Ahhhh! The joys of nature. Enjoying the great outdoors with family, friends, our dogs ... and ticks! Yes, it is the tick time of year when your vet’s office is likely to receive calls each day from dog owners worried about lyme disease because they have found on a tick on their dog. Here is some information to help you understand all about ticks and lyme disease.

There are many different types of ticks. The scientific names for the ticks that transmit lyme disease are Ixodes scapularis, found in the northeast, southeast, and midwest, and Ixodes pacifica, found in western states such as California. Both Ixodes scapularis and Ixodes pacifica are commonly known as deer ticks.

Deer ticks, hard-bodied little parasites about 2 to 3 millimeters long, live for approximately two years during which they progress through three stages: larva (the immature stage of life after the tick has hatched from its egg), nymph (the juvenile stage), and the adult stage. Deer ticks are a conduit for lyme disease because a bacterial organism, called Borrelia burgdorferi, that lives on the deer ticks  transmits the disease.

Borrelia burgdorferi is a spiral–shaped bacteria known as a spirochete. Small rodents such as mice and rats are the main reservoirs for Borrelia burgdorferi. Deer ticks, when they are in the larva and nymph stages, often live on small rodents where they become carriers of Borrelia burgdorferi. Borrelia burgdorferi then gets passed on to your dog when a tick carrying the spirochete bites and feeds on your dog.

It takes approximately 48 hours of attachment and feeding on your dog for the tick to infect your dog with Borrelia burgdorferi. This means there is time between coming in contact with the tick and introduction of B. burgdorferi to either remove the tick mechanically or for a tick preventative, such as Frontline or Advantix, to kill the tick. It is therefore advantageous for you to inspect your dog daily for ticks and to ask your dog’s vet if a tick preventative medicine is appropriate for your dog. If you find a tick on your dog, you can remove it with sterilized tweezers. Use the tweezers to grasp the front of the tick as close to your dog's skin as possible. Once you have pulled off the tick, it is best to burn the tick to make sure it is destroyed. If you cannot burn the tick, you should place the tick in a sealed container (tupperware for example) and dispose of the container. Finish off by swabbing some disinfectant, such as hydrogen peroxide, on the area of your dog's skin on which the tick was located.

Your dog is considered to have lyme disease if he tests positive for Borrelia burgdorferi antibodies, and shows symptoms known to be associated with lyme disease. Antibodies are substance produced by the body’s immune system in response to a foreign invader, here Borrelia burgdorferi, and are designed to attack the foreign invader.

Symptoms of lyme disease include polyarthritis, kidney disease, and several non-specific symptoms. Polyarthritis is basically a wasting away of the joints in multiple locations throughout the body. However, polyarthritis will usually first manifest itself closest to the location where the deer tick has bitten your dog. Polyarthritis will cause your dog to have sudden, long-lasting or intermittent lameness that shifts from one part of the body to another. In addition, polyarthritis can create swelling and joint pain, anorexia, fever, lethargy, and swollen lymph nodes. The kidney disease associated with the infection is called protein-losing glomerulonephropathy and will cause kidney failure. Protein-losing glomerulonephropathy can occur in all dogs, but is mainly observed in Golden Retrievers and Labrador Retrievers. Symptoms of the kidney failure are lethargy, vomiting, ammonia-scented breath, a swollen/distended abdomen, and increased or severely reduced urination. Finally, common miscellaneous symptoms and signs associated with lyme disease include myocarditis (a heart infection), meningitis (a brain and spinal cord infection) and encephalitis (a brain infection).

There are six tests available to make a diagnosis of lyme disease. The most frequently used tests are each designed to detect the presence of antibodies to B. burgdorferi. However, there are also two tests sometimes used in which the organism itself is identified.

Two common antibody tests are the ELISA (enzyme-linked immunosorbent assay) test and the IFA (indirect fluorescent antibody) test. Both of these tests are only accurate beginning 4 to 6 weeks after your dog's has been exposed to B. burgdorferi. After this period, a positive test result will mean that your dog has been exposed to the organism. However, if your dog has had the lyme vaccine test, he will test positive regardless of whether he has actually been exposed to the organism. Another problem with these tests is that can have cross-reactivity with other types of organisms which means that these tests can produce a positive result if your dog has been exposed to other organisms besides the lyme disease-causing B. burgdorferi. In areas with high deer tick populations, vets often see many dogs who test positive for B. burgdorferi with ELISA or IFA tests, but never develop clinical signs or symptoms of lyme disease. These dogs are considered subclinical because of the lack of clinical signs. It is still controversial if sub-clinical dogs should be treated.

In addition to the ELISA and IFA antibody tests, there is the C6 Antibody Test. The C6 is specific for antibodies to natural infection, and therefore, unlike ELISA and IFA, will not give false positives if your dog has been vaccinated against lyme disease. In addition to indicating whether or not your dog has been exposed to the bacteria causing lyme disease, the C6 can tell the vet the amount of antibodies in your dog’s body. A high antibody load may persuade the veterinarian to begin treatment even if your dog has no clinical signs or symptoms of lyme disease. However, there is still controversy as to the accuracy of the quantitative test.

The fourth available antibody test is called the Western Blot Assay. The Western Blot Assay provides your vet with information similar to that gained from the C6 test. However, the Western Blot Assay is much more cumbersome and expensive to perform. Thus, this test is not used as much as the other antibody tests.

Finally, there are two test methods, PCR (polymerase chain reaction) and skin cultures, which are used to identify B. Burgdorferi itself rather than merely identify the presence of antibodies to the organism. The PCR test, which detects the presence of B. Burgdorferi’s DNA within your dog’s body, can produce false negatives because of the variability of the organism’s location in your dog’s body. The skin culture test, where your vet takes a tissue sample near the tick bite location, presents the problem of locating the exact tick bite spot. In addition, it is very difficult to culture B. burgdorferi due to organism’s fastidious growth requirements. Finally, both PCR and cultures are highly specialized tests which may not be available at your veterinarian’s office.

Lyme disease is a tough disease to treat as B. burgdorferi undergoes many changes in your dog’s body. The main treatment is generally to put your dog on antibiotics for at least one month. The most common antibiotics prescribed are doxcycline and amoxicillin, and you should see an improvement in your dog’s symptoms after about 4 days of treatment. If your dog is suffering from organ-specific symptoms, such as protein-losing glomerulonephropathy, treatment will begin to support the impacted organ’s functions.

Preventing lyme disease starts with preventing ticks from getting onto your dog. If you and your dog live in an area where exposure to deer ticks is a possibility, you should put your dog on an appropriate tick preventative. In addition, you should inspect your dog daily for ticks. Immediately remove any ticks you may find on your dog. Finally, there is a lyme disease vaccine available for dogs. However, the vaccine is not 100% effective and may not be appropriate for every dog. You should discuss with your vet whether or not it make sense to vaccinate your dog against lyme disease.