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Rocky Mountain Spotted Fever in dogs, causes, symptoms, treatment strategies and finally prevention
A lot of dog guardians must’ve heard about the Rocky Mountain Spotted Fever. However, if you have not heard of this disease before, you have come to the right place. In this blog post, I will be discussing everything about this tick related disease and preventive measures.
Rocky Mountain Spotted Fever is mainly caused by transmission of blood and saliva from ticks to your dog. It can be a pretty fatal disease if not treated immediately. Follow the blog post all the way to the end to understand the causes, symptoms, treatments as well as preventive measures of this dreaded disease.
What is Rocky Mountain Spotted Fever?
Rocky Mountain Spotted Fever or RMSF is a disease which is caused by the parasitic bacteria known as Rickettsia rickettsii. This bacterium is generally transmitted via the blood and saliva of ticks. Only the presence of this bacteria on the dog does not make the animal sick. However, if the ticks who generally carry these bacteria bite your dog, the bacteria gets transmitted from the saliva and blood of the tick into your dog’s bloodstream. This can lead to a life-threatening condition if the dog is not provided proper medical care as soon as possible.
Prevalence of RMSF
This disease has most often been observed in the Central, South as well as North regions of America and is currently one of the most prevalent tickborne disease in the above-mentioned regions. If you think that your dog is showing any signs and symptoms of the Rocky Mountain Spotted Fever, do not cause any delay in consulting your veterinarian. The sooner your dog gets the treatment, the better the chance of a full recovery.
Other articles in the Dog Tick series:
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What are the causes behind Rocky Mountain Spotted Fever in dogs?
The mode of transmission of Rocky Mountain Spotted Fever generally involves ticks. The tick will first bite an animal who is already infected with the bacteria, Rickettsia rickettsii. Now the tick has the microorganism in its circulation. Next, the tick will go and bite another uninfected animal. During the process of sucking blood, the tick will transmit the microorganism Rickettsia into this uninfected animal’s blood, thus infecting him or her. Ticks have also been observed to pass Rickettsia into their mates or their eggs.
In the US, the main carriers are the American dog tick in the East and the Rocky Mountain wood tick in the West. In parts of Arizona and the Southwest, the brown dog tick spreads it (VCA, Merck). Despite the name, the most cases are reported in the southeastern and south-central states (Merck).
There are several species of ticks which have been observed to transmit this disease. The bacteria may also get transmitted during the process of blood transfusion if the blood being transfused has been taken from an infected dog. This is however a less commonly observed scenario.
Certain dogs are at high risk for developing symptoms of RMSF. Purebred dogs may get sicker than mixed breeds. Dogs living in regions where the prevalence of ticks is high or those who spend a lot of their time outdoors are more likely to get infected by this disease.
Ticks are most active in the warmer months, but in many parts of the US they can be found all year, and brown dog ticks can live indoors in every season. That’s why the Companion Animal Parasite Council recommends keeping every dog on a tick preventive all year round (CAPC).
How much time does it take for the symptoms to develop?
An infected tick has to feed on your dog to pass on the bacteria. Researchers once thought this took several hours, but studies show it can happen faster (VCA), so remove ticks as soon as you find them. Once the parasite has gained access to your dog’s bloodstream, it will enter into the blood vessels and reproduce there. This will lead to the constriction and inflammation of the affected blood vessels. The incubation period (the duration when the animal is infected but not showing symptoms) of this disease is generally two days however it can take as long as two weeks for your dog to start showing symptoms.
Symptoms of Rocky Mountain Spotted Fever in dogs
Some dogs even after infection with RMSF may not show symptoms i.e. they may be asymptomatic. However, in other cases, the dog may develop severe and deadly symptoms of RMSF. The trouble here is that the symptoms of RMSF may be nonspecific and might mimic the symptoms of other canine diseases. Hence, if you are worried that your dog might be suffering from RMSF, do not delay in consulting your veterinarian.
In case you observe the presence of tick on your dog’s fur or if you see a tick bite on your dog, followed by the following symptoms, consult your veterinarian immediately:
- anorexia
- loss of appetite
- weakness
- Fever
- lethargy
- discolored spots on the skin which look bruised or purple in color
- presence of blood in urine
- abdominal pain
- joint pain
- coordination loss
- swelling of the face or limbs
- difficulty in breathing
- exercise intolerance
- diarrhea
- vomiting
- redness observed in the eyes
- bleeding from the nose or in stools
- prolonged bleeding [no coagulation of blood]
- swelling the lymph nodes
- seizures
- neurological signs and symptoms like wobbly walk
- haemorrhages in the eyes and gums
- arrhythmia
- changes in normal behavior
- necrosis of the extremities due to formation of gangrenes
- Shock
- Coma
Identification of Rocky Mountain Spotted Fever in dogs:
When you take your dog to your vet, he or she will ask you a few questions like when did you first observe the tick on your dog, what signs and symptoms has your dog been displaying, how long from observing the tick bite did the symptoms start etc. Your vet will conduct a thorough examination of your pup’s fur, and identify if there are any ticks remaining on your dog. They may also have to shave certain regions if your dog has a thick fur coat. Once the tick has been removed, your vet will most likely send the tick for a species examination to identify the exact disease that your dog is suffering from.
