Lyme Disease in Dogs

By: Amber Roberts

Is your dog suddenly sleepy or lethargic more often?
Photo by Kris, Yukon

Canine Lyme disease, a tick-borne illness caused by the bacteria Borrelia burgdorferi, is a concern for many dog owners. Lyme disease diagnoses have been on the rise since it was discovered, first in humans and later in dogs. Tick-related disease has refused to budge from news headlines lately, and you may be wondering if you are doing everything you can to protect your dogs and family from getting sick.

Prevention of Lyme Disease in Dogs

Even following every recommended precaution does not guarantee your dog will never be at risk, but exposure to tick-borne illness can be minimized by taking preventative measures year-round. Previous infection doesn’t create an immunity to Lyme disease; even if your dog has been treated for a past infection, he could become sick if bitten again. Lyme disease cannot be passed from a dog to other dogs or humans, but proximity to disease-carrying ticks can be assumed based on an infection.

Follow your veterinarian’s recommendations for vaccination and routine Lyme disease testing, and deter ticks by using flea and tick treatment year-round. Ticks are active whenever the temperature rises above freezing, so your dog may be at risk even in winter. Perform tick checks daily and after playing outdoors, in tall grass, or wooded areas, create a tick barrier around your property, and mow your grass regularly to keep ticks from taking up residence in your yard.

How Do Dogs Get Lyme Disease?

After a tick finds its way to a host, it will crawl around until it finds a suitable place to feed. The most common areas a tick will attach are in and around the dog’s ears, neck area, groin, or in his armpits. Transmission of Lyme disease occurs when an infected deer tick bites a dog or human and remains attached for 24-48 hours. The bacteria that causes Lyme disease won’t likely be transmitted unless the infected tick remains attached for the requisite amount of time. If you find a tick on your dog, removing it promptly may prevent him from contracting a tick-related illness.

Symptoms of Canine Lyme Disease

While a dog may have become infected with Lyme disease, only 5-10% will show clinical signs of illness. It is also possible for a dog to be infected and test positive without ever showing any symptoms. As the symptoms of Lyme disease typically occur between two and five months after a tick bite, you may not associate symptoms with Lyme disease. Further, the symptoms of Lyme disease in dogs differ from symptoms presented in humans.

Symptoms of Lyme disease in dogs include:

• Fever (103°-105°)
• Lethargy
• Loss of appetite
• Stiffness, limping, discomfort, or unexplained pain
• Swelling of joints or lymph nodes

Testing for Lyme Disease in Dogs

Your veterinarian may recommend a Lyme disease test if your dog begins to show symptoms, or even if your dog has been bitten by a tick but is not showing symptoms. There are two types of blood test that your veterinarian may use to screen your dog for infection. While a blood test may confirm an active or recent exposure to Lyme disease, both tests may present a false negative result depending on how recently your dog was bitten by a tick. Alternatively, a routine test may give a positive result without any clinical signs of illness as not every dog will show symptoms, and the test confirms both active or recently past infections—antibodies from a previous infection may be picked up on the test to cause a positive result. There has also been some concern that the Lyme vaccine may cause a positive result without an active infection. If your dog is showing symptoms of Lyme disease, your veterinarian may choose to treat him with or without a positive result.

If your dog is exhibiting symptoms of Lyme disease, your veterinarian will recommend a urine test. Occasionally, dogs may show high protein levels in their urine, which indicates a more serious condition and will require regular visits to the veterinarian for monitoring.

Canine Lyme Disease Treatment

As fewer than 10% of dogs ever show signs of illness even if they have contracted Lyme disease, your veterinarian will work with you to choose the best treatment option in the event of a positive blood test. Some veterinarians will treat every dog who tests positive, while others may only treat if symptoms appear.

Antibiotics are administered for several weeks to treat Lyme disease, though the symptoms tend to resolve within a few days of starting treatment. Antibiotic treatment is indicated for as long as your veterinarian recommends to prevent reinfection or a secondary infection. Your vet may prescribe anti-inflammatories to reduce joint discomfort and swelling, and may also recommend pain medication for your dog’s comfort.

Recovery and Prognosis for a Dog with Lyme Disease

Most dogs respond well to antibiotic treatment and recover within a short amount of time. Your veterinarian may want to perform a follow-up Lyme test, though the result may not be an accurate indication of recovery as the antibodies may alter the test results.

While rare, some dogs may develop long-term or life-threatening conditions related to Lyme disease. A small number of dogs may present minor, but continued, discomfort or develop more serious conditions such as kidney disease and loss of function in vital organs. Though not common, kidney issues related to Lyme require additional treatment because they may be fatal.
The prevalence of ticks and increase in Lyme disease diagnoses should not discourage you from spending time outside with your dog. Instead, take necessary precautions to protect your canine companions and yourself while you enjoy hiking, hunting, or just being outdoors.