In the winter months, it’s not just us humans who like to get cosy, in fact, rats also look for warm places to nest too.

Since some of the places they choose may sometimes be in our homes and gardens, it’s worth knowing what harm they can actually do to humans and pets.

The rodents are known for carrying diseases but how harmful are they?

What diseases are carried by rats?

Brown rats carry diseases such as leptospirosis or Weil's disease, salmonella, listeria, toxoplasma gondii and hantavirus, according to the British Pest Control Association (BPCA) website.

These diseases can be passed onto humans, usually by rat urine.

Rhyl Journal: Rats carry bacteria and viruses and pose a risk to both humans and dogsRats carry bacteria and viruses and pose a risk to both humans and dogs (Image: Getty Images)


The NHS website says you can get leptospirosis “if soil or freshwater (such as water from a river, canal or lake) that contains infected pee gets in your mouth, eyes or a cut, usually during activities like kayaking, outdoor swimming or fishing” or “you touch an infected animal's blood or flesh, usually from working with animals or animal parts”.

It adds that getting leptospirosis from pets, other people or bites is “very rare”.

Can rats be harmful to dogs?

The PDSA website explains that dogs can also get leptospirosis which is a disease that is caused by bacteria.

It is serious and often fatal for dogs. It can be caught from a number of things including from the urine of rodents – a dog who spends lots of time on a farm may come across this.

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Vets can vaccinate dogs against the types of leptospirosis found in the UK.

Symptoms of leptospirosis in dogs include a high temperature, jaundice (yellow gums and eyes), muscle pain and limping plus vomiting and more.

For more information on leptospirosis in dogs, you can visit the PDSA website.