What is Lyme Disease in Cats and Dogs?

Most dogs exposed to the bacteria that cause Lyme disease do not show signs of illness. When clinical disease occurs, signs may include: 

• Lameness that may come and go or affect different legs

• Swollen, painful joints

• Fever

• Reduced appetite

• Tiredness or reluctance to exercise

• Enlarged lymph nodes (glands)

A serious kidney condition has been reported in some dogs with antibodies to these bacteria, although the relationship is not fully understood. Signs of kidney problems may include increased thirst and urination, vomiting, reduced appetite and weight loss. 

These symptoms can have many other causes, so they do not necessarily mean your dog has Lyme disease. 

Contact your veterinary practice if your dog develops unexplained lameness, swollen joints, reduced appetite or unusual tiredness. Tell your vet if you have found a tick on your dog or recently visited an area where ticks are present, including travel abroad. 

You may not have noticed a tick bite, so do not wait to seek advice if your dog is unwell. 

Seek veterinary advice promptly if your dog is vomiting, drinking or urinating more than usual, or becoming increasingly weak. These signs can have many causes and need veterinary assessment. 

Your vet will assess your dog’s symptoms, examine them and ask about possible tick exposure, including where they walk and any travel abroad. 

Blood tests can check for antibodies to the bacteria that cause Lyme disease. A positive result can indicate exposure to the bacteria but does not prove that they are causing your dog’s symptoms. Your vet will interpret the result alongside the type of test used and any history of Lyme vaccination. 

Antibodies take time to develop, so testing shortly after infection can give a negative result. 

Your vet may recommend other blood and urine tests to assess your dog’s general health, check for kidney problems and investigate other possible causes of their symptoms. 

Diagnosis involves considering these findings together and ruling out other conditions. 

Dogs with suspected clinical Lyme disease are usually treated with a course of antibiotics lasting around four weeks. Your vet may also prescribe pain relief for sore joints. 

Dogs with joint signs often improve within a few days of starting treatment. However, improvement with antibiotics does not, on its own, confirm Lyme disease. If your dog does not improve, your vet will reassess them and investigate other possible causes of their symptoms. 

Dogs with kidney problems may need additional treatment, including hospitalisation, depending on the severity of their illness. 

A positive antibody test alone does not necessarily mean your dog needs antibiotics. Your vet will consider their symptoms and other test results before recommending treatment. 

Reducing your dog’s exposure to ticks can help reduce the risk of Lyme disease. Your veterinary team can recommend suitable tick prevention based on your dog’s lifestyle, where they walk and any travel plans. Tick prevention reduces risk but cannot guarantee protection. 

Check your dog for ticks after walks, particularly after visiting woodland, long grass or areas with wildlife. Pay attention to the head, ears, neck, legs and between the toes, although ticks can attach anywhere. 

Remove attached ticks promptly using a purpose-designed tick-removal tool, following its instructions. Avoid squeezing the tick’s body or applying substances such as oil or alcohol. If you are unsure how to remove a tick, ask your veterinary team for help. 

Dogs with joint signs attributed to Lyme disease usually respond well to antibiotic treatment. If symptoms persist or return, your vet will reassess your dog and consider other possible causes. 

Dogs with suspected Lyme-associated kidney disease can be seriously ill, and the outlook may be poor. Some dogs may need ongoing treatment and monitoring. 

Previous exposure does not protect your dog from becoming infected again, so appropriate tick prevention remains important.