IMHA in dogs secondary to Babesia gibsoni diagnosed at TVMDL
Written by Dr. Julie Piccione, Clinical Pathology Section Head
With over 800,000 tests run annually, TVMDL encounters many challenging cases. Our case study series will highlight these interesting cases to increase awareness among veterinary and diagnostic communities.
Immune-mediated hemolytic anemia (IMHA) is a common disorder in dogs where red blood cells are destroyed after being coated with antibodies and/or complement. IMHA can occur as a primary (idiopathic) process or secondary to a variety of etiologies (e.g. infectious agents and neoplasia). IMHA is a dangerous disorder that leads to severe clinical disease and is associated with a high mortality rate.
The clinical pathology laboratory at TVMDL often receives blood samples for Coombs testing, a direct antiglobulin test that can support the diagnosis of IMHA. Over the last few months, multiple samples for Coombs testing came from young to adult Pit Bull dogs with CBC data suggestive of IMHA. Evaluation of blood smears at TVMDL revealed numerous organisms consistent with Babesia gibsoni (see image), which were later confirmed by PCR. Babesia gibsoni is most commonly observed in pit bull terriers and greyhounds and infections are reported in several states throughout the US.
IMHA is suspected when compatible CBC findings are observed, such as a marked regenerative anemia, hemoglobin:HCT mismatch, macroagglutination, and leukocytosis. Evaluation of a blood smear at a diagnostic laboratory is an essential part of the clinical work-up for any sick patient to identify infectious agents and neoplastic cells, and to evaluate cellular morphology. Identification of Babesia gibsoni as the causative agent of the IMHA in these cases allowed for appropriate and rapid treatment.
To learn more about this case, contact Dr. Julie Piccione, Clinical Pathology Section Head at the College Station lab. For more information about TVMDL, call 1.888.646.5623 or visit tvmdl.tamu.edu.
Peripheral blood smear from a dog with IMHA secondary to Babesia gibsoni. The image shows anemia, thrombocytopenia, and numerous small Babesia gibsoni organisms within RBCs (some noted with arrows).