

However, if the bacteria spread too quickly, the initial symptoms can appear as diarrhea, which may contain blood, constipation with straining to poop, abdominal pain, and lethargy. If the bacteria spread throughout the system, known as systemic salmonellosis, it can manifest with other issues such as problems breathing, vomiting, and nasal discharge. Severe salmonellosis will require antibiotics and isolation of the pet while it is in recovery.

Pet parents can contract salmonellosis from contaminated pet food, handling a sick pet, or contact with an infected surface. The disease can also spread to other pets through the same means. Thankfully, chances of transmission can be reduced by properly washing hands after interacting with your cat and handling its toys or food. Regular changing of a cat's litter, followed by adequately washing hands, is also essential to prevent the spread of harmful bacteria.

Cat scratch disease, also known as cat scratch fever, is caused by Bartonella henselae, transmitted through scratches and fleas. Most felines won't show symptoms; 85% to 90% of those infected are benign and non-spreading. Kittens and cats with compromised immune systems may exhibit lethargy, lack of appetite, swollen lymph nodes, fever, vomiting, red eyes, and blisters or bumps. Prescribed antibiotics will usually lead to symptom relief within four to six weeks.

For people affected by cat scratch disease, the condition appears as a reddened and swollen skin infection from a non-healing cat scratch. This infection can be painful and result in flu-like symptoms. Antibiotics may treat the illness, but it will often pass without any intervention. Still, those with a compromised immune system can experience more severe reactions from cat scratch disease as the infection can spread to other areas of the body, like the heart and eyes. Cleaning any wounds and regularly clipping a cat's nails is the simplest way to combat the spread of cat scratch disease to their caretakers.

The spread of zoonotic diseases remains uncommon and should not cause owners to worry. Luckily, most of these problems are easily preventable through cleanliness and awareness of potential spreadable symptoms. "Better safe than sorry" is an old cliché, but with simple practices and care, pet parents can help ensure better health for themselves and their furry companions.

Always consult your veterinarian before making changes to your pet's diet, exercise, or care. To find an accredited veterinarian in your area, you can search the American Animal Hospital Association's online database.