Rocky Mountain Spotted Fever In Dogs

Rocky Mountain spotted fever (RMSF) is a severe, infectious, zoonosis in dogs. Rickettsia rickettsii is a tick-borne, intracellular, obligate, gram-negative bacterium that is the causative agent of RMSF and Brazilian spotted fever in South and Central America. Rocky Mountain spotted fever is a misnomer as it is found all over North and South America.

Transmission of RSMF is through tick bites or activities that are associated with tick exposure. Ticks at any stage of development when infected can transmit the disease, from larval to adult. The tick species that are involved in spreading the disease varies with the geographical location. In the western US, the most common tick to transmit this disease is the wood tick and in the eastern US, it is the American dog tick. In Eastern US particularly in Arizona, the brown dog tick transmits the disease. Arizona is considered to be a high-risk area and almost 10% of ticks may carry the infection. RMSF is less common in Canada.

There are almost 23 rickettsial species that have been documented. There are 4 groups in the Rickettsia genus: spotted fever, typhus, Bartonella, and ehrlichiosis. While RMSF is categorized as a reportable infection in humans, the actual prevalence is considered to be underestimated.

Almost 5 - 20 hours of tick attachment is required for transmission and this makes timely removal of ticks a priority in preventing RMSF. Direct transmission between humans and dogs is not yet documented. Nevertheless, there are many reported cases of RMSF in dogs and humans living in the same geographic area or household that is caused by simultaneous contact with infected ticks. The average incubation period of RSMF bacterium in both humans and dogs is 7 days, with a range reported between 2 to 14 days.

• Joint pain and Fever
• Malaise
• Cough
• Abdominal pain
• Lethargy
• Loss of appetite
• Labored breathing
• Ataxia (lack of muscle and movement control)
• Chills
• Nosebleeds
• Vomiting and diarrhea
• Seizures
• Swelling of the face or extremities (edema)
• Swollen lymph nodes

Treatment protocol involves a course of antibiotics, pain relievers, anti-inflammatory drugs, and Supportive care such as IV fluids and iron supplements.

Tetracycline, doxycycline, fluoroquinolones (i.e., trovafloxacin, enrofloxacin), and chlor­amphenicol.

Doxycycline is the drug of choice (2–5 mg/pound of body weight/day, PO or IV). Most dogs respond within 12- 24 hours after the first shot of doxycycline.

Anti-inflammatory drugs and Analgesia may be needed for joint pain.

The common locations of ‘tick trail’ in dogs where the possibility of finding ticks is high.

1. Scalp
2. Ears
3. Groin Region
4. Under Legs
5. Under Collar( If Any)
6. Toes
7. Elbows
8. Under The Tail

• Several types of tick collars, oral medications, and topical treatments are available; check with your vet and decide what is best for your dog.
• The Autumn and spring seasons are when ticks are most active. Persistent tick prevention is recommended in the tick prevalent regions.
• Tick hotspots are shady and moist areas, shrubs, regions of tall grass, wood piles, and leaf litter. Fight your corner by weeding, mowing, or trimming the bushes near your house, and keeping the lawn manicured is always recommended.
• For significant tick infestation in your backyard, use garden treatments such as environmental-safe deterrents and tick sprays.
• Never allow your pet from wandering freely in suspected tick-infested regions such as places with high leaf litter and grassy forested pathways.
• If your dogs roam in tall grasses or bushes, perform a good, conventional "tick check” by checking ticks in their most favored places– in the belly, neck, ears, chest, toes, and back.
• All said and done, not all tick exposure can cause infection to most healthy dogs. But when it happens, early diagnosis and appropriate treatment are enough for the dogs.

There is no confirmed breed predisposition. However, outdoor dogs, hunting, and sports dogs are overrepresented. Purebred Dogs, German Shepherd

1. Causes:

1. RSMF is a vector-borne disease that is distributed worldwide.
2. RSMF bacteria are transmitted to the dog through tick and tick bites.
3. Incubation period is about 1 to 2 weeks with a median of 7 days.
4. Rocky Mountain spotted fever can resemble Acute ehrlichiosis symptoms

2. Types:

Sub-clinical Infection:

• Although the infection is still present, there will be no obvious symptoms.
• Dogs that have a healthy immune system can withstand the infection during this stage.

Acute infection:

• This affects the dog between 1-2 weeks after the infected tick bite.
• The most common symptoms are fever, myalgia, headache, abdominal pain, diarrhea, rashes, joint pain, and vomiting.

The chronic stage:

• The chronic stage follows the acute stage and this is the most serious stage of the infection.
• In the chronic stage, dogs may have low white-blood-cell counts and non-regenerative anemia.
• The affected dogs may experience hemorrhagic nasal bleeding, kidney disease, and Hemorrhagic diathesis.
• The infection may also spread into other organ tissues, especially those of the bone marrow, lymph nodes, lungs, liver, and spleen.

3. Mortality:

When the infection is diagnosed in the starting stage, it is usually cured with standard treatments. Disseminated and chronic RSMF can be really serious to the dogs.

4. Diagnosis:

• Complete blood count test (CBC)
• ELISA test
• Polymerase chain reaction (PCR) test

5. Prognosis:

RSMF prognosis is really good with proper treatment. Most dogs undergoing treatment will show improvement within one hour of starting the treatment. The chances of full recovery can be expected within a week. Severe cases of RSMF can be fatal for dogs, so head to your vet immediately.

• Joint pain and Fever
• Malaise
• Cough
• Abdominal pain

• Bioflavonoids and vitamin C: Broccoli, Brussel sprouts, spinach, kale, papaya, strawberries, and pineapple
• Yeast (such as nutritional yeast), Mutton Liver, green vegetables (cauliflower, cabbage, cantaloupe, Brussel sprouts, spinach, Kale, and silver beets)
• Vitamin B-12: Organ meat, Grass-Fed Meat, beef liver
• Iron: Beef liver, lean meats, raw egg yolk, canned sardines, salmon, pumpkin, and green vegetables
• Chicken soup bone broth (or use lamb/beef bones)

Not all RSMF infection manifests symptoms, some dogs may be asymptomatic. If the dog has symptoms, they usually appear within a week or two after being transmitted by an infected tick. RSMF symptoms should be attended immediately, if left untreated, it can be fatal for dogs, so head to your vet immediately.