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Glanzmann's Thrombasthenia

Glanzmann's Thrombasthenia: An Overview

Glanzmann's thrombasthenia (GT) is a rare bleeding disorder, or coagulopathy, in which the platelets are defective. An important aspect of platelets is their ability to stick together until clotting and tissue repair occurs. While dogs with GT have normal platelet counts, they have abnormal platelet aggregation and blood clotting and thus are at risk of life-threatening bleeding, including spontaneous hemorrhage and excessive hemorrhage as a result of injury or surgery. GT has been recognized in several breeds, in particular Otter Hounds and Great Pyrenees.

Causes of Glanzmann's Thrombasthenia

GT is an inherited autosomal recessive disorder that is caused by a mutation in the gene encoding for platelet GBIIb (GP stand for glycoprotein.) In GT one or both of these genes are mutated somehow. The mutation causing GT in Otterhounds is Exon 12 while the mutation causing GT in Great Pyrenees is Exon 13.

Preventing Glanzmann's Thrombasthenia

DNA testing can be used to identify dogs that carry or are affected by the gene mutation. These tests can be performed by sending a simple blood test through the mail. Discuss this with your vet if you are considering breeding a dog that may be affected or is a potential carrier.

Symptoms of Glanzmann's Thrombasthenia

Symptoms include mucosal bleeding and prolonged bleeding times. The type of spontaneous bleeding that occurs with GT includes excessive gingival (gum) bleeding during tooth eruption, nose bleeds, and superficial skin bleeds. Dogs under 18 months in age are most susceptible to spontaneous bleeding.

Diagnosing Glanzmann's Thrombasthenia

DNA tests are used to confirm diagnosis.

Treating Glanzmann's Thrombasthenia

Young animals with chronic mucosal bleeding are at risk for iron deficiency anemia and should be monitored monthly for iron status. Oral iron supplementation is not enough to maintain normal levels of iron so iron injections are recommended. For unknown reasons, spontaneous bleeding usually subsides when dogs become young adults even thought the underlying cause is never cured.

Care for Dogs with Glanzmann's Thrombasthenia

Owners of dogs with GT should learn how to monitor the mucosal membranes and be sure to have their veterinarians perform tests every 6 months for hematocrit and serum iron levels. Adult dogs that continue to suffer from chronic anemia may need oral iron supplementation.

Help Future Generations of Dogs

Participate in canine health research by providing samples or by enrolling in a clinical trial. Samples are needed from healthy dogs and dogs affected by specific diseases.