In Ontario, Lyme disease is transmitted by the deer tick, Ixodes scapularis. It is estimated that 18% of the overall tick population in Ontario is infected with Lyme disease. The tick needs to be attached for greater than 24 hours for the disease to be transmitted, and it can take 2-5 months for a dog to start showing clinical signs. These clinical signs can include fever, anorexia, lameness and joint swelling. However, 95% of dogs that have become infected with Lyme disease never become clinical. Humans cannot get Lyme disease directly from an infected dog; they too need to be bitten by a tick infected with the disease.
Your vet can screen your dog for the presence of antibodies
to Lyme disease through a screening test called 4Dx. This test screens for Lyme
disease, as well as other tick-borne diseases (including Ehrlichia and
Anaplasma) and heartworm. Typically a veterinarian will recommend this
screening test after your dog has been bitten by a tick – but not immediately
after the tick is found; it can take 3-5 weeks for the antibodies to become
present in your dog’s system. It is also recommended as an annual screening
test, since we don’t always find every tick on our dogs – especially the really
hairy ones!
If your dog tests positive for Lyme disease on the 4Dx
screen test, it indicates that your dog has previously been exposed to the
disease and has developed antibodies against it. It doesn’t indicate an active
infection – in fact, some dogs that have been diagnosed with Lyme disease can
remain positive on their 4Dx screen for many years. Your vet will probably
recommend a further test to quantify the number of antibodies present to
determine the level of infection. If your dog is showing clinical signs of the
disease, treatment will be initiated.
So now we know what to do if your dog has been bitten by a
tick. But how about we prevent those ticks from ever latching on?
There are a variety of tick products available for dogs.
They range from topical products to oral products, with some collar options as
well. These products do not all protect against every type of tick, so be
careful when picking your tick product. Just because it says tick, doesn’t mean
it covers all the ticks common in your area (or the Lyme-disease-transmitting
Deer tick)!
A few of our favorite products for tick prevention include:
Bravecto - this oral product can be given once every 12 weeks to dogs and treats against fleas, Deer ticks, American Dog ticks and Brown Dog ticks. It cannot be given to dogs less than 6 months of age or less than 2 kg.
NexGard - this oral product is given monthly to dogs to protect against fleas, Deer ticks, American Dog ticks and Lone Star ticks. It is approved for puppies greater than 8 weeks of age.
Preventic Collars - this collared product for dogs protects against American Dog ticks and Brown Dog ticks. It can last for up to 90 days, but is not recommended for use in dogs with cats in the same household.
K9 Advantix II - this topical product is for dogs only. It repels fleas and all species of tick (American Dog tick, Brown Dog tick, Lone Star tick and Deer tick). It is to be reapplied monthly, but is not recommended for use on dogs with cats in the same household. It is safe for dogs greater than 8 weeks of age.
Revolution - this topical product is a great choice for cats (and also can be used in dogs). It is used to treat against fleas, Brown Dog ticks and American Dog ticks and should be reapplied monthly. It is safe for dogs and cats greater than 6 weeks of age.