A variety of diagnostic tests may be indicated in any individual situation. The following are each considered essential for the diagnosis of the cause of abnormal bleeding: Complete history and physical examination. Your veterinarian will look for evidence of bleeding in the eyes and on the gums, as well as bruises on the skin.
A complete blood count (CBC) is always indicated in a bleeding animal. In this test a small amount of blood is withdrawn from the pet, and the cells of each type in the blood are counted. Not only does it allow quantification of the number of platelets, the cells that allow the blood to clot, but it also shows how serious the blood loss has been by revealing how many red blood cells are left.
Other test will likely be indicated as well. Which of these tests is appropriate for an individual animal will be determined after the veterinarian has completed the initial examination, and perhaps after results of the CBC become available.
Abnormal bleeding can be due to abnormal coagulation, or alternatively, to local disease. For instance, nosebleeds may be due to abnormal coagulation or to disease of the nasal passages themselves. Expect your veterinarian to try to determine if all the bleeding is coming from one site. If so, they may order tests to examine that site, including radiographs (X-rays) or biopsies.
If platelet numbers are low, titers for infectious diseases may be indicated. Certain types of infection are particularly likely to result in low platelet numbers. The veterinarian may take blood to measure antibodies to that infection. Antibodies are part of the immune response to germs, and their presence shows that the pet has been exposed to the germ in question.
Unfortunately, there are no good tests for one of the most common causes of low platelets, immune-mediated thrombocytopenia. Immune-mediated thrombocytopenia results from an immune system attack on the blood platelets. There are a few tests that attempt to measure this attack, but none are perfect tests. In each, a small amount of blood is withdrawn and subjected to special assays in the laboratory.
Bone marrow aspiration/biopsy may be indicated. The bone marrow is the soft red tissue found inside hard bones and is here that most blood cells are made by the body. If the platelet count is low, your veterinarian may perform a procedure in which a large needle is inserted through the hard bone into the soft center, and a small amount of marrow is removed for examination under the microscope. Both local anesthetic and sedation are usually administered to minimize discomfort during the procedure.
A buccal mucosal bleeding time may be indicated to evaluate platelet function, especially if von Willebrand's disease is suspected. A small cut is made on the gums, and the time required for a clot to form is measured.
In cases where the suspicion of von Willebrand's disease is strong, a blood sample is sent off to a special laboratory for measurement of the von Willebrand's factor.
Effective coagulation factor concentration may be measured by performing one of several tests. Examples include activated coagulation time (ACT), activated partial thromboplastin time (aPTT), one stage prothrombin time (OSPT). In each of these tests, a small amount of blood is collected in a special tube, blood clotting is activated artificially, and the time required for the blood to clot is measured.
If hemophilia is suspected, blood samples may be collected and sent off to a special lab to have the concentration of soluble coagulation factors measured.
If DIC is suspected, fibrin degradation products may be measured. In this test, a small blood sample is withdrawn to quantify the byproducts of clot lysis.
One or more of the diagnostic tests described above may be recommended by your veterinarian. In the meantime, treatment of the symptoms might be needed, especially if the problem is severe. The following nonspecific (symptomatic) treatments may be applicable to some pets with bleeding disorders. These treatments may reduce severity of symptoms or provide relief for your pet. However, nonspecific therapy is not a substitute for definite treatment of the underlying disease responsible for your pet's condition.
If ongoing blood loss from a single site can be stopped, it will be. For instance, the nose might need to be packed with gauze if nosebleed is severe.
If your cat has lost a lot of blood, a transfusion of either red blood cells, or whole blood (red blood cells plus the liquid plasma) may be indicated regardless of the cause of bleeding. This requires administration of the transfused blood through an intravenous catheter while the pet is in the hospital.
Transfusion of either plasma (the liquid portion of the blood) or fresh whole blood provides soluble clotting factors, and may be initiated before a definitive diagnosis is obtained.
If there are not enough blood platelets, treatment will be geared to likely causes. Unfortunately, transfusion of platelets themselves is not particularly effective. Because immune-mediated disease and certain infectious diseases are frequent causes of a severe decrease in platelet numbers, treatment may be begun while waiting for test results. The most common treatments are with corticosteroids like prednisone or dexamethasone) to suppress the immune system, or with antibiotics such as tetracycline) for the more important infectious causes of thrombocytopenia.
If your cat is suspected of having von Willebrand's disease, a condition in which a substance that helps the platelets stick together is deficient, the animal may be treated with a plasma transfusion, and possibly also with medication designed to increase release of the deficient factor.
If your cat is suspected of having ingested a toxin that interferes with the ability of the coagulation factors to work, such as warfarin-related rat poison, the animal may receive vitamin K either with or without an accompanying transfusion. Because bleeding after exposure to warfarin can be very severe, the veterinarian may choose to administer vitamin K before a definitive diagnosis has been reached.
Other causes of coagulation factor deficiency, such as hemophilia or liver failure, may temporarily respond to plasma transfusion.
Treatment of DIC depends on elimination of the underlying disease, plus the administration of transfusions and drugs like heparin designed to stop the vicious cycle of blood clotting and clots breaking up.