Hematology of Cavies

Caviidae is a family of rodents native to South America, which includes domestic and wild guinea pigs along with the capybara, mara, and rock cavy. Blood collection from guinea pigs can be challenging and is a balancing act of determining the blood volume needed for analysis and selecting a vessel or method that will supply the required quantity without threatening the animal's well-being. Guinea pig platelets are typically quite small, with an oval, irregular, or spindle shape and fine purple granulation. Coagulation studies demonstrate that the guinea pig has a longer prothrombin time than other domestic species, and a relatively long partial thromboplastin time. Bone marrow can be obtained from the femur, tibia, or iliac crest in live guinea pigs under general anesthesia. It is difficult to find hematologic studies on cavies which fully comply with the guidelines for reference interval generation set forth by the American Society for Veterinary Clinical Pathology.