Lyme disease in dogs and cats


  • Lyme disease is an infection caused by a bacteria called Borrelia, which is carried by approximately 1.5% of ticks across the UK.
  • Borrelia can be transmitted to animals and humans via tick bites.
  • Lyme disease can affect multiple parts of the body and cause a variety of symptoms such as limping, stiffness, fever and low energy.
  • Lyme disease is rare, but much more common in dogs than cats.
  • Tick control is the best way to prevent Lyme disease in pets.

What is Lyme disease?

Lyme disease is a bacterial infection, transmitted by ticks. It’s also known as ‘Borreliosis’ because the bacteria that causes it is called ‘Borrelia’. Pets (and humans) are at risk of contracting Lyme disease if they are bitten by an infected tick that then stays on them for several hours to feed. Approximately 1.5% of ticks in the UK carry Borrelia. Borrelia bacteria initially multiply in the skin around the bite site, then spread throughout the body affecting the joints, and organs such as the kidneys, heart, and nervous system. Lyme disease tends to cause a variety of vague symptoms, which vary from pet to pet depending on where the bacteria spread. Lyme disease mostly affects dogs, people, and occasionally cats.

For more information on ticks and how to prevent them, read our articles:


Symptoms of Lyme disease tend to be vague, come and go, and vary from pet to pet. Symptoms include:

  • Limping and swollen joints – usually this starts in the joint closest to the tick-bite site, then shifts from leg to leg
  • Fever (high temperature)
  • Lethargy (low energy)
  • Swollen lymph nodes (glands)
  • Reduced appetite
  • Nerve problems
  • Drinking and weeing more
  • Pets don’t tend to get the classic ‘bulls eye/target’ lesion that humans get if bitten by a tick with Lyme disease

Lyme disease is very rare in cats, and if it does occur, symptoms tend to be very mild, and sometimes not even noticeable.


To make a diagnosis of Lyme disease, your vet will consider your pet’s symptoms, their history of tick exposure, and possibly run a blood test (but these aren’t always 100% accurate).



  • Most cases of Lyme disease can be successfully treated with antibiotics and improvements are usually seen within 24-48hours of starting them. The course is usually several weeks long, and should always be finished to make sure all bacteria are killed.

Anti-inflammatory pain relief

  • Anti-inflammatory pain relief can help with any inflammation and discomfort, such as joint pain.

Other treatments

  • If your pet has a severe case of Lyme disease, with more complicated symptoms, they may need to be hospitalised and given various medications to control their symptoms.
  • Unfortunately, if your pet doesn’t respond well to treatment, is in a lot of discomfort, and has a poor prognosis, it might be necessary to consider putting them to sleep.


  • Most pets with Lyme disease recover well with treatment, especially if they have mild symptoms.
  • However, it’s important to keep an eye out for any returning symptoms because relapses are possible.
  • Unfortunately, the outlook is much worse for dogs with severe symptoms or complications such as kidney failure.

Preventing Lyme disease

  • Use regular parasite control that covers for ticks.
  • Use a tick collar if you live in (or visit) a high-risk area.
  • Avoid long grass in the warmer months.
  • Avoid places known for ticks (find out if ticks are common in your area).
  • Regularly check your pet for ticks after walks and remove any you find - they are most common on the head, ears, armpits and belly.

When to contact your vet

If your pet is showing any signs of Lyme disease, book an appointment with your vet ASAP, especially if you have found a tick on them recently.

Find out whether you are eligible for free or low-cost PDSA veterinary treatment by visiting


Can people catch Lyme disease from pets?

No, people can only contract Lyme disease from tick bites. If you find a tick on yourself or have concerns, it’s best to contact your doctor or the NHS for advice

How do I remove a tick?

Check out our information and video on How to remove a tick from your dog or cat.


Published: August 2022

Written by vets and vet nurses. This advice is for UK pets only. Illustrations by Samantha Elmhurst.