RMSF

Question
I have an 8 yr old Doberman/Rottweiller mix that has displayed severe tick born disease symptoms for about 2 months and was finally diagnosed with RMSF 5 days ago. She had shown positive response to Doxycycline a few weeks ago after a 14 day regimen but then a week later developed increasing ataxia and weakness along with hemorrhage from the nares.  Lab reuslts showed thrombocytopenia and greatly elevated WBC's (I don't have the diff results).  She is now showing no positive response to the Doxy so we have started her on Chloramphenical.  Is this a drug that has shown positive results?  She is also showing antiplatelet antibodies.  Would an immunosuppressent be in order?  Thank you for any help you can supply.

Answer
The RMSF has probably brought on an auto-immune crisis.  Normally Doxycyline at a dose of 5 mg per pound twice a day WITH FOOD is given for Lyme Disease and I would also use this high dose for RMSF, and treat for 1 month.   I have never used Choloramphenicol so I can not comment on the drug but it is reported to be effective against RMSF.

Usually the first line of treatment for auto-immune disease is prednisone, however, any immuno-suppressant can worsen the infectious disease.  But in this case, if her platelet counts are dangerously low (less than 50,000) you do not want to wait as she will be in danger of internal bleeding.

Here is a website that explains a lot about RMSF....

www.vet.uga.edu/VPP/clerk/otis