Symptoms of RMSF in Dogs

RMSF, or Rocky Mountain spotted fever, is a tick-borne disease that affects dogs. Caused by the bacterium Rickettsia rickettsii, this disease is prevalent throughout North America, with specific ticks carrying the bacterium being more common in certain regions. While RMSF cannot be transmitted directly from dogs to humans, ticks can infect both species. Symptoms of RMSF in dogs include fever, lethargy, appetite loss, decreased red blood cells and platelets, and various other signs. Specialized testing is required for diagnosis, and early treatment with the antibiotic doxycycline is usually effective. To protect dogs from RMSF, it is crucial to prevent tick bites through regular checks and the use of tick repellents.

Symptoms of RMSF in Dogs


Fever is one of the most common symptoms of Rocky Mountain spotted fever (RMSF) in dogs. When infected with the bacterium Rickettsia rickettsii, dogs may experience an elevated body temperature. This fever is usually persistent and can range from mild to high. As a responsible pet owner, it is essential to monitor your dog’s body temperature closely. If you notice a fever lasting for more than a day or if it reaches a high temperature, it is crucial to seek veterinary attention promptly.


Lethargy is another symptom commonly observed in dogs with RMSF. Your usually energetic and active canine companion may appear tired and lack energy. You may notice that your dog is spending more time sleeping or resting and is less interested in participating in their usual activities. Lethargy can be a significant indication of an underlying health issue, including RMSF. If your dog seems unusually sluggish and shows a lack of interest in daily activities, it is essential to consult your veterinarian for further evaluation.

Appetite Loss

Loss of appetite is a concerning symptom that may accompany RMSF in dogs. Dogs generally have a healthy appetite and enjoy their meals. However, when infected with RMSF, they may experience a decreased desire to eat. This can lead to a reduced intake of vital nutrients and contribute to their overall weakness. If you notice that your dog is not showing interest in their food or has a significant decrease in appetite, it is important to address this symptom promptly by seeking veterinary advice.

Decreased Red Blood Cells

RMSF can affect various systems within a dog’s body, including the blood cells. One of the consequences of this disease is a decrease in red blood cells, leading to a condition known as anemia. Red blood cells are responsible for carrying oxygen to different parts of the body. When their numbers decrease, dogs may experience fatigue, weakness, and pale gums. If you observe any of these signs, it is crucial to consult with a veterinarian who can perform a blood test to assess your dog’s red blood cell count and determine the appropriate treatment.

Symptoms of RMSF in Dogs

Decreased Platelets

Platelets play a crucial role in blood clotting. When a dog contracts RMSF, the bacterium can affect platelet production and result in a decrease in their numbers. This condition is known as thrombocytopenia. Thrombocytopenia can lead to prolonged bleeding, bruising, and difficulty in clotting after minor injuries. It is essential to be vigilant and monitor your pet for any signs of excessive bleeding, such as frequent nosebleeds or blood in their urine or stool. If you notice these symptoms, seeking immediate veterinary attention is necessary.

Skin Rash

One of the characteristic symptoms of RMSF in dogs is the development of a skin rash. This rash is often observed on the dog’s abdomen and typically appears as red spots or raised bumps. The rash may progress and spread to other parts of the body as the disease progresses. It is important to note that the presence of a skin rash alone does not conclusively indicate RMSF, as several other conditions can cause similar skin manifestations. If you notice a rash on your dog’s skin, it is important to consult a veterinarian for proper evaluation and diagnosis.

Symptoms of RMSF in Dogs

Swollen Lymph Nodes

Lymph nodes are small, bean-shaped structures that play a vital role in the body’s immune response. When dogs contract RMSF, their lymph nodes may become swollen and tender to the touch. Swollen lymph nodes are usually an indication that the body is fighting off an infection. If you notice enlarged lymph nodes on your dog’s neck, shoulders, or behind their knees, it is crucial to have them examined by a veterinarian. Swollen lymph nodes can be a valuable clue for the diagnosis of RMSF and guide the appropriate treatment plan.

Joint and Muscle Pain

Dogs with RMSF often experience joint and muscle pain. This can manifest as lameness, reluctance to move, or discomfort when touched on certain areas of their body. Joint pain may be more noticeable when your dog attempts to walk or engage in physical activity. Additionally, muscle pain may cause your dog to exhibit signs of discomfort, such as whimpering or difficulty getting up. If you notice any signs of joint or muscle pain in your dog, it is essential to consult with a veterinarian to alleviate their discomfort and address any underlying causes.

Symptoms of RMSF in Dogs


Nosebleeds, also known as epistaxis, can occur as a result of thrombocytopenia caused by RMSF. With a decrease in platelet count, a dog’s ability to form blood clots is compromised. Even minor trauma to the blood vessels in the nose can lead to persistent bleeding. If you notice your dog experiencing frequent nosebleeds or if the bleeding does not subside within a reasonable amount of time, it is crucial to seek immediate veterinary attention. Nosebleeds can be potentially serious and may require medical intervention to stop the bleeding and manage the underlying condition.

Ocular Symptoms

RMSF can also affect a dog’s eyes, leading to various ocular symptoms. These symptoms may include redness, discharge, swelling, or increased sensitivity to light. Dogs may show signs of discomfort, such as pawing at their eyes or squinting. If you observe any abnormalities in your dog’s eyes, it is vital to consult with a veterinarian who can perform a thorough examination and provide appropriate treatment. Treating ocular symptoms promptly is crucial to preventing further damage to the eyes and ensuring your dog’s overall well-being.

In conclusion, RMSF in dogs can present with a wide range of symptoms, including fever, lethargy, appetite loss, decreased red blood cells and platelets, skin rash, swollen lymph nodes, joint and muscle pain, nosebleeds, and ocular symptoms. If you notice any of these symptoms in your dog, it is imperative to consult with a veterinarian for proper diagnosis and treatment. Early detection and intervention can significantly improve the outcome for dogs affected by RMSF. Remember to prioritize tick prevention measures to reduce the risk of your dog contracting this potentially serious tick-borne disease. Regular tick checks, tick repellents, and avoiding tick-infested areas can go a long way in protecting your beloved furry friend from RMSF.

Symptoms of RMSF in Dogs