Vetcetera | When Your Dog has Tested Positive for Lyme

When Your Dog has Tested Positive for Lyme Go Back

Is this an emergency? How serious is it?
A positive test for Lyme is usually not an emergency, especially if your dog seems generally healthy. There are some rare exceptions to this noted in the next section. About 10-15% of infected dogs show signs. Considering the many infected dogs in our area, this is actually a large number. Most dogs that are treated for Lyme Disease do very well, though they rarely "clear" the organisms from their system but usually remain subclinical.

What causes Lyme Disease and how is it transmitted?
Lyme Disease is a bacterial infection transmitted by ticks. The name of the bacteria is Borrelia burgdorferi. Lyme Disease first appeared in the late 1800s. The type of tick in the northeastern U.S. that transmits Lyme Disease is the deer tick, Ixodes scapularis. There ARE other types of ticks that can transmit Lyme, and this is especially a consideration for dogs that travel. Deer ticks are generally smaller than a sesame seed. A tick must remain on a dog (or person) a minimum of 18-24 hours before it can transmit the bacteria that cause Lyme Disease.

What are the consequences of Lyme Disease in dogs?
The most common signs of Lyme Disease are lameness (often shifting legs), lethargy, swollen lymph nodes and fever, although these are not specific to Lyme. More serious and less common syndromes are possible: kidney disease, heart disease and neurologic disease. Signs in dogs tend to occur 2-5 months after infection with Lyme bacteria, not immediately. The test that we use in our hospital (Heartworm/Lyme/Ehrlichia/Anaplasma - which checks for heartworm disease and 3 tick borne disease) takes 3-5 weeks post-exposure to become positive for Lyme. The vast majority of dogs that test positive for Lyme are lifelong carriers. The B. burgdorferi bacteria that causes the disease is a master of disguise! It can change the proteins on its surface, as well as its shape. For this reason, the immune system doesn’t recognize it well, and exposure does NOT confer immunity. It is possible for a dog to get infected with the Lyme bacteria over and over, unlike many diseases where after one infection, protective immunity is acquired.

Can I get Lyme Disease from my dog?
No. Lyme Disease is transmitted to dogs and people via ticks. However, be aware that if your dog has tested positive for Lyme, then it is in an environment (unless your dog has moved, had a lifestyle change, etc.) where there are ticks that can potentially transmit Lyme to you and your family.

Is further testing necessary?
Our in-house Lyme test is either positive or negative; it has a color change only. The test detects antibodies to the Lyme bacteria, but isn’t able to give us an actual number of antibodies in the bloodstream. The test is not fooled by vaccination for Lyme Disease; it can differentiate between natural and vaccine-induced antibodies. Testing for antibodies is not the same thing as testing for the bacteria itself, although recall that once a dog is infected, they are generally lifelong carriers, so if antibodies are present, so are bacteria. Antibodies can remain in the bloodstream literally for years. A high amount of antibodies generally means a large number of bacteria in the body.

We recommend a blood test that we send to a special laboratory for those dogs that are positive on our in-house test. This test is called a Quantitative C6 and takes about 1 week for results. It actually quantifies the antibody level, or gives a specific number of antibodies. Based on this, we can determine if treatment is recommended. The Quantitative C6 also gives us a baseline for future monitoring, allowing us to determine if treatment was effective, or if it needs to be performed or redone in the future.

The key point about this C6 quantitative test is that the level correlates with the level of circulating antigen-antibody complexes, which are the components thought to cause the dog significant pathology, such as life-threatening kidney disease. The C6 test is about $115.

We also recommend a urine test to check for protein in the urine. This includes a full urinalysis and quantitative protein check if necessary. This is recommended as a screen for Lyme nephritis (kidney disease), especially in high risk breeds such as Labs, Golden Retrievers and Shelties. This test is about $55. This test also provides other valuable information on general health.

Depending on the specific case and above results, we may recommend further blood testing to evaluate the general health of your dog. We want to make sure in every way possible that your dog doesn’t either already have, or begin to develop some of the more serious consequences of Lyme Disease mentioned above, such as kidney disease, which can ultimately be fatal.

Should treatment be started?
If determined necessary based on testing, history and physical examination, treatment consists of a long course of antibiotics, generally 4-6 weeks. There are several types of antibiotics available. Our treatment of choice is doxycycline, which is generally well tolerated, but may rarely cause some stomach upset, which would lead to trying an alternative.

The Lyme organism is simply too good at hiding to be eradicated by even a long course of treatment. The goal of treatment is to knock down the levels of bacteria to a point where the organism does not cause signs due to active infection.

Is vaccination recommended?
Yes, in most cases, though this is highly controversial. We believe all vaccination protocols need to be tailored to the individual. When a dog has tested positive for Lyme, it shows that it is an at-risk dog. As discussed above, dogs do not develop a good immunity on their own through natural infection. They can get infected over and over again. It is for this reason that we recommend Lyme vaccination in the vast majority of dogs that are not currently vaccinated, and test positive for Lyme. It is to help prevent future infection. Vaccination does not treat a current infection.

Note that there are multiple brands of Lyme vaccines on the market. At Vetcetera we use the vaccine that we consider to be superior in terms of safety, which is made using a unique technology.

How else can I protect my pet from Lyme Disease?
Tick control. If ticks can’t get on your dog and stay there for at least 24 hours, they cannot transmit Lyme Disease. Because deer ticks are so small, it would be practically impossible for you to always find and remove them, although tick removal is one component of prevention. Further protection from Lyme Disease is necessary, and is outlined below.

We recommend a four-part protection plan:

Frontline Plus monthly, year round. This is a recent recommendation change based on how many cases of Lyme we are seeing in our practice, and the fact that we are finding ticks all year long on some animals. In dogs with lots of tick exposure, Frontline Spray may be recommended instead of the spot-on, as the spray is actually more effective. Frontline by itself is not protective against Lyme disease. There are other options such as a Preventic collar, but each product has its own pros and cons list for usage. A combination of Frontline and this Preventic collar is ideal. The Preventic collar cannot be used in dogs that swim frequently, and would pose a serious problem if your dog or another dog would get the collar off and ingest any part of it.

Vaccination against Lyme. This is optimally done BEFORE the dog is Lyme positive, for obvious reasons.

Try to limit or eliminate access to areas with ticks, which tend to be areas with trees, bushes and tall grass.

Check your dog frequently for ticks, especially after going into high-risk areas.

Is monitoring recommended?
Generally we do periodic blood and urine checks.
This is especially important for three reasons:

To follow up on dogs that have been treated and evaluate treatment effectiveness.

A C6 level is recommended at 6 months after a treatment course and then annually to monitor organism levels, bearing in mind that dogs are lifelong carriers

The urine testing is recommended annually, with the exception of the high risk breeds for Lyme nephritis noted above. These dogs we recommend biannually testing of the urine for protein.

To monitor general health and get advance warning if any of the more serious forms of Lyme Disease begin to occur.

What about cats? Can they get Lyme Disease?
Cats have been experimentally infected, and rarely if ever show signs of the disease. For practical purposes, Lyme Disease is not a concern for cats. HOWEVER, there are other tick-borne diseases that ARE a concern for cats. Therefore three of the four steps in tick protection apply to cats as well, and are important (we do not vaccinate cats for Lyme Disease).

The last word...
Ultimately please understand that even among the community of Lyme researchers around the world, significant controversy exists on recommendations for treatment of Lyme positive dogs without symptoms, vaccination, etc. We have done our best to factor in all information and research currently available and recommend the best for our patients. Please call with any questions or concerns, or to set up an appointment for appropriate testing.