Rocky Mountain Fever in Dogs: Causes, Symptoms, and Treatment

Adrienne is a certified dog trainer, behavior consultant, former veterinarian assistant, and author of "Brain Training for Dogs."

What Is Rocky Mountain Spotted Fever?

Rocky Mountain spotted fever is a debilitating disease caused by a species of bacteria known as Rickettsia rickettsii. The American dog tick (Dermatocentor variabilis) and the Rocky Mountain wood tick (Dermatocentor andersoni) are both the most common vectors of this disease.

How Is Rocky Mountain Spotted Fever Acquired?

The disease is transmitted when an infected tick feeds on the dog and delivers the rickettsial bacteria into the dog's blood stream through the saliva. However, this does not occur right away. In order to transmit the disease, the tick must be attached to the dog's skin for at least 5 to 20 hours, explains veterinarian Ann Marie Manning in Rocky Mountain Spotted Fever.

Since it is carried by tick bites, Rocky Mountain spotted fever is more likely to occur in the months when ticks are more active. This means dogs are most vulnerable in the spring and summer months from April to September.

Ticks love to hide in high grass and bushes where they eagerly wait for a warm body to pass by. These critters are capable of detecting the heat or carbon dioxide emitted by a living animal walking by, and they are ready to hitch a ride onto their next blood meal.

Curiously, despite its name, Rocky Mountain spotted fever is not limited to the Rocky Mountain states. Rather, it is pretty widespread and affects several areas of the United States. The East Coast, Midwest, and plains regions are the locations most likely to be affected. Howard T. Ricketts, an American pathologist, was the first to identify the infectious organism responsible for this disease, hence the name ''Rickettsia."

Symptoms of Rocky Mountain Spotted Fever

If your dog was bitten by a potentially infected tick, what happens now? Once the rickettsial bacteria have been delivered into the dog, it generally takes between 2 to 14 days for the symptoms of Rocky Mountain Spotted fever to manifest. Unlike humans who typically develop a skin rash, dogs usually exhibit a fever ranging from 102.6 to 104.9 degrees Fahrenheit about five days after the bite.

Because the rickettsial organisms tend to invade and kill blood cells, affected dogs may develop nose bleeds, bloody urine, bloody stools, presence of petechiae (pinpointed hemorrhages under the skin), and hemorrhages in the retina of the eye.

Other accompanying symptoms of Rocky Mountain spotted fever are lethargy, decreased appetite, enlarged lymph nodes, and swollen joints. Severely affected dogs may develop neurological signs, and renal failure and disseminated intravascular coagulation, a condition where platelets and clotting factors are destroyed.

Diagnosis of Rocky Mountain Fever

If you notice any unusual symptoms that suggest Rocky Mountain spotted fever regardless of any knowledge of tick exposure, it is imperative to have your dog evaluated by a veterinarian immediately. Because Rocky Mountain spotted fever may resemble a variety of other infectious and non-infectious diseases, several diagnostic tests may be required to confirm or rule out this disease. The test results and the clinical signs the dog manifests combined with its seasonal occurrence are often sufficient to confirm this condition.

Complete blood counts may reveal a mild degree of decreased platelets. Biochemistry profiles often find increased liver enzymes (serum alkaline phosphatase and alanine aminotransferase). Testing the dog's antibodies is one of the most useful means to detect infection with Rickettsia ricketsii. A dog with an active infection when tested serologically typically has a heightened antibody count.

Since Rocky Mountain Spotted Fever symptoms may mimic other tick-borne diseases such as Lyme disease and Ehrlichia, the veterinarians may submit blood for a "tick panel" that includes titers for each of the three diseases. A direct immunofluorescent testing of the tissue biopsies is one of the most effective venues for a rapid diagnosis.

Treatment and Prognosis of Rocky Mountain Fever

Tetracycline antibiotics are the medications of choice for treatment. When Rocky Mountain spotted fever is suspected, treatment should be initiated immediately. A delay or the wrong choice of antibiotics may result in a fatal outcome.

Dogs generally start responding to the antibiotic treatment within 24 to 48 hours. The antibiotics are prescribed for two to three weeks and should not be stopped earlier, even if the dog is doing better. Severe cases may require hospitalization.

The prognosis for Rocky Mountain Spotted Fever varies depending on its severity and the time lapse before treatment is started. Generally, when treatment begins immediately, the prognosis is good. However, lack of treatment or delays of hours or days may result in long-term consequences with devastating consequences on the nervous system and even death according to Pet MD.

