Page 507 - Problem-Based Feline Medicine

23 – THE BLEEDING CAT 499

Differential diagnosis Clinical signs

In most cases the cat with liver disease is presented for Clinical bleeding is uncommon except with severe
subacute to chronic non-specific signs and coagulopa- thrombocytopenia, in which case bleeding is typical of
thy is identified in the work-up of liver disease. platelet disorders, e.g. petechiation, epistaxis, melena,
prolonged bleeding after venepuncture.
A large number of disorders may be associated with
subacute non-specific signs and subclinical coagulopa- Diagnosis
thy, including neoplasia, retroviral infections, FIP, heart
disease and pancreatitis. Routine work-up will help FeLV antigen test.
identify the primary disease. ● Bleeding tendencies are most likely to occur dur-
ing persistent viremia, in which case ELISA and
FA tests are usually both positive.
Treatment
● If peripheral blood tests are negative and another
Vitamin K1, 2.5–5 mg/kg SC for 1–2 days, will usually cause of megakaryocytic hypoplasia has not been
normalize PT and aPTT in 1–2 days if vitamin K determined, obtain a FA or PCR test on a bone mar-
deficiency is solely responsible for coagulopathy. row aspirate or ELISA test on a bone marrow core
(PIVKA values take 3–5 days to normalize.) The biopsy. It should be noted that PCR testing has
need for further vitamin K1 therapy will depend on suc- not been standardized and is more likely to give
cess of managing the primary disease. false-positive results than ELISA and FA if the
laboratory does not maintain the highest stan-
dards of quality control.
Prognosis
Hemostatic testing may reveal thrombocytopenia, and
Prognosis is determined by the primary liver disease.
prolonged PT, ACT, and aPTT and hypofibrinogenemia
Prognosis for resolution of a vitamin K deficient state if DIC is present.
is excellent.
Differential diagnosis

The main cause of clinical bleeding in FeLV-infected
FELINE LEUKEMIA VIRUS (FELV) cats is megakaryocytic hypoplasia. If a FeLV-positive
INFECTION** cat is bleeding without severe thrombocytopenia
9
(usually platelets < 20 × 10 /L, <200 000/μl), another
Classical signs hemostatic disorder should be investigated.
● Lethargy, inappetence, weight loss, A concurrent disease may be responsible for sub-
unkempt haircoat, fever, anemia, gingivitis, clinical hemostatic defects including liver disease,
recurrent upper respiratory infections, cardiomyopathy, pancreatitis, renal failure, other sys-
opportunistic infections. temic infections, lymphoma and other neoplasms, and
● Cats with megakaryocytic hypoplasia may snakebite envenomation and other toxicoses.
have platelet disorder type bleeding. Feline immunodeficiency virus (FIV) infection
causes similar signs to FeLV infection and may also
See main reference on page 540 (The Anemic Cat). cause megakaryocytic hypoplasia and other hemosta-
tic defects. An FIV test may be used to rule this out.
Pathogenesis Most causes of megakaryocytic hypoplasia, ITP and
DIC may be identified by routine work-up.
FeLV infection can cause bleeding tendencies by
several mechanisms. These include: Treatment
● Megakaryocytic hypoplasia.
● Immune-mediated platelet destruction. Thrombocytopenia and other hemostatic defects may
● DIC secondary to infections and neoplasia. be transiently improved by transfusion of fresh