Lyme Disease in Dogs
What is Lyme disease?
Lyme disease is an infection caused by the bacterial Borrelia Burgdorferi. It is transmitted by the deer tick (Ixodes). The ixodes tick nymph is passed to your dog by small mammal carriers where it feeds on your dog and transfers the borrelia organism to your dog. The adult stage ixodes tick lives on deer, raccoons, and dogs.
Lyme disease was first recognized in humans in the area of Lyme, Connecticut. The infection has since become more and more prevalent especially along the northeastern and eastern regions of the U.S.
What are the signs of Lyme disease in dogs?
Silent infections with no signs of illness may be the most common form of Lyme infection in dogs.
Lameness, fever, painful or swollen joints, loss of appetite, weight loss, kidney failure are all possible symptoms in infected dogs.
Other rare symptoms may occur if the infection affects the heart, brain or other organs
What tests are done to diagnose Lyme disease in dogs?
4DX test - this is a quick screening test done at the hospital. It will screen for exposure to Lyme, as well as Anaplasma and Ehrlichia both of which are transmitted by ticks. It will also screen for heartworm disease which is transmitted by mosquitos. This is a + or - test but does not give a titer level.
Lyme C6 titer - this is a titer level to the C6 protein from the surface of the borrelia organism. This test differentiates those dogs whose infections need to be treated from those whose titers are so low that they are clinically insignificant. Titers above 30 are considered to be significant and dogs with titers above 30 should be treated even if no clinical symptoms are apparent. Titers do not become elevated immediately after tick bites. It may take 2 to 3 months for the titer to rise. Titers do not drop immediately after treatment.
Urinalysis - this is a urine test to evaluate your dog for possible kidney failure if the C6 titer is above 30. We look for evidence of infection, inflammation, and protein loss in the urine.
Urine ERD or UPCR - these are two different tests which can help to quantitate the amount of protein in the urine. Protein loss in the urine is an indication that the borrelia infection may be causing damage to the kidneys. Kidney damage may not be reversible and thus carries a more guarded prognosis.
Can Lyme disease be treated?
Treatment for Lyme disease is recommended for any dog with a C6 titer over 30 or if symptoms are present and the 4DX test is positive. If your dog does not respond to treatment then other diseases may also be present.
In most cases the treatment for Lyme disease is doxycycline, an antibiotic. The treatment is usually for 30 days but some dogs may need to be treated longer or retreated in the future. The borrelia organism is not expected to be completely eliminated by antibiotic treatment, but to be decreased to a controlled level. Dogs that are infected are considered infected for life and can have a recurrence of symptoms in the future. Other treatments may be recommended if your dog has protein in the urine or neurological or cardiac symptoms.
What happens after treatment?
After your dog is treated for Lyme disease you should consider vaccination against the borrelia organism. The recombinant vaccine for Lyme disease is 80-85% effective and safe for most dogs. It will not protect against infection from Anaplasma, Rocky Mountain Spotted Fever or Ehrlichia for which there is no vaccine. Being infected will not provide immunity to future infection. Remember that your dog's environment still carries the infected ticks unless you move to a non-endemic area. You should provide protection from tick exposure. Frontline Plus is recommended, as well as any life style changes that you feel are appropriate. Ticks can be active year round. Exposure is most frequent in spring and fall. Keep in mind that if your dog was infected, you could be too if you have had tick exposure. You cannot become infected from your dog.
We will recommend a recheck of the Lyme C6, six months after treatment. The titer does not drop immediately. If the recheck titer is less than half of the original titer or less than 30, treatment is considered successful. If the titer does not drop enough, re-treatment may be necessary.