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Rocky Mountain Spotted Fever in Dogs

Rocky Mountain spotted fever is spread by tick bites.

Rocky Mountain spotted fever is an illness caused by the bacteria Rickettsia rickettsii. The bite of infected ticks spreads it. Depending on the geographic area, several tick types can transmit the bacteria, including the American dog tick, the wood tick, and the brown dog tick.

An infected tick must be attached to the dog for at least 5 hours, and often up to 24, before the bacteria is transmitted. After that, it takes between 2 days and 2 weeks for the dog to start showing signs of illness.

Signs of Rocky Mountain Spotted Fever in Dogs

The signs of the condition can be quite varied. They tend to be vague and shared with many other conditions. Dogs with Rocky Mountain spotted fever may show one or a few of the following signs:

  • Decreased appetite
  • Shifting leg lameness from joint pain that moves from one joint to another
  • Fever
  • Cough
  • Vomiting
  • Diarrhea
  • Lethargy
  • Swollen face or legs
  • Nosebleeds
  • Tiny bruises (petechiae) in the whites of the eyes or on the gums
  • Wobbliness
  • Seizures

Diagnosis of Rocky Mountain Spotted Fever in Dogs

When you take your dog to the veterinarian because of the signs of illness listed above, the doctor will take a complete history from you and then do a thorough physical exam. The signs of Rocky Mountain spotted fever are similar to those caused by many conditions, including other tick-borne conditions such as ehrlichiosis, leptospirosis, and several autoimmune diseases (among many others). Some diagnostic tests, including blood work and x-rays, may help rule out other causes of the signs.

An IFA test (immunofluorescent assay) can confirm Rocky Mountain spotted fever, but it requires that two blood samples be sent to a special lab. The first blood sample is drawn when the signs are first noticed, and the second is sent several weeks later. If there are more antibodies to the bacteria found in the second sample, the condition is confirmed.

Of course, the dog must be treated in the amount of time necessary between the first and second blood samples, so often, the doctor begins treatment based on a presumption of the condition.

Treatment of Rocky Mountain Spotted Fever in Dogs

Rocky Mountain spotted fever is treated with a course of an antibiotic called doxycycline, which is given for up to 3 weeks. If the dog can't take that medication for some reason, there are some other antibiotics for the veterinarian to choose from.

Treatment is usually quite successful if antibiotics start early in the disease course, but once the condition progresses, it becomes less effective.

Preventing Rocky Mountain Spotted Fever in Dogs

Prevention of the condition focuses on good tick control. Ask your veterinarian for a recommendation on the best tick control plan for your area and then follow it carefully.

Additionally, make a habit of checking your dog daily for ticks after he's been out, especially in wooded or grassy areas. Learn how: "How to Find Ticks on Your Dog."

If you find a tick on your dog, remove it carefully. Wear gloves and use a tick removal tool if you have one. Learn more: "How to Remove Ticks."

Can Humans Get Rocky Mountain Spotted Fever?

Humans can become infected with Rocky Mountain spotted fever. They contract the infection the same way dogs do—through the bite of an infected tick. Humans can't get it directly from a dog, but if dogs in a particular area are getting the disease, that indicates it is in the tick population of the area. People should take precautions and check themselves for ticks often.

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How to Find Ticks on Your Dog

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How To Remove Ticks

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