TABLE 65-3.

Morphological and Functional Disorders of Canine and Feline Leukocytes

DISORDER	INHERITANCE	CAUSE	SPECIES	APPEARANCE/CLINICAL SIGNS	DIAGNOSIS	TREATMENT	REFERENCES
Cyclic hematopoiesis	Autosomal recessive	Stem cell abnormality	Gray-coated collie, collie- mix dogs	Continuous abnormal hematological cycles Decreased neutrophil number and function: recurrent bacterial infections, defective platelet aggregation, systemic amyloidosis	Serial CBCs every 3-6 weeks: cyclic neutropenia and anemia Clinical signs: hair coat color dilution	Broad-spectrum antibiotics for sepsis Lithium carbonate 21-26 μg/kg/day PO (potential side effects) rhG-CSF 5 μg/kg SC BID (watch for neutralizing antibodies) Bone marrow trans-plantation is curative	Campbell (1985), Lothrop et al. (1988), Niemeyer and Lothrop (2000)
Inherited vitamin B12 (cobalamin) malabsorption	Autosomal recessive	Failure to express intestinal intrinsic factor cobalamin complex receptor (cubilin)	Inbred giant schnauzer	Nuclear chromatin maturation abnormalities, neutropenia, nonregenerative anemia	Decreased serum cobalamin concentration Classic hematological abnormalities	Parenteral administration of megadose cobalamin (1 mg IM) monthly No improvement with oral cobalamin	Fyfe (2000)
Birman cat neutrophil granulation anomaly	Autosomal recessive	Fine azurophilic granules similar to progranulocyte granules	Birman cat	Prominent neutrophil granulation	Serial CBCs Differentiate from MPS VI, MPS VII, and toxic change	None; neutrophils function normally	Hirsch and Cunningham (1984)
Canine leukocyte adhesion deficiency	Autosomal recessive	Deficient expression of CD18 (subunit of B2 integrins)	Irish setter	Recurrent infections, marked neutrophilia, chronic anemia Bone marrow myeloid hyperplasia	Flow cytometry for neutrophil CD18 expression	Antibiotics alleviate signs but not infection Affected animals usually die	Andreason and Roth (2000)
Pelger-Huët anomaly	Uncertain inheritance Acquired secondary to sepsis, drugs, MPD, viral infections	Failure of the mature nucleus to form true filaments	Cats, dogs	Peanut-shaped nuclei in granulocytes, monocytes, or megakaryocytes	Serial CBCs	None; neutrophils function normally
Chédiak-Higashi syndrome	Autosomal recessive	Failure of granule fusion	Persian cats	Yellow-green eyes Smoke-blue hair color Hypopigmentation of eyes, skin, hair	CBC: neutropenia, abnormal granules Prolonged bleeding times Abnormal platelet aggregation	Temporary improvement with rhG-CSF Bone marrow transplant	Meyers (2000)

CBC, Complete blood count; rhG-CSF, recombinant human granulocyte-colony stimulating factor; IM, intramuscularly; MPS, mucopolysaccharidosis; MPD, myeloproliferative disease.