The short version
Bleeding disorders may be present at birth (congenital) or occur later (acquired). Defects in blood clotting proteins usually show up as delayed bleeding and bruising deep in tissues, while platelet defects usually show up as superficial small bruises, nosebleeds, black stools caused by bleeding into the bowels, or prolonged bleeding at injection and surgery sites.
Abnormal clotting (also called hypercoagulation) leading to blocked arteries may be inherited disorders of anticlotting proteins or acquired disorders. Acquired clotting diseases are more common in animals than are inherited disorders.
Congenital Clotting Protein Disorders
Hypofibrinogenemia (an abnormal shortage of fibrinogen in the blood), accompanied by severe bleeding, has been reported in Saint Bernards and Vizslas. Dysfibrinogenemia (abnormally functioning fibrinogen) has been reported in an inbred family of Russian Wolfhounds (Borzois). Dogs with the disorder had mild bleeding problems (such as nosebleeds), but injury or surgery resulted in life-threatening bleeding. Intravenous transfusion with fresh or fresh-frozen plasma (the liquid portion of blood) is the best treatment to stop the bleeding.
Factor II (prothrombin) disorders are rare. Prothrombin is one of the proteins that plays a role in clotting of blood. Boxer dogs have been reported to have prothrombin that is present in normal amounts in the body but does not function normally. A disorder of Factor II has been reported in English Cocker Spaniels. Signs in affected puppies, such as nosebleeds and bleeding gums, decrease with age. Adults bruise easily or have inflamed skin. Treatment is by transfusion of whole blood or plasma.
Deficiency of Factor VII, another clotting protein, has been reported in Beagles, English Bulldogs, Alaskan Malamutes, Alaskan Klee Kai, Miniature Schnauzers, Boxers, and mixed-breed dogs. Usually, it is not associated with sudden, unexplained bleeding, but affected dogs may have bruising or excessive bleeding after surgery. Prolonged bleeding after giving birth has been reported. Factor VII deficiency is most often diagnosed coincidentally when clotting tests are performed.
Acquired Clotting Protein Disorders
Most clotting proteins are produced in the liver. Therefore, liver disease can lead to decreased levels of clotting proteins, particularly Factors VII, IX, X, and XI, and proteins that break up clots. Severe liver disease can also lead to a condition known as disseminated intravascular coagulation (see below). Fibrinogen, the protein in blood that is made in the liver and converted to fibrin in response to tissue damage, and von Willebrand’s factor, which is produced outside the liver and helps platelets stick to the blood vessel wall and to each other, can be increased in liver disease.
Dogs that eat rat poison may have blood clotting problems because the poison reduces the liver’s production of clotting proteins. Affected animals may have blood clots and bruising of superficial and deep tissues. Often, the animals do not bleed within the first 24 hours after eating the poison. Vitamin K1, given by injection and then by mouth, is the usual treatment, but may cause side effects, including anemia or allergic reactions. If you suspect your dog has eaten any type of rat or mouse poison, this is an emergency and an immediate trip to your veterinarian is appropriate.
Platelet Disorders
Disorders of platelets include having too few platelets (thrombocytopenia) or having platelets that do not work properly. Each type of disorder can be either congenital (present at birth) or acquired later in life. Thrombocytosis is having too many platelets. It may occur as a response to a physiologic or disease process, or, rarely, it may be a component of blood cancer.
Congenital Thrombocytopenia
Gray Collies may develop a disorder called cyclic hematopoiesis (see ), which is characterized by 12-day cycles during which all types of blood cells, including platelets, decrease. All cell types are affected, but neutrophils (the most common type of white blood cells) are most affected. Mild to severe platelet shortages can be seen, and excessive bleeding is a potential complication. This disorder is deadly; most dogs with the disease die from infections before 6 months of age. Even dogs that receive frequent antibiotic treatments usually die by 3 years of age from amyloidosis, a condition in which abnormal proteins build up in the body’s organs. Treatment with proteins that stimulate the production of neutrophils in the bone marrow may provide temporary—but not longterm—improvement.
Hereditary macrothrombocytopenia occurs in about 50% of Cavalier King Charles Spaniels. These dogs have a decreased number of platelets with the presence of giant platelets. This benign (harmless) condition is discovered on routine blood screens.
Acquired Thrombocytopenia
Acquired thrombocytopenias are common in dogs. Many causes have been identified, most involving the immune system destroying platelets.
Rickettsial diseases, caused by organisms in the genera Ehrlichia and Anaplasma, cause mild to severe loss of platelets in dogs. Infection may include short- and longterm changes in the number of platelets and other blood cells. Ticks are the usual carriers of the infection. Infected dogs may show no signs or may have nosebleeds, bleeding into the bowels (resulting in black stools), bleeding of the gums, and prolonged bleeding after vaccination or surgery.
Thrombocytopenia due to immune system dysfunction occurs when the immune system makes antibodies that destroy platelets or platelet-producing cells in the bone marrow. Signs include tiny, purplish red spots on the gums or skin (called petechiae), bruising, bleeding into the bowels resulting in black stools, or nosebleeds. An evaluation of the bone marrow may be necessary to help determine if circulating platelets or the platelet-forming cells are targeted by the antibodies. Corticosteroids are the usual treatment, although other drugs are sometimes used. A blood transfusion may be necessary for anemic dogs. Affected animals should rest to help prevent injuries and abnormal bleeding. If an animal has repeated episodes of the disease, the spleen is sometimes removed.
Frequently asked questions
Bleeding disorders dogs?
The Merck Veterinary Manual covers this in the article linked on this page. Bleeding disorders may be present at birth (congenital) or occur later (acquired). Defects in blood clotting proteins usually show up as delayed blee… If your dog is unwell, contact your veterinarian — this page is educational, not a diagnosis.
Clotting disorders dogs?
The Merck Veterinary Manual covers this in the article linked on this page. Bleeding disorders may be present at birth (congenital) or occur later (acquired). Defects in blood clotting proteins usually show up as delayed blee… If your dog is unwell, contact your veterinarian — this page is educational, not a diagnosis.
Blood disorders dogs?
The Merck Veterinary Manual covers this in the article linked on this page. Bleeding disorders may be present at birth (congenital) or occur later (acquired). Defects in blood clotting proteins usually show up as delayed blee… If your dog is unwell, contact your veterinarian — this page is educational, not a diagnosis.