Rocky Mountain Spotted Fever in Dogs

Rocky Mountain spotted fever is a tick-borne disease that affects humans and dogs. Tick-borne means that the disease is carried and transmitted through a tick bite. In the U.S., the American dog tick and the Rocky Mountain tick are types that carry and transmit Rocky Mountain spotted fever. This disease is most commonly seen in the Southeastern United States, but can occur in any state, Canada, Mexico, and Central and South America.

Rocky Mountain spotted fever is diagnosed most frequently between April and October when tick populations are at their highest. Rocky Mountain spotted fever can be fatal if not treated.

Signs & Symptoms of Rocky Mountain Spotted Fever

Rocky Mountain spotted fever causes multiple symptoms in your dog, and most symptoms will start to appear three to ten days after a tick bite.

There are two stages of Rocky Mountain spotted fever.

Subclinical stage: A dog can be infected but will not be showing any outward signs or symptoms. However, if lab work is performed, abnormalities will appear. Dogs that are infected with Rocky Mountain spotted fever in the subclinical stage generally recover from the disease quickly.

Acute stage: A dog in the acute stage of Rocky Mountain spotted fever will be showing any combination of the common signs and symptoms associated with this disease. These include the following:

Loss of appetite
Fever
Pain in muscles and joints
Depression
Swollen lymph nodes
Edema (Fluid accumulation in the face and legs)
Coughing
Difficulty breathing
Vomiting
Blood in the stool
Dizziness
Ataxia (Inability to walk normally or loss of coordination)
Seizures
Nose bleeds
Retina bleeding
Blood in the urine
Pinpoint bruises that appear on lining of the eyelids and mouth
Irregular heart beat (arrhythmia)
Difficulty with blood clotting, which can lead to shock or death

Causes of Rocky Mountain Spotted Fever

Rocky Mountain spotted fever is caused when ticks that are carrying a bacteria known as Rickettsia reckettsii, bites your dog, thus transferring the bacteria into the bloodstream.

Diagnosis of Rocky Mountain Spotted Fever

Diagnosis begins with a complete history and a physical exam. Your veterinarian will most likely do the following:

History - Your veterinarian will likely inquire about recent tick exposure and bite history.
CBC/Chemistry Panel - These blood tests will evaluate various internal organ functions, including the heart, liver, kidneys, pancreas, metabolism, and electrolyte balance. The CBC is a measure of the amount and different kinds of red and white blood cells that are present in your dog’s body.
Skin biopsies – Samples from the affected areas are examined for antibody levels. If there is a heightened antibody count this indicates the disease is present. This test can take up to three weeks to complete, so treatment should be started while awaiting results.

Treatment for Rocky Mountain Spotted Fever

Your veterinarian will most likely start your dog on antibiotics as soon as he/she suspects that Rocky Mountain spotted fever may be present. Supportive care is sometimes necessary depending on what stage of the disease is present.

Prevention of Rocky Mountain Spotted Fever

Rocky Mountain spotted fever can be prevented by preventing tick exposure for your dog. Your veterinarian should already be recommending a monthly flea and tick preventive with their healthy pet program.