Clinical Pathology for Exotic Small Mammals

Key Points

  • Approximately 0.5 to 1.0 ml of blood may be safely collected per 100 grams of body weight.
  • White blood cell counts for most mammals fall between 5,000 to 15,000 cells/µl, however white cell counts for rabbits and geriatric ferrets are generally lower, measuring 4,000 to 10,000 cells/µl and 3,000 to 6,000 cells/µl ,respectively.
  • Rabbits have heterophils instead of neutrophils. These polymorphonuclear white blood cells possess many pink or red cytoplasmic granules.
  • When interpreting the differential, first determine the primary leukocyte for that species. Lymphocytes predominate in some small mammals like the rabbit.
  • When challenged with a bacterial infection, rabbits and ferrets sometimes display a shift in the heterophil/neutrophil:lymphocyte ratio, often without an overall increase in leukocytes.
  • The most common cause of hypoglycemia in ferrets is insulinoma.
  • Calcium levels may be elevated in normal rabbits fed high calcium (i.e. alfalfa-based) diets.

Small mammals, such as rabbits and rodents, are stoic by nature and have evolved to mask their illness to avoid predation. This behavior can create a false sense of security in owners and a clinical challenge for veterinarians. In some cases, an animal that appears clinically normal may in fact have a terminal illness. Use hematology and biochemistry analysis to characterize the true physiological status of these species and aid in disease diagnosis . . .

To continue you need to be a member. (Français), (Español)

Pour continuer, vous devez être un membre

Para continuar, debe ser miembro de

Already a LafeberVet Member?

Please Login


Fudge AM. Laboratory Medicine: Avian and Exotic Pets. St. Louis: WB Saunders, 2000.

Mitchell M. Clinical pathology for exotic small mammals. Proc CVC 2009.

Mizoguchi Y, Matsuoka T, Mizuguchi H, et al. Changes in blood parameters in New Zealand White rabbits during pregnancy. Lab Anim 44(1):33-39, 2010.

Lester VK, Tarpley HL, Latimer KS. Small mammal hematology: Leukocyte identification in rabbits and guinea pigs. Available at Accessed on January 6, 2010.

Quesenberry KE, Carpenter JW. Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery. WB Saunders. St. Louis: WB Saunders, 2003; 147-154.