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24 – THE ANEMIC CAT 547

Weakness, tachycardia and pale mucous membranes In dogs, infection may result in either a regenerative or
result from anemia. non-regenerative anemia.
Fever or other evidence of secondary infections Early in infection, acute aplastic anemia occurs
develop if neutropenia is present because of destruction of progenitor and proliferative
cells in the bone marrow. The resulting anemia is usu-
Bleeding results from thrombocytopenia.
ally mild or absent because of the long erythrocyte
lifespan.
Diagnosis
Secondary immune-mediated anemia may occur.
Pancytopenia (aplastic anemia) is most common;
In the chronic phase of the disease, hemopoietic stem
pure red cell aplasia is unusual.
cell injury results in moderate to severe non-regenera-
Lymphoma, myeloproliferative disease or multiple tive anemia.
myeloma are often detected on bone marrow cytology
Cats experimentally infected with Neorickettsia risticii
or biopsy.
develop morulae in mononuclear cells and occasion-
Circulating malignant cells may be detected. ally develop fever, depression, lymphadenopathy,
anorexia and diarrhea.
Differential diagnosis Cats experimentally infected with A. phagocytophilum
develop morulae in neutrophils and eosinophils.
FeLV, drugs or toxins, ehrlichiosis.
Cases proven by genetic sequencing were E. canis
(North America and France) or A. phagocytophilum
Treatment
(Sweden, Ireland, Denmark and North America).
Treat the neoplasm primarily.
Ehrlichia-like morula have been detected in mononu-
Supportive care. clear cells or neutrophils of naturally exposed cats in
the United States, Kenya, France, Sweden, Brazil and
Thailand.
EHRLICHIOSIS AND ANAPLASMOSIS
Other cases have been diagnosed based on the combin-
Classical signs ation of positive E. canis or A. phagocytophilum serol-
ogy, clinical or laboratory findings consistent with
● Lethargy, anorexia, depression and fever.
ehrlichial infection, exclusion of other causes, and
● Lameness from polyarthritis.
response to an anti-rickettsial drug. However, it is
● Pale mucous membranes.
unknown whether these cats were ill from the Ehrlichia
spp. infection.
Transmission
It is unknown how clinically ill, naturally exposed cats
are infected with an Ehrlichia canis-like organism. Clinical signs

Ixodes spp. ticks have been associated with several Cats are usually young and both males and females
cases with Anaplasma phagocytophilum (previously have been affected.
E. equi) infection.
Cats infected by A. phagocytophilum have only been
Exposure to arthropods has been reported in about 30% diagnosed in areas with Ixodes ticks.
of the cases in the literature.
Fever, inappetence, lethargy, weight loss, hyperes-
thesia or joint pain, and pale mucous membranes are
Pathogenesis
the most common abnormalities. Splenomegaly, dysp-
Pathogenesis is unknown, but it is likely similar to dogs nea, uveitis, diarrhea and lymphadenomegaly are also
based on clinical and laboratory findings. detected in some.