The good news is that once infected, it appears that dogs that recover from Rocky Mountain spotted fever are immune to reinfection for years explains veterinarian Holly Nash in the article "Rocky Mountain Spotted Fever in Dogs."

Preventing Rocky Mountain Fever in Dogs

Good tick control is fundamental to prevent this potentially devastating disease. Dogs that spend time outdoors should be inspected thoroughly for ticks with owners paying special attention to areas where ticks like to hide such as under the armpits, between the toes, and below the ear flaps. There are several good tick control products on the market such as topical products to apply monthly and tick collars to prevent ticks on dogs. Rodent control also plays a big role since they are involved in the life cycle of ticks.

If a tick is detected and it is attached to the dog's skin, it is important to remove the tick in the correct way to prevent harmful secretions from spreading. Always wear gloves when removing ticks. Ticks should not be removed with the bare hands because while dogs do not spread Rocky Mountain spotted fever directly to humans or other dogs, humans may get it indirectly by contacting the tick's secretions when removing ticks.

Unfortunately, there are no vaccinations against Rocky Mountain spotted fever; Prevention is the key for keeping Rocky Mountain spotted fever in dogs at bay. Put your dog on a good tick preventive product, and always check for ticks after venturing in the great outdoors.

Questions & Answers

Question: How do I remove a tick from a dog?

Answer: If a tick is found embedded in the dog's skin; wear a pair of latex gloves, and, using tweezers, grasp the tick's head firmly as close as possible to the dog's skin. Pull the tick straight out from the skin using slow, firm traction, Never squeeze or twist, or the tick may release more pathogens. Preserve the tick in a jar of alcohol with a label and date just in case your dog gets a tick-borne disease or shows symptoms of one.

© 2011 Adrienne Farricelli

moonlake from America on December 14, 2011:

Good hub. I have never heard of Rocky Mountain Spotted Fever. People and pets do get Lyme’s Disease from ticks here.

Deborah Brooks Langford from Brownsville,TX on December 14, 2011:

this is a great HUB.. very useful.. I have a cat that goes out back but mostly stays in the house,.. I keep her with tick and flea medicine from the vet.. I thank you.. love the HUB.. I voted up and useful

Can A Tick Make A Dog Sick?

Common North American ticks such as American dog ticks, deer ticks, brown dog ticks and lone star ticks can pass on transmittable diseases- though it can take several days to several weeks before symptoms appear.

Initial signs of potential disease transmission include lethargy, vomiting, loss of appetite, weight loss and nasal or eye discharge.

In addition to the 5 relatively common diseases that are discussed below, other less common illnesses include Canine Bartonella and Canine Hepatozoonosis.

Lyme disease

Lyme Borreliosis is a severe, painful bacterial infection, but luckily it is rarely fatal.

It can take several months before symptoms appear, and they can include:

  • Depression
  • Loss of appetite
  • Fever
  • Lethargy
  • Swollen lymph nodes and swollen joints.

After a vet examination involving procedures such as blood testing, antibiotics such as doxycycline are often prescribed as they are necessary for long-term recovery. Once treated, your dog should begin feeling better within 5 days.

In severe cases where kidney failure occurs, hospitalization will be required and recovery will take longer.

Canine Babesiosis

Canine Babesiosis is a disease usually transmitted by deer ticks that has the ability to destroy red blood cells. It can be a difficult condition to treat due to the blood loss and potential shock that may occur.

The incubation period of Babesiosis is roughly 2 weeks, though diagnosis may not occur until several months or even years later.

Symptoms include depression, lethargy, pale gums, fever, swollen abdomen, skin discoloration and loss of appetite. Severe cases of canine babesiosis can cause anemia.

Rocky Mountain Spotted Fever

Rocky Mountain Spotted Fever is an illness that can be fatal if your dog is not treated promptly with antibiotics. It is usually transmitted by American dog ticks, rocky mountain wood ticks and brown dog ticks.

Symptoms can begin to show within 2 weeks and can include fever, lethargy, stomach pain, loss of appetite, skin lesions, swollen joints, swollen legs and vomiting.

In severe cases of Rocky Mountain Spotted Fever, kidney failure and seizures can develop.

Canine Ehrlichiosis

Canine Ehrlichiosis is a condition often transmitted by brown dog ticks or lone star ticks. It is caused by rickettsial organisms, and the disease is particularly severe in certain breeds such as the German Shepherd and Doberman.

Ehrlichiosis can usually be categorized into three different stages: acute, sub-clinical, and chronic.

Signs of canine ehrlichiosis in the acute phase include fever, lethargy, loss of appetite, shortness of breath, joint pain and stiffness, swollen lymph nodes and abnormal bruising and bleeding.

