Vet’s 2025 Guide to Rocky Mountain Spotted Fever in Dogs 🩺 Ticks, Treatment & Prevention

By Dr. Duncan Houston BVSc 

💡 What Is Rocky Mountain Spotted Fever?

Rocky Mountain spotted fever (RMSF) is a potentially severe and sometimes fatal tick-transmitted illness caused by the bacterium Rickettsia rickettsii. This pathogen infects the lining of blood vessels, leading to vasculitis. Dogs become infected when ticks, especially Dermacentor variabilis, Dermacentor andersoni, or Rhipicephalus sanguineus, feed and transmit the bacterium.

🐾 Who Is at Risk?

• Dogs in tick-endemic regions across North America—especially in wooded, grassy environments.
• Pets not on year-round tick prevention, frequently outdoors in leaf litter, dense undergrowth, or near wildlife.
• Any breed or age—though owners are more likely to notice illness in young, old, or immunocompromised dogs.

🔍 How Dogs Get Infected

Ticks must remain attached for 5–20 hoursfor transmission to occur. Commonly implicated tick species are:

• American dog tick (Dermacentor variabilis) – widespread East of the Rockies and parts of Pacific Coast.
• Rocky Mountain wood tick (D. andersoni) – Rocky Mountain regions.
• Brown dog tick (Rhipicephalus sanguineus) – found in warm parts of the U.S. and southwestern states.

🚩 Clinical Signs & Symptoms

Symptoms typically manifest within 2–14 days post-exposure.

• High fever (up to 40.5 °C/105 °F), lethargy, inappetence.
• Joint pain, generalized muscle aches, lameness.
• Cough, nasal or eye discharge, occasional nosebleeds.
• Gastrointestinal signs: vomiting, diarrhea, abdominal discomfort.
• Swollen lymph nodes, facial or limb edema.
• Neurological signs (in ~⅓ of cases): spinal pain, incoordination, seizures.
• Skin bleeding/necrosis from vasculitis in severe cases.

🧪 How Veterinarians Diagnose RMSF

• Thorough medical history—including tick exposure & no tick prevention.
• Physical exam: fever, lymphadenopathy, joint pain.
• Blood tests:
• CBC: thrombocytopenia, anemia, leukocytosis or leukopenia.
• Chemistry panel: elevated liver/kidney markers, low proteins.
• Serology (IFA titers) or PCR detection of Rickettsia DNA.
• In-house SNAP 4Dx test may support diagnosis, but cannot confirm RMSF.
• Additional imaging or labs to assess organ injury as indicated.

🩺 Treatment Protocol

Start treatment immediately upon suspicion, without waiting for confirmation.

Doxycycline 🧴

• Drug of choice: 5–10 mg/kg twice dailyfor at least 7–21 days, often 10–21 depending on severity.
• Most dogs improve significantly within 24–48 hours.
• If doxy is contraindicated, tetracycline or minocycline may be used; chloramphenicol is less effective.

Supportive Care

• IV fluids, anti-inflammatories, antiemetics, pain relief, blood transfusions if needed.
• Hospitalization for moderate-to-severe cases with organ or neurologic involvement.

📈 Prognosis & Long-Term Outcome

• Excellentwith early treatment—most recover fully and may gain lasting immunity.
• Serious complications occur in delayed cases: kidney failure, neurologic impairment, vasculitis, and bleeding disorders.
• Fatality rate in untreated dogs can reach up to 10%; swift treatment drastically reduces the risk.

🚫 Prevention Strategies

• Year-round tick prevention—topical, oral, or tick collars per veterinary guidance.
• Daily tick checks—especially after hikes. Prompt removal minimizes transmission risk.
• Environmental control—lawn mowing, barrier zones, acaricide for high-risk yards.
• Wear gloves when handling ticks, and secure bedding and kennels from tick infestation.

🏡 Ask A Vet Home Support

• 📅 Telemetry logs: temperature, appetite, mobility, cough/discharge.
• 🕒 Medication reminders: doxycycline dosing schedule and vet re-checks.
• 📸 Photo uploads: tick bites, rashes, limb/swelling to support remote vet assessment.
• 🔔 Alerts: signs like persistent fever, bleeding, neurological decline prompt urgent vet care.
• 📚 Educational modules: proper tick removal, prevention strategies, home recovery tips.

🔍 Key Takeaways

• RMSF is a tick-borne vasculitis disease—early suspicion and doxycycline save lives.
• Signs can mimic other conditions; fever + joint pain + tick history should prompt treatment.
• Diagnosis via CBC, serology/PCR—but treatment starts on clinical suspicion.
• Recovery is excellent if addressed early; delays risk severe systemic and neurologic damage.
• Prevent with tick control, daily checks, environmental management—ask A Vet enhances owner compliance.

🩺 Conclusion ❤️

In 2025, dogs still face threats from RMSF—but proactive prevention, daily tick vigilance, and rapid treatment with doxycycline can protect them. Integrating veterinary expertise with Ask A Vet’s app (reminders, monitoring, vet communication) empowers owners to manage risk, identify symptoms early, and ensure their pets recover fully. 🐾✨

Visit AskAVet.com and download the Ask A Vet app to log tick exposure, set medication reminders, upload updates, and stay connected with your vet—right from home. 📲