In the paragraphs that follow, we will explain the tick-borne diseases found in our region:  Lyme Disease and Ehrlichiosis.  We will briefly cover the symptoms, diagnosis, and treatment of these diseases.  In addition, we have a section on preventing tick infestation at the end.
This page is meant only to serve as an introduction to these diseases.  If you have specific questions or concerns about your pet, please contact us at one of our hospitals for further information.

Ticks are commonly found in Illinois.  There are two main types of ticks common to this region:  Deer Ticks and Brown Dog Ticks (sometimes known as Wood Ticks).  They're most abundant in the spring, summer, and fall.  They live in low bushes and tall grass, where, as your pet passes through, they can come in contact with their (or your) skin.  (Ticks don't jump, fly or dive off trees, as is commonly believed.)

                                                                                                 
                                Deer Tick
                                 (Ixodes)                                                    Dog Tick
                                                                                              (Dermacentor)
 
 

Lyme disease is one of the most common tick-transmitted diseases in the world, caused by the spirochete Borrelia burgdorferi.  While Lyme disease has been reported in cats, it is primarily a disease of dogs (and people).  Lyme disease in people is also caused by ticks - infected dogs cannot spread the disease directly to people.

The spirochete, Borrelia burgdorferi., is transmitted by the deer (Ixodes) tick.  Infection takes place after the tick is partially engorged, 24-48 hours after the initial attachment.  Infection is generally transmitted by the nymphal stage of the tick in the spring and the adult female tick in the fall.  Ixodes ticks have a 2 year life cycle.  Larvae hatch in spring and become infected by feeding on white-footed mice, which are persistently infected.  The larvae molt into nymphs in the spring of the following year and stay infected or become infected by feeding on mice.  Nymphs molt into adults in late fall of the second year.  Adult female ticks engorge after mating on deer or other mammals, fall off, and hid under leaves until the following spring when they lay eggs.   Adult male ticks tend to stay on the deer.  Once a dog has been infected, the incubation period prior to clinical disease is thought to be 2-5 months.

The dominant clinical feature in dogs is recurrent acute arthritis with lameness, sometimes with fever, anorexia, and depression.  During the acute lameness, one or more joints may be swollen and warm and may be painful when manipulated.  Dogs may walk stiffly with an arched back and may be sensitive to touch.  Lameness generally lasts for only 3-4 days.   Interestingly, only about 5% of dogs who have been exposed to Borrelia actually develop clinical disease.

Diagnosis is based on clinical signs, response to therapy, and blood tests for the presence of antibodies to Borrelia.   However, classic antibody tests (ELISA) cannot distinguish between antibodies resulting from natural infection and those resulting from vaccination.  There is a more specific test, called a western blot protein electrophoresis which can more accurately distinguish the different types of antibodies.  However, positive results only indicate a previous exposure to Borrelia and must be combined with clinical signs and interpretation to be diagnostic of Lyme disease.

Treatment consists primarily of antibiotic therapy.  The most commonly prescribed antibiotics for Lyme disease are doxycycline and amoxicillin.  The duration of treatment is somewhat controversial, but generally a treatment of 2-4 weeks is recommended.  Restricted activity is often recommended until the lameness resolves.  Improvement is generally quite rapid, occurring in the first few days of treatment.

Prevention against Lyme disease is best obtained by avoiding tick infestation and by vaccinating.  Lyme vaccination has been found to be quite effective in dogs that have not been previously exposed to Lyme disease, so beginning the vaccinations in young dogs is advisable.  Dogs which are seropositive (have previously been exposed) will obtain some degree of protection against future Lyme infection, but vaccine failure is more likely in these dogs.
Because of the risk of other disease (ehrlichia) and the potential to bring ticks into contact with humans, it is also strongly advisable to prevent tick infestation, even in dogs who are vaccinated against Lyme disease.  See the section below - preventing tick infestation.

Ehrlichiosis is a tick-borne rickettsial disease which has been recognized more frequently in our region in recent years.  Ehrlichiosis occurs in dogs and cats and can also occur in people    Like Lyme Disease, Ehrlichia in people is caused by a tick - you cannot get it from your pet.

Ticks transmit Ehrlichia in their saliva.  Both deer ticks and dog ticks have been implicated as carriers of Ehrlichia.   Clinical disease can occur after a 1-3 week incubation period.  Ehrlichiosis can occur at any time of the year.

The signs of Ehrlichiosis are more subtle than those of Lyme disease.  For this reason, many animals are infected months prior to seeking medical attention.  Typical signs include lethargy, depression, anorexia, weight loss, fever, bleeding tendencies, labored breathing and often enlarged lymph nodes.  Diagnosis is made through clinical assessment, bloodwork (numerous changes found in a complete blood count) and by obtaining Ehrlichia blood titers.

Prognosis is excellent in acute cases.  Chronic cases may take over a month of treatment to clear and those in which the bone marrow is not responding correctly have a poor prognosis.  Therefore, early recognition and treatment affords the best opportunity for a successful outcome.  The primary treatment is with the antibiotic doxycycline.  In addition, glucocorticoids may be indicated in acute cases with serious blood disorders.  Supportive care must also be given, including fluid support and blood transfusion when necessary.   Frequent monitoring of blood during therapy is crucial.

There is no vaccine against Ehrlichia.  Therefore, prevention is obtained exclusively through preventing tick infestation.  (see below)

There are numerous flea and tick products available in the marketplace today.  How do you choose the best product for your pet?  We have seen many new products in the past few years and with national advertising campaigns, most of the products are gaining name-recognition.  However, they are not all as effective as the advertising would lead you to believe.

It is important to remember that not all flea products protect against ticks.  Many of the prominently advertised preventives protect against fleas only.  Examples include Program®, Advantage®, and Sentinel®.  Make sure that the product you choose is effective against fleas and ticks.  Cat owners should be particularly careful, because most tick preventives used in dogs are not safe for cats.

The tick preventive we believe works best is Frontline® Top Spot which protects against fleas and ticks and available for dogs and cats.  It combines a high safety margin with an effective flea and tick kill.  Frontline® is a "spot-on" product which covers the entire body by spreading in the natural oils of the skin.  It effectively repels water and will remain effective even if your pet likes to spend time in the water.

Frontline® is fully guaranteed - if you are not completely satisfied for any reason, we will replace it or refund your purchase price.

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