Page 1373 - Small Animal Internal Medicine, 6th Edition

CHAPTER 82 Anemia 1345

TABLE 82.2
VetBooks.ir Interpretation of Morphologic RBC Abnormalities in Cats and Dogs

MORPHOLOGIC
ABNORMALITY COMMONLY ASSOCIATED DISORDERS

Macrocytosis Regeneration, breed-related feature (Poodles); FeLV infection; dyserythropoiesis (bone
marrow disease)
Microcytosis Iron deficiency; breed-related characteristic (Akita, Shar Pei, Shiba Inu); portosystemic
shunt or microvascular dysplasia; PRCA; polycythemia (erythrocytosis); inflammation
Hypochromasia Iron deficiency
Polychromasia Regeneration
Poikilocytosis Regeneration; iron deficiency; hyposplenism
Schistocytosis (fragments) Microangiopathy; hemangiosarcoma; DIC; hyposplenism
Spherocytosis IHA; hemophagocytic malignant histiocytosis; babesiosis; zinc toxicity
Acanthocytosis (spur cells) Hemangiosarcoma; lymphoma; other malignancies; liver disease; hyposplenism
Echinocytosis (burr cells) Artifact; renal disease; pyruvate kinase deficiency anemia
Elliptocytosis Congenital elliptocytosis (dogs)
Heinz bodies Oxidative insult to RBCs
Howell-Jolly bodies Regeneration; hyposplenism
Autoagglutination IHA
Metarubricytosis Breed-related characteristic (Schnauzer, Dachshund); extramedullary hematopoiesis;
regeneration; lead toxicity; hemangiosarcoma
Leukopenia See text.
Thrombocytopenia See text.
Pancytopenia Bone marrow disorder; hypersplenism

DIC, Disseminated intravascular coagulation; FeLV, feline leukemia virus; FIV, feline immunodeficiency virus; IHA, immune hemolytic anemia;
PRCA, pure red cell aplasia; RBC, red blood cell.
Modified from Couto CG et al.: Hematologic and oncologic emergencies. In Murtaugh R et al., editors: Veterinary emergency and critical
care medicine, St Louis, 1992, Mosby.

Dogs with high reticulocyte counts and microcytosis/ MANAGEMENT OF THE
hypochromasia typically have IDA. ANEMIC PATIENT
The following points generally hold true:
The first basic principle of the management of anemic (or
1. If the RBC indices are macrocytic and hypochromic, bleeding) patients is to collect all blood samples before insti-
the anemia is most likely associated with the presence tuting any therapy. Because the condition in most of these
of high numbers of reticulocytes, which are larger and patients may constitute a true emergency at the time of pre-
contain less Hb than mature RBCs. Therefore the anemia sentation, samples often are not collected until the patient
is likely regenerative. However, >85% of regenerative has been completely stabilized, resulting in treatment-
anemias are normocytic normochromic or normocytic induced changes in hematologic or serum biochemical
hypochromic. values.
2. If the reticulocyte count is higher than 120,000/µL (or
≈4%) and the anemia is mild to moderate, the anemia is
likely regenerative. REGENERATIVE ANEMIAS
3. As part of the evaluation of a patient with regenerative Blood Loss Anemia
anemia, it is beneficial to determine the serum or plasma Acute blood loss in otherwise normal dogs and cats results
protein concentration because blood loss usually results in reticulocytosis (regeneration) within 48 to 96 hours.
in hypoproteinemia and hemolysis does not. Other phys- Therefore animals evaluated shortly after a traumatic injury
ical examination and clinicopathologic findings that help and severe blood loss usually have a nonregenerative anemia
distinguish blood loss from hemolytic anemias are listed with a low to normal serum (plasma) protein concentration.
in Table 82.3. The source of bleeding should be identified and the bleeding