From Veterinarian professional Chloe Kehlbeck, learn all about about Lyme disease in dogs, including symptoms, testing options, treatment, and preventative care measures, and keep your furry friend protected.
Lyme disease in dogs is caused by a bacteria known as Borrelia burgdorferi that is transmitted by ticks. It is the same bacteria that causes Lyme disease in humans. Lyme disease is what is known as zoonotic - meaning it can be passed by different species to humans or animals. It is incredibly prevalent in the United States; in 2018 roughly 1 in 5 dogs routinely tested for blood parasites tested positive for Lyme disease antibodies.
Lyme Disease Symptoms in Dogs
Symptoms of Lyme disease in dogs include intermittent lameness - typically limping on different legs at different times - swollen lymph nodes, swollen joints, fever, fatigue, and decreased appetite. If left untreated, Lyme disease in dogs can lead to kidney failure. This makes prevention and early detection extremely important, allowing treatment to be started as soon as possible.
Standard Practice and the Idexx SNAP 4Dx test
The blood parasite test routinely used in Vet Hospitals in the US is a serum ELISA (Enzyme-Linked Immunosorbent Assay) test for vector-borne agents, produced by Idexx labs, known as a SNAP 4Dx. This tests for Heartworm disease (Dirofilaria immitis), and three tick-borne diseases - Lyme (Borrelia burgdorferi), Ehrlichia (Ehrlichia canis/chaffeensis) and Anaplasma (Anaplasma phagocytophilum/platys).
The American Heartworm Society recommends testing for Heartworm disease annually, because most hospitals routinely use the Snap 4Dx to do so, Lyme disease is also tested annually. The problem with a positive test is it does not necessarily mean your dog is symptomatic - just that they have been exposed to the bacteria, and have made antibodies against them. These antibodies do not develop immediately, and because of that these Snap 4Dx tests (which test for the antibodies) will not become positive until several weeks after your dog has been exposed and had time to develop antibodies.
If you find a tick on your dog and are concerned about tick-borne illness, most hospitals recommend delaying testing for at least 4-8 weeks after the initial tick bite to allow time for antibodies to develop and be detected. In some cases it can take anywhere from 2-5 months for symptoms to develop. By the time symptoms occur, the bacteria causing Lyme disease, may already be widespread in the body.
Our Job as Pet Owners - Be their Voice
Our job as responsible pet owners is to monitor our pets for symptoms of tick-borne diseases, and routinely test them for preventative care. Be their advocate and request further testing if you are concerned about a recent tick bite or increased risk of exposure. Dogs that spend a lot of time outside, especially in wooded areas, are considered at higher risk of exposure. Idexx laboratories (one of the foremost veterinary laboratories) offers a Tick/Vector PCR Panel (Tick Analysis) and further comprehensive PCR diagnostics (Polymerase Chain Reaction, a variety of test that amplifies and identifies DNA, instead of just antibodies from a virus or bacteria). The advantage of a PCR test over an antibody test is that antibodies take time for the body to develop, while a PCR test detects the DNA of a disease-causing agent much sooner.
In my experience in veterinary medicine, and through personal health & experience with Lyme disease - I have find it imperative to be an advocate for yourself, and your pet, should you suspect tick-borne illness. Dogs, like humans, can test positive for Lyme disease, then later have a negative antibody test. This doesn’t necessarily mean your dog does not have Lyme disease anymore, just that there are no detectable antibodies. Dogs, like humans, can exhibit Lyme-related symptoms intermittently and chronically. Since most dogs spend a great deal of time outside, this makes reinfection easier to occur; your dog can get bitten by a tick and be exposed to the Lyme bacteria again and again.
Lyme Disease Treatment for Dogs
Standard treatment for Lyme disease in dogs involves several weeks of antibiotics, and veterinarians may also recommend a urinalysis to evaluate kidney health - as late stages of Lyme can lead to kidney failure in dogs which can be fatal.
Lyme Disease Preventative Care for Dogs
There are two main types of prevention of tick-borne illness in dogs, the first being the use of flea and tick control, and the second being the Lyme vaccine. I cannot stress this enough - not all flea and tick control is created equal. Over the course of my career, I have seen dogs succumb to neurologic issues brought on by good intentioned owners who bathed their dog in over the counter flea and tick products. These products caused so much damage that these dogs had to be euthanized a few weeks later. What you should know about flea and tick preventatives is that all oral products are overseen by the FDA, and all topical products are overseen by the EPA. The EPA regulations on these products are not nearly as strict as the FDA’s regulations on oral products.
Oral products, however, do not repel fleas and ticks- instead they kill them after biting your pet when they consume the preventatives in your pet’s blood. This is why pet owners will often find dead ticks still attached or falling off their pet when on regular (oral) prevention. Some drug companies also have a Lyme Satisfaction Guarantee within their fine print. I highly recommend dog owners look for this guarantee on their products, and be sure you are purchasing your product from Veterinary hospitals directly. If you are not, you are foregoing this guarantee. The Lyme Satisfaction Guarantee from certain drug companies will cover up to $5,000 of diagnostics and treatments for Lyme disease if your dog was actively on their product, and up to $10,000 of diagnostics and treatment if your dog was using their flea and tick products AND also up to date on the Lyme vaccine. There are various stipulations in place, but in my own experience, this guarantee is not exercised as much as it could be by pet owners.
These products should be used regularly - often monthly - to be effective over the course of your dog's life. Veterinary professionals in the Mid-Atlantic region recommend flea and tick prevention 12 months out of the year. The second line of defense against Lyme disease in dogs is the Lyme vaccine. The Lyme vaccine is roughly 60% to 86% effective in dogs and targets the bacteria Borrelia burgdorferi not only in your dog, but within the infected tick when attached. The Lyme vaccine is administered in a series of two boosters - generally given two to four weeks apart, and then boosted annually. It is recommended to continue vaccinating against Lyme disease even if your dog has tested positive for Lyme exposure, as your dog can continue to be bitten by ticks and re-exposed throughout their lifespan.
One Health & Tick Prevention
The "One Health" Initiative is a movement of collaborations between physicians, including veterinarians, human physicians, dentists, nurses, and other medical disciplines. This collaboration focuses on shared issues such as emerging and endemic zoonotic diseases, biosecurity, food safety, and climate change. As Lyme disease is an endemic zoonotic disease, it falls under the One Health Initiative. While there is both a vaccine and many tick preventatives in veterinary medicine, the scope of prevention in human medicine has fallen behind, in my opinion. So many good tick preventatives are available for dogs, both oral and topical, and typically applications last at least a month.
Various bug sprays on the market for people typically last only a few hours. In addition to prevention, dogs who are seen for routine veterinary care are usually screened for exposure to Lyme disease annually. Merial, now part of Boehringer Ingelheim Pharmaceuticals, introduced Nexgard (afoxolaner) in 2013 as the first oral flea and tick prevention approved by the FDA. It changed the game in terms of prevention with its ease of use, and also effectiveness. While I don’t expect there to be oral tick preventatives in humans to the same extent as dogs; after a decade of oral preventatives in veterinary medicine, I had hoped human medicine would have come further in terms of tick-borne illness prevention at this point.
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Opinions expressed by contributors are their own.
Click below for more info on pets and Lyme disease:
Lyme Disease in Dogs: Dog Lyme Disease Life Expectancy
