Rocky Mountain Spotted Fever (RMSF) is a common tick-bourne disease. It affects both dogs and humans. According to petMD.com, “It belongs to a class of diseases known as Rickettsia: rod-shaped microorganisms that resemble bacteria, but which behave like viruses, reproducing only inside living cells. Rickettsia rickettsii – the organism responsible for Rocky Mountain Spotted Fever — lives parasitically in ticks and is transmitted by bite to vertebrate hosts.”
Most cases of RMSF are seen in the Southeast, Midwest, Plains and Southwest regions of the United States, but cases have appeared outside of these regions. Ironically, the Rocky Mountain region, where the disease was first discovered, accounts for only a small percentage of RMSF cases.
It should be noted that RMSF coincides directly with the warmer months, April through September. Its primary carriers are rodents and dogs. The disease is transmitted to your dog when the affected tick, either an American dog tick or the Rocky Mountain spotted fever tick, attaches and bites him.
What are the Symptoms of Rocky Mountain Spotted Fever?
There are two stages of RMSF, states web-dvm.net: Subclinical and acute.
“In the subclinical stage, dogs are infected, but do not show outward signs of the disease though they may have laboratory test abnormalities. These dogs may recover quickly. In the acute stage, dogs may have a variety of clinical signs, which can mimic many other diseases. These include:
Loss of appetite
Pain in the muscles and joints
Swollen lymph nodes
Edema (fluid accumulation) in the face and legs
“Some dogs develop pneumonia or heart arrhythmias, which can lead to sudden death. Some dogs have gastrointestinal signs such as vomiting and diarrhea. Most dogs have neurological signs (dizziness, depression, stupor, seizures) and these can sometimes become very severe. Most dogs develop hemorrhages in the retina of the eye, and may also have blood in the stool or nose bleeds. Renal failure can occur. Most of these signs appear two to 14 days after the tick bite.”
How is Rocky Mountain Spotted Fever Diagnosed?
You will need to give your vet a thorough history of your pet’s health. This includes recent activities, any symptoms your dog may be presenting and incidents that may have an effect on how your dog got RMSF. This will help your vet determine which organs could be affected.
German Shepherds and English Springer Spaniels tend to be more severely affected by this disease than other breeds, so it is especially important to give your vet a detailed history if you have one of these dogs.
Your vet will administer blood tests and a biopsy to determine how bad the infection is and how far it has spread throughout your dog’s body.
Your vet will first test your dog’s antibody level. Antibodies are the proteins used to fight off infection, so your vet will look for a change in these levels. This is actually two tests spread two weeks apart, says peteducation.com. The results are then compared. An active infection will show a significant rise in the amount of antibodies present.
The biopsy is used to test the antigen (protein parts) levels of the R. Rickettsii. Your vet will take a small sample of the skin at the bite site to be tested. This test will reveal if your dog is positive for RMSF within four days of being bitten.
Peteducation.com states, “Dogs with Rocky Mountain Spotted Fever will have a low white blood cell count early in the course of infection, and then the cell numbers may increase. During the most severe phase of the disease, the white blood cell counts may again drop, along with the red blood cell counts and platelet numbers. Other organs may be damaged, so liver enzymes and kidney function tests may be at abnormal levels.”
How is Rocky Mountain Spotted Fever Treated?
According to petMD.com, treatment usually involves a hospital stay for your dog, so he can be monitored by a health care team until he improves as this disease can be fatal if not treated right away.
“If your dog is found to have low red-blood cell counts, a condition known as anemia, or if there is a threat of developing a condition known as thrombocytopenia, where the platelets or substances in the blood become too low, a blood transfusion may be necessary to prevent these conditions from becoming life threatening. Your veterinarian will also monitor the amount of fluid in the dog’s brain to prevent edema, or excessive swelling of tissues in the brain, body and lungs.”
Your dog will also be given two antibiotics, doxycycline and enrofloxacin, for 10-14 days.
Peteducation.com states, “Some dogs can develop severe disease and must be treated for shock or severe nervous system symptoms. If treated within the first several days, most dogs will recover completely – some dogs actually show improvement within hours of starting the antibiotics. Dogs who have severe damage to their nervous systems may not recover completely.”
Can I Prevent My Dog from Getting Rocky Mountain Spotted Fever?
Yes, it is possible to keep your dog from getting RMSF. PetMD.com recommends that if you know your dog will be in an area that is tick infested, you take the following precautions.
Use tick repellents and collars
Give your dog a thorough pat-down by checking your his skin and hair for the presence of ticks
Since rodents are a carrier, rodent control is imperative
If you should find a tick(s), use latex gloves to remove it. Make sure you remove the mouth part of the tick.
If taken care of right away, your dog’s prognosis for a full recovery is very good. Take your dog to the vet for another check-up. Your vet may recommend dips and sprays to help prevent further tick infestation. However, if left untreated, your dog could suffer long-term health consequences and may even die as the effects on the nervous system are devastating. This could occur within hours of being bitten.
There is no vaccine for RSMF, but peteducation.com states that dogs who have had RMSF, and made a full recovery, are immune to reinfection for years.
Find A Vet HOW TO articles are intended for informational purposes only. You should always consult with your veterinarian about any health issues affecting your dog.