If the condition is allowed to become chronic, it will bring on severe symptoms such as anemia, bleeding, eye inflammation and fluid accumulation in the hind legs. Although rare, tick paralysis may occur.

Canine Anaplasmosis

Finally, canine anaplasmosis is another bacterial infection that can be caused by deer ticks. Symptoms generally develop around 7 days after being bit.

Symptoms of anaplasmosis include joint pain, lethargy, fever, loss of appetite. In severe cases, the condition can cause bleeding disorders, seizures and kidney disease.

Treatment also consists of the antibiotic doxycycline, and recovery is rapid once it is administered.

How Long Does It Take For Tick Bite Symptoms To Show Up In Dogs?

The appearance of tick bite symptoms can range from several hours to days- or even weeks!

Generic tick bite symptoms such as local swelling, redness and skin inflammation can appear within 2 days. These conditions can be quickly treated with the appropriate medication.

However, in the case of tick-borne diseases transmitted from tick bites, symptoms can develop anywhere from two weeks to two months following the bite. It will ultimately depend on the disease transmitted and your dog’s general health and wellbeing.

Tick-borne diseases begin transmitting after 12 hours of the initial bite, and are fully passed into the bloodstream in around 48 hours. Early removal of the tick reduces the chance of your dog becoming a victim to diseases.

Recovery of Rickettsial Infection in Dogs

As with any treatment at home, it's imperative to provide your loved one with a safe, quiet, and covered place to rest in as he recovers, as well as access to plenty of fresh water. Depending on your dog's symptoms, you may wish to restrict his physical activity, though many dogs begin to recover quickly after treatment is started. Monitor your dog for additional clinical signs, and if you observe any behavior that is out of the ordinary, let your veterinarian know immediately.

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Clinical Findings

Dogs are highly susceptible to clinical infection with R rickettsii in contrast, it is rarely diagnosed in cats. Early signs in dogs may include:

edema of the face or extremities

Petechial hemorrhages of the conjunctiva and oral mucosa may be seen in severe cases. Focal retinal hemorrhage may be seen during the early course of disease. Neurologic manifestations such as altered mental states, vestibular dysfunction, and paraspinal hyperesthesia may occur.

Thrombocytopenia is common. Leukopenia develops during the early stages of infection and, in untreated cases, is followed by progressive leukocytosis. Serum biochemical abnormalities may include hypoproteinemia, hypoalbuminemia, azotemia, hyponatremia, hypocalcemia, and increased liver enzyme activities. Case fatality rates of


Vascular endothelial damage is due to direct cytopathic effects of the rickettsiae, which reproduce within endothelial cells. Vascular endothelial damage and thrombocytopenia contribute to development of petechiae and ecchymoses. Necrosis of the extremities (acryl gangrene) or disseminated intravascular coagulation can develop in severely affected dogs.

Signs of Rocky Mountain Spotted Fever in Dogs

Signs of Rocky Mountain Spotted Fever in Dogs

  • Fever
  • A spotted "rash"
  • Bruising
  • Bleeding from the nose or mouth
  • Seizures
  • Coughing
  • Muscle pain
  • Joint pain
  • Abdominal pain
  • Swelling of the legs
  • Swelling of the face
  • Lethargy

Rocky Mountain Spotted Fever can be difficult to diagnose solely on symptoms. Signs of RMSF can vary greatly from skin rashes to facial swelling and joint pain. An increase in body temperature, bleeding from the nose or mouth, coughing, and even abdominal pain can all be symptoms of RMSF. Oftentimes dogs with this tick-borne illness also report muscle pain, lethargy, and swollen legs but not every dog has every symptom. Because of this variety of symptoms, it makes it hard to differentiate signs of RMSF from several other types of infections or ailments.

Rocky Mountain spotted fever is caused by infection with a rickettsia organism. Rickettsia organisms are classified somewhere between bacteria and viruses. The particular rickettsia organism that causes Rocky Mountain spotted fever is called Rickettsia rickettsii.

R. rickettsii spreads through the bite of the Rocky Mountain spotted fever tick, and through the bite of the American dog tick. It can't be passed from animal to animal, from animal to human, or from human to human. Transmission must occur through the bite of an infected tick. The tick must remain on the host for between 5 and 20 hours before the rickettsia organism can spread to the host. Most cases of Rocky Mountain spotted fever occur in the summer, when tick bites are most likely.

Watch the video: Symptoms of Lyme Disease in Dogs- And Why Its SO Dangerous - Professional Dog Training Tips (May 2021).