Can Immunocompromised Individuals Keep Pets? — Infection Risks and Essential Safety Guidelines

ImmunityQ&AMeongsiljang Veterinary Advisory Board

Even people with weakened immune systems can safely enjoy pet ownership by following proper hygiene practices and staying up to date on vaccinations. Here’s a summary of key measures to prevent zoonotic diseases and ensure safe pet care.

Can Immunocompromised Individuals Keep Pets?

An immunocompromised person wearing a mask while petting their dog

Immunocompromised individuals are people whose immune systems are weakened compared to the general population, due to factors such as cancer treatment, organ transplantation, HIV infection, or the use of medications for autoimmune diseases. Keeping a pet is not contraindicated for these individuals. What truly matters is preventing zoonotic diseases—infections that can be transmitted between animals and humans. Both veterinary textbooks and guidelines from the U.S. Centers for Disease Control and Prevention (CDC) for immunocompromised individuals indicate that, with strict hygiene practices and regular health check-ups for pets, most people can safely live with their animals. At the same time, pet ownership carries the responsibility of safeguarding not only the animal’s health but also that of the owner and the broader community. However, during periods of significantly suppressed immunity, such as immediately after cancer treatment or in the early stages following hematopoietic stem cell transplantation, you must consult your attending physician before initiating any new contact with animals.

Why Is Pet Management More Important for Immunocompromised Individuals?

When the immune system weakens, microorganisms that are harmless to healthy individuals can cause infections. In states of compromised immunity—such as from the use of chemotherapy or immunosuppressive drugs, or due to bone marrow dysfunction—pathogens that would normally cause only mild issues can lead to more frequent and severe infections. Consequently, bacteria, fungi, and parasites that normally reside in a pet’s body can become sources of infection. Toxoplasma gondii, in particular, has been reported to cause serious disease and even death in immunocompromised individuals. Similarly, zoonotic intestinal pathogens like Salmonella and Campylobacter may result in only mild diarrhea in healthy people, but they carry the risk of progressing to severe, systemic infections in those with weakened immune systems.

Major Zoonotic Diseases and Transmission Routes

Item	Main transmission route	Key to prevention
Toxoplasmosis	Oocysts in cat feces	Pregnant women and immunocompromised individuals should not clean up feces
Salmonella/Campylobacter	Raw food diets and pet feces	Avoid raw food diets, wash hands
Reptile salmonella	Contact with turtles and lizards	Reptile keeping not recommended for immunocompromised individuals
Cat scratch disease (Bartonella)	Cat claws and saliva	Flea prevention, be careful not to get scratched
Ringworm (dermatophytosis)	Direct skin contact	Early treatment of pet skin abnormalities

Based on the U.S. Centers for Disease Control and Prevention (CDC) guidelines for immunocompromised individuals

Risk Levels by Pet Type

Not all animals pose the same level of risk. Generally, dogs and cats that receive proper preventive care, such as vaccinations and deworming, are considered low-risk. - Dogs: Maintaining routine vaccinations and deworming (especially for zoonotic parasites like roundworms) makes them relatively safe. - Cats: Keeping them indoors and managing their feces properly are key. - Reptiles and amphibians: They can carry bacteria such as Salmonella, so they are not recommended for individuals with weakened immune systems. - Rodents: They can serve as vectors for infectious diseases transmissible to humans, so caution is necessary when handling them. - Birds: There is a risk of zoonotic respiratory infections, so care should be taken. Always consult your physician before adopting a new pet.

An illustration comparing infection risks across different types of pets

Situations Requiring Immediate Veterinary or Medical Attention

If you experience any of the following symptoms, be sure to inform your doctor about your contact with your pet and seek medical attention: a persistent fever above 38°C, diarrhea or vomiting lasting more than 48 hours, bites or deep scratches from your pet, red skin spots that are enlarging, or fever accompanied by coughing or difficulty breathing. For individuals with compromised immune systems, infections can rapidly progress to sepsis. Even if symptoms resemble a common cold, always share your history of pet contact with your healthcare provider.

Essential Hygiene Practices for Daily Life

The key to caring for pets when you have a weakened immune system is maintaining consistent hygiene habits. - Handwashing: Wash your hands with soap for at least 30 seconds after handling your pet, touching food or supplies, or cleaning up feces. - Avoiding facial contact: Refrain from kissing your pet or allowing them to lick your face. - No raw diets: Avoid raw meat-based diets due to the high risk of Salmonella contamination. - Feces disposal: Whenever possible, have another family member clean the litter box. If you must do it yourself, wear disposable gloves and a mask.

Wash your hands after coming into contact with your pet.

Pet Health Care Is Caregiver Health Care

Keeping your pet healthy is the most effective way to protect immunocompromised caregivers. - Regular health checkups: Visit your veterinarian at least once or twice a year. - Vaccinations: Stay up to date on rabies and core vaccine schedules. - Deworming: Administer internal and external parasite preventatives consistently every month. - Fecal exams: Have your pet tested for parasites every six months. - Flea and tick prevention: This helps prevent vector-borne infections such as Bartonella. If you notice diarrhea, vomiting, or skin abnormalities in your pet, take them to the veterinary clinic immediately.

Special Precaution Periods During Cancer Treatment and Immediately After Transplantation

During chemotherapy for cancer, within 100 days after a hematopoietic stem cell transplant, or within six months after an organ transplant, your immune system is significantly compromised. During these periods, it is advisable to postpone adopting a new pet and to manage contact with your existing pets according to your physician’s guidance. It is safer to have other family members handle the cleanup of your pet’s feces, urine, saliva, and fur. If possible, consider keeping your pet in a separate room or restricting its access to your bedroom during this time.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

I am undergoing cancer treatment. Should I send the cat I've been raising to live with another family?

In most cases, there’s no need to worry. By consulting your veterinarian and following proper hygiene guidelines, you can continue living together comfortably. However, it’s best to have another family member handle the cat’s litter box, and avoid letting the cat lick your face or share your bed.

Which is safer for immunocompromised people, dogs or cats?

It’s hard to give a one-size-fits-all answer. Dogs have more opportunities to be exposed to external pathogens during walks, while cats face the risk of toxoplasmosis. However, by maintaining good indoor hygiene, scheduling regular check-ups, and keeping up with vaccinations, you can ensure a similar level of safety for both pets.

Is it safe for my pet to lick my face?

For people with weakened immune systems, it is important to prevent pets from licking their face, mouth, or any wounds. Their mouths may harbor bacteria such as Pasteurella and Campylobacter, which can lead to infections.

Is it okay to adopt a new pet?

It’s safest to adopt after your pet’s immune system has stabilized and you’ve received approval from your veterinarian. When adopting, choose an animal that is at least six months old and has completed a health checkup. It’s also recommended to avoid reptiles, amphibians, and exotic pets.

Are there any vaccinations that pets must receive besides rabies?

Dogs must receive the core combination vaccine (DHPPL) and kennel cough vaccine, while cats must receive the core combination vaccine (FVRCP). It is also important to administer monthly preventatives for fleas, ticks, and heartworm. Please consult your veterinarian to establish an appropriate vaccination schedule.

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References

[1] Tizard, I.R., Veterinary Immunology, 11th Edition, Elsevier, 2021

[2] CDC, Healthy Pets Healthy People - Immunocompromised Persons Guidelines, 2023

[3] Stull, J.W. et al., Reducing the risk of pet-associated zoonotic infections, CMAJ, 2015