Rocky Mountain Spotted Fever (RMSF) is a tick borne illness found in dogs in many US states, that causes a host of symptoms ranging from mild to potentially life-threatening. Today our Charlotte vets explain what causes Rocky Mountain Spotted Fever in dogs, as well as the most common symptoms and treatments.
About Rocky Mountain Spotted Fever
Rocky Mountain spotted fever (RMSF) is an acute, tick-borne disease seen in dogs throughout the USA, with higher numbers of reported cases in southern Atlantic states, western central states, and areas of the mid-Atlantic and southern New England coastal states.
Caused by an intracellular parasite called rickettsia rickettsii, this disease is transmitted to dogs through the bite of an infected Rocky Mountain wood tick, American dog tick, or brown dog tick.
For transmission to occur an unfed tick needs to be attached to your dog for more than 10 hours, however if a tick has already fed it is capable of transmitting the disease to your dog in as little as 10 minutes after attachment.
Signs & Symptoms of Rocky Mountain Spotted Fever in Dogs
Signs and symptoms of Rocky Mountain Spotted Fever begin to appear between 2 - 14 days after the bite occurred and can be extremely varied. Since many of the symptoms of this disease are common to other conditions also, knowing if and when your dog may have been exposed to ticks can help your vet diagnose your dog's condition.
Common signs and symptoms of Rocky Mountain Spotted Fever include:
- Poor appetite
- Non-specific muscle pain
- Joint pain
- Abdominal pain
- Vomiting
- Diarrhea
- Swelling of the face or legs
- Fever
- Lethargy
- Inappetence
- Pain
- Eye/nose discharge
- Nosebleed
- Cough
- Enlarged lymph nodes
- Lameness
About 20% of dogs may also experience tiny hemorrhages in the skin, and up to 1/3 of dogs infected dogs will experience symptoms related to the central nervous system such as lack of voluntary coordination of muscle movements, weakness, balance problems, seizures, or spinal pain. Any organ in the dog's body could be affected by Rocky Mountain spotted fever and the symptoms can range from mild to severe or even life-threatening.
Diagnosis
When diagnosing Rocky Mountain Spotted Fever in dogs, your vet will look for any of the signs of the symptoms listed above, and possibly perform a series of diagnostic tests including: basic blood tests, urinalysis and x-rays.
Test results that point to Rocky Mountain Spotted Fever include low numbers of platelets, red blood cells (anemia), and abnormal white blood cell counts on complete blood count (CBC) results. Other diagnostic tests could detect low protein levels, abnormal calcium levels, electrolyte abnormalities, and abnormal liver or kidney values which point towards a diagnosis of this condition.
Treatment
Antibiotics are the main form of treatment for dogs diagnosed with Rocky Mountain Spotted Fever. Most dogs respond to the antibiotic treatment within 24 to 48 hours, although dogs with severe cases of the disease may not respond at all to treatment. The most common antibiotics used are tetracycline, doxycycline, and minocycline. In some cases, your vet may also recommend a blood transfusion to treat anemia or other supportive therapies.
Prognosis
In dogs that are diagnosed and treated for Rocky Mountain Spotted Fever early, the prognosis is good and there tends to be few complications associated with the condition. In many cases lifelong immunity will occur after the infection has been cleared.
Dogs with more advanced cases of Rocky Mountain Spotted Fever, which are treated later are at higher risk for complications of the disease such as kidney disease, neurological disease, vasculitis, and coagulopathies. In these cases the prognosis is guarded since complications can be severe.
Prevention
To help prevent your dog from Rocky Mountain Spotted Fever, limit your dog's exposure to ticks and tick-infested areas, particularly during peak tick months from March through October.
Whenever your dog has been out in areas known to have ticks, inspect your dog closely. The sooner you can remove a tick after it attaches to your dog, the better your chance that the organism will not have had time to infect your pet. Always wear gloves when removing ticks from your dog to avoid being infected through cuts and scratches on your hand. Tick remover tools are inexpensive and readily available at pet stores and vet's offices. These small tools can make removing ticks faster and safer for you and your dog.
Use of year round tick prevention medications is also recommended to help protect your dog against a host of tick borne diseases including Rocky Mountain Spotted Fever, Canine Ehrlichiosis, Lyme disease, tularemia, and Canine Babesiosis. Contact your vet to learn more about parasite prevention.