Use of real-time polymerase chain reaction to monitor antibiotic therapy in a dog with naturally acquired Mycoplasma haemocanis infection

Mycoplasma haemocanis is a hemotropic bacterium that can be associated with acute hemolytic disease in immunocompromised or splenectomised dogs. This case report describes, for the first time, the use of real-time quantitative polymerase chain reaction to monitor M. haemocanis infection in a splenectomised dog. This report also describes the application of real-time quantitative polymerase chain reaction for the analysis of deoxyribonucleic acid extracted from stained blood films. The analysis of blood films from the time of initial presentation allowed a retrospective confirmation of M. haemocanis infection. M. haemocanis copy numbers remained high throughout antibiotic treatment of this dog. A decline in copy numbers was only recorded after 11 months of therapy, when improvements in clinical and haematological indices were also noted. Clearance of infection was not achieved and the dog remained positive for M. haemocanis at 3½ months post-cessation of antibiotic therapy. Cytological examination of blood films for the presence of organisms was insensitive for the detection of parasitemia.