Tick Borne Illnesses in Canines

A dog can pick up ticks in your yard or a field.
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Ticks have become a major threat to canine health, with an estimated 30 percent of the U.S. dog population reported as having suffered from a tick-borne illness in the past five years. Ticks can be found in almost every area of the U.S. There are hundreds of types of ticks, but most canine tick-borne illnesses are carried by deer ticks, American dog ticks and brown dog ticks. Although the most common tick-related illness is Lyme disease, there are others that can be even more serious.

Lyme Disease

Lyme disease is carried by an infected deer tick -- a tiny insect the size of a pinhead. Lyme can lay dormant in a dog for weeks or even months, before manifesting with lameness on one or alternating legs, fever, lethargy, loss of appetite and overall stiffness. Any one of these symptoms can signal Lyme disease. Your veterinarian can diagnose the illness with a blood test performed and read in the office. Antibiotic treatment is fast and effective if the illness is caught early.


Ehrlichiosis is not as common as Lyme disease but reported cases are increasing. Carried by the larger brown dog tick found in every state, it is one of the most dangerous tick-borne illnesses. Like Lyme, symptoms may not surface for up to several months after the dog is bitten but progresses rapidly. Fever, swollen joints, loss of appetite, lethargy, nose bleeds, runny nose or eyes, weight loss or lethargy may be present. A blood test is needed to diagnose ehrlichiosis. Veterinary treatment involves several weeks of antibiotics.

Rocky Mountain Spotted Fever

This disease is transmitted by the American dog tick, the wood tick and the lone star tick. These ticks are found nationwide. Left untreated, Rocky Mountain spotted fever can cause liver or kidney damage, heart problems or pneumonia resulting in death in some cases. The tick must be attached to the dog for at least five hours to transmit bacteria. Symptoms may be neurological causing stumbling or seizures. Early symptoms can include fever, lethargy, loss of appetite, vomiting, diarrhea, joint pain or stiffness. Rocky Mountain spotted fever is diagnosed by a blood test, and a vet will prescribe several weeks of antibiotic treatment for the disease.

Canine Anaplasmosis

A dog can be infected with anaplasmosis by a deer tick or the Western black-legged tick. The brown dog tick carries another strain of the illness. Symptoms usually appear within a few weeks of being bitten and can include fever, joint pain, vomiting, diarrhea or nervous system disorders. A dog may suffer seizures in serious cases. Blood and urine tests will diagnose this illness, and treatment is several weeks of oral antibiotics.

Still More

The brown dog tick spreads babesiosis, bartonellosis and hepatozoonosis. Babesiosis causes joint weakness, vomiting and anemia and pale gums. A dog with bartonellosis will have occasional lameness and fever. Untreated, this illness can cause heart or liver damage. A dog who eats a brown dog tick may contract hepatozoonosis. He may have a fever, muscle pain, runny eyes or nose and diarrhea with blood. These illnesses all require veterinary diagnosis and treatment.