Lyme disease is an infection caused by the bacterium Borrelia burgdorferi, a spirochete—a type of bacteria that is spiral in shape.

The main cause of Lyme disease is ticks, which can be found virtually anywhere in the United States, though practically all of the cases of Lyme disease were reported in the northeastern and north central regions as well as counties in northwestern California.

The Name Origin

Lyme disease is named after the town where an early outbreak of the disease was discovered and described: Lyme, Connecticut.

Cause of Lyme Disease

Ticks are the cause of Lyme disease in dogs and humans. Currently, three species of ticks are known to transmit the bacteria that causes Lyme disease:

  • the deer tick (Ixodes scapularis)
  • the western black-legged tick (Ixodes pacificus)
  • the Lone Star tick (Amblyoma americanum).

Other species of ticks may transmit the disease, but one of the above-named tick species is usually the culprit, especially the two Ixodes species.

Symptoms of Lyme Disease

One of the most common symptoms of Lyme disease in dogs is arthritis, or lameness and pain and swelling in the joints. Other symptoms are:

  • fever
  • dehydration
  • inactivity
  • lack of appetite
  • swollen lymph nodes.

Unfortunately, many of these symptoms are exhibited in other disorders and conditions in dogs, so Lyme disease may be misdiagnosed. Severe cases of Lyme disease may cause kidney failure or death.

Diagnosing and Treating Lyme Disease

A simple blood test is all you need to diagnose the disease in dogs, but the disease often takes weeks or months to develop. Some dogs will not test positive if the disease is in its early stages, which may be a reason that the disease gets misdiagnosed.

Antibiotics, such as tetracycline, are the main form of treatment for Lyme disease in dogs.

Preventing Lyme Disease

The best method of prevention is avoiding tick-infested areas, particularly fields and grassy areas. If that’s not possible, various chemical agents may be applied to prevent ticks from latching on to your dog. Certain pesticides may also be effective for your yard and safe for your dog.

Lyme disease vaccines are available for dogs, but the use of vaccines is controversial. Researchers are still testing the efficacy and safety of vaccines.

Despite your adherence to all these prevention methods, your dog may still get ticks, so checking your dog regularly for ticks and removing them immediately is important. The longer a tick stays on your dog, the greater the chance it has to pass on the bacteria.

Lyme Disease in Humans

Lyme disease may be transmitted to humans. Symptoms don’t usually appear immediately after infection: the incubation period can last three to thirty days before symptoms are exhibited.

In humans, Lyme disease is described in three different stages. In the first stage, people will often experience:

  • fatigue
  • fever
  • headache
  • joint pain
  • swollen lymph nodes
  • erythema migrans—a circular skin rash that grows.

The second stage begins weeks or months after the initial infection. During the second stage, bodily functions are affected and may include:

  • numbness and pain in the limbs
  • partial muscle paralysis
  • meningitis, resulting in fever and headache.

The third and final stage occurs weeks, months or even years after the initial infection. During this stage, people may experience:

  • chronic arthritis
  • memory loss
  • difficulty concentrating
  • chronic muscle pain.

See a doctor if you even suspect that you have Lyme disease.

Tick Removal

Look at our Dogs and Ticks article for step-by-step tick removal instructions.