Your vet may also conduct a few basic blood tests, x-rays as well as urinary analysis. The abnormal findings would be a low number of platelets, anemia as well as abnormally high levels of white blood cell count. If your dog is still in the early stages of the disease, the white blood cell count might be low. However, if your dog is in the late stages of the disease, the white blood cell count would be elevated.
The biochemical tests will show reduced protein levels, abnormality in the calcium levels, abnormalities in the electrolyte, liver and kidney values.
What is the confirmatory test for Rocky Mountain spotted fever?
The test used to confirm the presence of Rocky Mountain spotted fever is the in indirect immunofluorescence antibody (IFA) test. To conduct this test, two samples of your dog’s blood will be required, one which is obtained at the time of illness and second blood sample taken 1 to 3 weeks later. The diagnosis is made on the basis of increase in production of antibodies between the first and second samples. In the first sample, the antibody titer would still be low because the infection would be in the initial stages. However, in the second samples the antibody titer would be much higher, a fourfold rise in antibody levels supports the diagnosis (Merck).
A PCR blood test can find the bacteria very early in the illness, but it often turns negative later, so a negative PCR doesn’t rule RMSF out (Merck).
Treatment options for Rocky Mountain Spotted Fever in dogs
The primary treatment for RMSF involves the antibiotic Doxycycline or Tetracycline administered over a period of two to three weeks. Doxycycline is generally administered for 7 to 20 days depending on the dose administered. While tetracycline is administered for a period of 14 to 21 days. Doxycycline is the usual first choice. Your vet will pick the drug and dose for young puppies and pregnant dogs (VCA). Depending on the severity of the case, your dog may or may not require hospitalization. Your dog may also need corticosteroids to reduce any inflammation which may have occurred.
Most dogs start to respond to the treatment within 1 to 2 days. The sooner the treatment is started, the better the chances of recovery of your dog. If this disease is left untreated or ignored, it can be fatal to your dog.
Your dog may need hospitalization if he or she is showing lethargic behavior along with loss of appetite. Hospitalization may also be needed if the dog is showing signs of organ failure, or if supportive therapy is needed like administration of intravenous fluids. Once your pup becomes stable, he or she will be discharged and the rest of the treatment can be continued at home.
Prevention of Rocky Mountain Spotted Fever
As it has previously been said, prevention is better than cure. Now that you know the months when the ticks are most active, be very careful during those months and follow the following instructions to keep ticks away from your dogs
Keep your house, furniture, dog shed, garage as well as yard tick free. You can use pesticides for this. However, consult with the veterinarian regarding which pesticide is safe for use around your dog. For in house cleaning, you can use diatomaceous earth the details of which I have discussed previously.
- Keep your dog on a tick preventive your vet recommends (a chew, spot-on or collar) all year round. This is the most important step.
- Regularly bathe your dog in an anti-tick shampoo
- Check your dog for ticks after every walk, especially around the ears, neck, armpits and between the toes.
- Skip homemade tick sprays and collars. Most use essential oils, which can irritate or poison dogs and don’t reliably stop ticks.
If you observe a tick on your dog’s fur, be very cautious while pulling it out. Always wear a pair of latex gloves before you go anywhere near the tick as there is a chance that the tick might bite you as well. Use fine-tipped tweezers to grasp the tick as close to the skin as you can and pull upward with steady, even pressure. Don’t twist or jerk it. If the mouthparts stay in the skin, leave them alone and let the skin heal. Don’t use nail polish, petroleum jelly or heat to make the tick let go (CDC).
 Is there a chance that humans may get affected by this disease?
If your dog gets infected by the Rocky Mountain spotted fever from a tick, your dog will not be able to pass it to you or any human. However, if the tick that is carrying the causative organisms Rickettsia, infects the dog and then goes and bites the human, then the person can get infected with Rocky Mountain spotted fever just like their dog. According to Centers for Disease Control and Prevention (CDC), RMSF is considered as one of the deadliest tick diseases in America. The treatment model for humans is pretty similar to the one used in dogs. Again, if the disease is left untreated, it can become fatal for humans as well
Some final thoughts
As dog guardians we always worry about our kids. With RMSF there is one more thing to remember: the ticks that infected your dog can bite you too. Your dog can’t pass the disease to you directly, but the same ticks are a risk to your whole family. Thus, keeping ticks out of your life should be of top priority. Has your dog ever suffered from a tick bite? What did you do? What was your veterinarian’s advice and the treatment plan? Let me know in the comment section below. If there is any dog care story or anecdotes you wish to share with everyone, feel free to contact me on my social media channels. I will be happy to share your story with the world.
 See you in my next blog post
Shruti
