Up until recently, most people would have been blissfully unaware of a rare group of viral diseases in mice and rats known as hantaviruses. The scary tale of the cruise ship MV Hondius however, where three passengers died after an outbreak, has left some concerned about whether their pet rat is in fact a risk to them.
It should be stressed that hantavirus infections are rare, and are often only associated with certain geographical areas where there is a higher risk of exposure – pet rats in the UK are not a concern! This article aims to give a brief overview of hantavirus, but also some of the aspects of pet rat ownership you might want to be aware of.
What are hantaviruses?
Hantaviruses are a group of viruses carried by mice, rats and other rodents. They are spread by droppings and urine, and infections in humans tends to happen in places were people and rodents live in close quarters. They cause disease symptoms from mild flu-like disease to severe respiratory illness. Most cases are seen in China and South Korea. The strain involved in the 2026 cruise ship outbreak was Andes hantavirus, one that is exceptionally rare, and only spreads between people when they are in very close contact for a long time (such as being on a cruise ship).
What is the risk of hantavirus in pet rats?
Whilst pet rats in the UK have sometimes been shown to have one strain of Hantavirus called Seoul Hantavirus, this strain has NOT been shown to transmit between humans. The Andes hantavirus has never been detected in the UK rodent population. The UKHSA states that the risk to the public in the UK is very low.
Why might you want to own a pet rat?
Rats can get a bad reputation when it comes to public health, but they are inquisitive, friendly and intelligent small mammals that can make wonderful pets for the right owner. They live for 2-3 years, and need to be kept with at least one other bonded rat to stay happy. They are easy to handle (especially if socialised from a young age), very rarely bite and can be great fun to watch with their busy curious nature. They need as much space as you can give them and lots of activities to do to stop them getting bored.
Rats are omnivores, like humans, and eat fruit and veg in addition to a complete rat food.
Rats do need lots of attention and playtime, becoming depressed without it, so if you’re short on time they may not be the best pet for you. They’re also most active in the evenings and at night, so make good pets for night owls but not so much for those that like their sleep!
What are the risks of owning a pet rat?
All rats, whether pet or wild, can carry bacteria and viruses that can cause diseases in people. These diseases are rare, but can be very serious if caught by someone with a weakened immune system. For this reason, rats are not good pets for:
- Very young children
- Elderly people
- Those with chronic health conditions like diabetes
- Pregnant people
- Those with a weak immune system from medications like chemotherapy or steroids, or those who have had their spleen removed
The risks to owners from rats come not just from bites but from contact with rat urine, droppings, saliva or bedding materials, whether touching it or breathing it in.
Diseases to be especially aware of in rats include:
Rat bite fever
This is a rare disease caused by the bacteria Streptobacillus moniliformis, something carried in the respiratory tract of apparently healthy mice and rats. It can be spread to humans not just in bites and scratches, but also from contacting urine. The bite itself usually heals well but the fever develops within 7 days, causing chills, severe muscle and joint pain, headaches, nausea and a rash. It is treated with antibiotics.
Leptospirosis
Leptospirosis is a bacterial disease that can infect all mammals, and there are many different strains. It is one of the diseases dogs are vaccinated against every year. Infected rats do not show any signs, but can spread the disease through their urine or water contaminated by it. In people disease ranges from a mild flu like disease to the very serious Weil’s Disease, which causes liver and kidney failure. It can be treated with antibiotics. That said, it is considered very rare in pet rats.
LCMV (lymphocytic choriomeningitis virus)
LCMV is carried by some rodents who are healthy for their entire lives whilst still shedding the virus. The biggest risk to humans is from house mice, but cases have been reported from pet rats. Most human cases present as a mild flu like illness, but in rare cases it can cause meningitis, and infection during pregnancy can infect the baby. It cannot be treated with antibiotics.
How can I keep rats safely?
As with any animal living in your home, the key to doing it safely is a matter of hygiene and common sense. Good hygiene, both in terms of direct contact and air spaces, can make all the difference between a healthy life together and a potential health hazard in your home. It also really helps with the smell – rats cannot be litter trained and like to wee a lot!
Here are some ways to keep your rats hygienically:
- Keep your cages clean and remove soiled bedding every day
- Deep clean the cage once a week
- Always wash your hands with soap and water for at least 20 seconds after handling your pet, their wee or poo or their bedding and toys
- Do not eat or drink around your pet rat, and do not let them share your food
- Never let your rat touch your face
- Cover any cuts or sores when handling or cleaning out
- Consider carefully where your rat’s cage goes in the house. It needs to be well ventilated, out of direct sunlight, away from rooms where food is prepared and eaten, and not in a bedroom.
- Don’t use the kitchen sink for cleaning out their cage, and if you must use the bathroom sink, make sure you clean and disinfect it afterwards. Ideally clean the cage outside, and consider wearing a dust mask
- Use wet wipes rather than sweeping or hoovering to clean as this reduces airborne spread of disease
- Make sure your pet rat doesn’t come into contact with wild rats
- Always supervise children when they are handling rats or cleaning them out
Conclusion
What happened on the MV Hondius is truly something out of a horror movie, but it came about due to a perfect storm of circumstances. UK pet rat owners do not need to be concerned about hantavirus spread to themselves beyond a general awareness that rats can carry some diseases that can spread to humans (but rarely between them). Rats can make wonderful pets when they are given the space, care and attention they need, and a good level of hygiene can ensure that they remain a safe pet to keep for many households.
References
What is hantavirus? How is it transmitted and what are the symptoms? – UK Health Security Agency
Reducing the risk of human infection from pet rodents – GOV.UK
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