Page 1431 - Small Animal Internal Medicine, 6th Edition

CHAPTER 87 Disorders of Hemostasis 1403

TABLE 87.6 BOX 87.6
VetBooks.ir Hemostatic Abnormalities* DOGS (%) CATS (%) Treatment of Dogs and Cats With Disseminated
Intravascular Coagulation
ABNORMALITY
1. Eliminate the precipitating cause.
Thrombocytopenia 90 57 2. Halt intravascular coagulation:
Prolonged aPTT 88 100 Heparin
Schistocytosis 76 67 • Minidose: 5-10 IU/kg SC q8h
Positive FDP 64 24 • Low dose: 50-100 IU/kg SC q8h
• Intermediate dose: 300-500 IU/kg, SC or IV, q8h
Prolonged OSPT 42 71 • High dose: 750-1000 IU/kg, SC or IV, q8h
Hypofibrinogenemia 14 5 Blood or blood products (provide AT, other anticoagu-
lants, and clotting factors)
aPTT, Activated partial thromboplastin time; FDP, fibrin degradation 3. Maintain parenchymal organ perfusion:
product; OSPT, one-stage prothrombin time. Aggressive fluid therapy
*In 50 dogs and 21 cats with disseminated intravascular 4. Prevent secondary complications:
coagulation (DIC) evaluated at The Ohio State University Veterinary Oxygen
Teaching Hospital. Correction of acid-base imbalance
From Couto CG: Disseminated intravascular coagulation in dogs
and cats, Vet Med 94:547, 1999. Antiarrhythmics
Antibiotics

whereas the presence of FDPs and hypofibrinogenemia were AT, Antithrombin.
rare.
Estrin et al. (2006) have described clinical and clinico-
pathologic findings in 46 cats with DIC. Spontaneous bleed- Of note, if blood and blood products were available in
ing was present in 15% of the cats; 43 of 46 cats died or were an unlimited supply, as is the case in most human hos-
euthanized. The most common underlying disorders were pitals, small animal patients with DIC would not die of
lymphoma, other forms of neoplasia, pancreatitis, and sepsis. hypovolemic shock. Most dogs with DIC die of pulmonary
The median PT of nonsurvivors was more prolonged than in or renal dysfunction. At our clinic, so-called DIC lungs
survivors (P = 0.005). DIC in cats can result from a variety (i.e., intrapulmonary hemorrhages with alveolar septal
of neoplastic, infectious, and inflammatory disorders and is microthrombi) appear to be a common cause of death in
associated with a high case fatality rate. these patients.
Treatment Halting Intravascular Coagulation
Once a diagnosis of DIC has been established, or even if the I use a dual approach to halt intravascular coagulation—the
degree of suspicion is high that DIC is present, treatment administration of heparin and blood or blood products. As
should be instituted without delay. Unfortunately, no con- noted, heparin is a co-factor for AT and therefore is not
trolled clinical trials have been performed in veterinary effective in preventing the activation of coagulation unless
medicine evaluating the effects of different treatments in AT activity in the plasma is sufficient. Because AT activity
dogs or cats with DIC, so this discussion reflects my personal in animals with DIC is usually low as a result of consump-
recommendations for the treatment of dogs with this dis- tion and possibly inactivation, the patient should be pro-
order (Box 87.6). vided with sufficient quantities of this anticoagulant. The
Unquestionably, removing or eliminating the precipitat- most cost-efficient way of achieving this is to administer
ing cause constitutes the main therapeutic goal in patients FFP. The old adage that administering blood or blood prod-
with DIC, but this is not always possible. Conditions in ucts to a dog with DIC is analogous to “adding logs to a
which the precipitating causes can be eliminated or amelio- fire” has not been true, in my experience. Therefore blood
rated include a primary HSA (surgical excision), dissemi- or blood products should never be withheld based solely
nated or metastatic HSA (chemotherapy), sepsis (appropriate on this.
antimicrobial treatment), and IHA (immunosuppressive Heparin has been used historically to treat DIC in
treatment). In most other situations (e.g., electrocution, heat humans and dogs. However, controversy still exists re-
stroke, pancreatitis), the cause can rarely be eliminated garding whether it is beneficial. In my experience, the
within a short time. Therefore the treatment of dogs with survival rate in dogs with DIC seems to have increased
DIC is aimed at the following: since I started using heparin and blood products. Al-
though this can also be attributed to improvement in
• Halting intravascular coagulation patient care, I believe that heparin is beneficial in such
• Maintaining good parenchymal organ perfusion patients and indeed may be responsible for the increased
• Preventing secondary complications survival rate.