Page 544 - Problem-Based Feline Medicine

536 PART 8 CAT WITH ABNORMAL LABORATORY DATA

Pyruvate kinase deficiency has been described in
Classical signs—Cont’d
Abyssinian cats, Somalis and DSH with intermittent,
regenerative anemias. ● Evidence of trauma, neoplasia,
inflammatory or erosive disease.
Increased osmotic fragility of erythrocytes causing
● Melena, hematochezia, hematuria,
hemolytic crises with macrocytic regenerative anemia
dyspnea, hemothorax or hemoabdomen.
and splenomegaly has also been documented in
Abyssinians and Somalis.
Cats with hereditary hemolytic anemias exhibit inter- Pathogenesis
mittent anemia and weight loss, and the clinical signs
Blood vessels are damaged by trauma (blunt trauma,
appear to be ameliorated by splenectomy.
foreign bodies, etc.), erosive diseases resulting from
Porphyria in a family of Siamese cats was associated tumors, chronic infections (fungal in particular), toxi-
with severe macrocytic, hypochromic anemia with cities (mainly gastrointestinal), or vasculitis like sys-
poikilocytosis, Howell–Jolly bodies, and nucleated red temic lupus erythematosus.
blood cells.
Porphyria in domestic shorthair cats is inherited as Clinical signs
an autosomal dominant trait, and is characterized by
Weakness and lethargy are common presenting com-
only a mild anemia.
plaints.
Porphyrins produce a brownish discoloration of teeth,
Blood usually is lost into tissues, spaces like the pleu-
bones (at necropsy), and urine, all of which fluoresce
ral space and peritoneal cavity, the gastrointestinal
bright pink-red with ultraviolet light.
tract (including palate of the cat), or any external dam-
aged tissue like the nose.
Diagnosis Bleeding may or may not be evident, depending on
where the blood is lost.
Measure pyruvate kinase activities.
Melena or hematochezia may be present in cases with
Measure blood porphyria concentrations. Demonstrate
gastrointestinal blood loss; exceptions include small
fluorescence of porphyrins in teeth or urine.
volume, chronic bleeding and acute loss.
Acute dyspnea or weakness associated with pale
Treatment mucous membranes and evidence of hemothorax or
hemoabdomen on centesis are typical findings.
Supportive care including transfusion if indicated.
In contrast to blood loss from coagulopathies or hyper-
Splenectomy for anemias caused by pyruvate kinase
tension, local diseases usually do not result in evidence
deficiency and increased osmotic fragility.
of bleeding at distant sites. The exception is vasculitis.
Fungal and neoplastic diseases of the nose that result in
REGENERATIVE ANEMIA DUE TO epistaxis usually have mucopurulent discharge prior to
BLOOD LOSS development of epistaxis.
Other clinical signs are associated with the primary dis-
LOCAL DISEASES OF BLOOD VESSELS** ease.

Classical signs
Diagnosis
● Anemia.
Diagnostic work-up and findings are dependent on the
● Bleeding internally or externally.
individual primary disease and site of bleeding.