References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
No, you cannot catch STIs from dogs, cats or other pets. STIs are species-specific infections that need particular human cells to survive and reproduce. The bacteria and viruses that cause human STIs cannot infect animals, and vice versa. Pets carry their own infections, some of which can affect humans, but these are not STIs.
Here’s a clear explanation.
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Why STIs Don’t Cross Species
- STI pathogens evolved to live in humans specifically
- They need human immune cells, tissues or mucous membranes to survive
- Animal cells are biologically different enough that human STIs can’t establish infection
- Many pet infections don’t exist in humans and vice versa
Common STIs Are Human-Only
| STI | Can Pets Catch or Spread It? |
|---|---|
| HIV | No — human-only |
| Chlamydia (trachomatis) | No — human-only; pets have a different chlamydia species |
| Gonorrhoea | No — human-only |
| Syphilis | No — human-only |
| Herpes (HSV) | No — human-only |
| HPV | No — human-specific types |
| Hepatitis B | No — human-only |
Pet-Related Infections That Aren’t STIs
Pets can transmit certain diseases to humans, but these aren’t sexually transmitted:
- Toxoplasmosis — from cat faeces; important in pregnancy
- Ringworm — fungal skin infection
- Cat scratch disease — from cat scratches
- Salmonella — from reptiles, raw pet food
- Rabies — very rare in UK; from bites
- Fleas and ticks — can bite humans and sometimes carry disease
These are zoonotic infections — diseases that can pass from animals to humans — but not through sexual contact.
What About Bestiality?
Sexual contact with animals (bestiality) is illegal in the UK and carries health risks including bacterial infections, parasitic infections and injury. But it does not transmit the common human STIs like HIV, chlamydia or gonorrhoea, because these require human cells to replicate.
Pet Hygiene and Your Health
- Wash hands after handling pets, especially before eating
- Clean litter trays and cages regularly
- Keep pet vaccinations up to date
- Watch for signs of illness in pets and visit the vet when needed
- Pregnant women should take extra care with cat litter (toxoplasmosis risk)
Common Myths
- “You can get HIV from a cat bite” — no
- “Dogs carry chlamydia” — they have a different species that doesn’t cause STIs in humans
- “Letting a pet lick you can transmit STIs” — no
- “My cat gave me an STI” — not possible
Read more: How you can’t get HIV | Mosquitoes and STIs | What is HIV?
Frequently Asked Questions
Can I catch HIV from my pet?
No. HIV is a human-only virus that cannot infect dogs, cats or other pets.
Do pets carry chlamydia?
Some animals have their own chlamydia species (like Chlamydia felis in cats), but these don’t cause STIs in humans.
Can I get worms or parasites from my pet?
Yes, some parasites can pass from pets to humans (toxocara, giardia). These aren’t STIs but are good reasons for pet hygiene and regular veterinary care.
Related reading
- Blood Test for Syphilis, Hepatitis B and Hepatitis C
- Can You Get an STI From Being Fingered?
- Can You Catch an STI From a Toilet Seat?
- Can You Clear HPV Once You Have It?
- Can You Die From Hepatitis B?
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
