Coagulation Factor Deficiency in Dogs
Coagulation takes place when blood transforms from a free flowing liquid into a thickened gel like state. In this state the gelled blood is called a clot, and it is through clotting that a wound begins to seal. This process is critically important for healing to take place. When your dog is injured and continues to bleed uncontrollably, this may be symptomatic of a defect in one or more of the processes that bring about coagulation. A complex series of enzyme reactions are involved in turning blood from a fluid to a gel. A failure in one of these processes can cause prolonged hemorrhaging after an injury, and will result ultimately in blood loss anemia. The failure of blood to coagulate can also result in internal hemorrhaging. Knowing the symptoms to watch for is crucial.
The condition or disease described in this medical article can affect both dogs and cats. If you would like to learn more about how this disease affects cats, please visit this page in the PetMD health library.
Symptoms and Types
Symptoms of coagulation factor deficiency can include prolonged bleeding after surgery or trauma, an obvious external symptom. Some of the less obvious symptoms that can be indicative of a coagulation deficiency are related to blood loss anemia and internal bleeding. With blood loss anemia, symptoms can present as weakness, lethargy, short breath, irregular heart beat, confusion, and a condition known medically as pica -- a compulsive behavior that is often intended to balance a lack of minerals or vitamins in the blood, in this case, iron deficiency from loss of blood. Internal bleeding may present as bloody vomit or stools, bleeding from the rectum or vagina, difficulty breathing, abnormal heart rhythm, swollen or hard abdomen, and excessive thirst.
Causes
Several factors can determine the probability that your pet is suffering from coagulation factor deficiency. An underlying disorder, such as vitamin K deficiency, can affect the functioning of the liver, one of the primary sites for synthesizing the enzymes necessary for coagulation. Other problems with the liver can also affect the process of enzyme synthesization. The underlying cause for coagulation deficiency can also be predisposed by hereditary traits. An example of this is Hemophilia. Both the A and B forms of hemophilia are x-linked recessive traits, where males bleed excessively and the females carry the trait and pass it on. Hemophilia is characterized by an abnormally low amount of the protein needed to bind blood platelets into a clot. This protein process is one of the coagulation factors that the body utilizes for clotting external and internal wounds. Hemophilia can be mild, moderate, or severe, and is not always inherited. It can also develop when the body forms antibodies that block the coagulation factor processes. Severe deficiency of coagulating factors will usually become apparent by four to six months of age. Milder deficiency may show up after an injury or after surgery.
In addition, external environmental circumstances may play a role in the incidence of coagulation factor deficiency. Ingestion of rat poison, or a snake bite, can affect the body's ability to process enzymes and proteins normally. Medically prescribed medications can affect the blood's ability to clot as well. Long term use of antibiotics can cause complications, and the use of prescription Heparin as an anti-coagulant (used for breaking up blood clots in the veins) can result in an accidental overdose.
Diagnosis
Your veterinarian may first want to rule out external factors, such as access to rodent poison, or recent contact with a snake or a lizard. A complete blood test will be ordered, and an assay of the blood's ability to coagulate will be used to determine the source of the disorder. If your dog shows signs of increased red blood cells (RBC), an indication of regenerative anemia, it will signal the possibility of internal blood loss.
Treatment
If blood loss is severe, your dog will be hospitalized and will receive blood and plasma transfusions. In fact, repeated transfusions may be necessary to control or prevent further hemorrhaging. Your veterinarian will probably also prescribe vitamin K, especially if your dog has ingested rodent poison or is experiencing other conditions that deplete this vitamin.
Living and Management
The blood will continue to be tested on an ongoing basis to determine the effectiveness of vitamin K supplementation. It should begin to normalize 24 to 48 hours after the beginning of therapy. The only way to test whether a hereditary deficiency has been treated successfully is by factor analysis; whether the hematomas (collections of clotted blood) have been resolved, and most importantly, whether the bleeding has stopped. Transfusion sometimes causes immune reactions when antibodies resist the new blood. If transfusion is a decided treatment, your pet will need to be monitored for symptoms of rejection.
There is no particular breed that is more susceptible than another, so there is nothing that can be done to prevent it unless it is known to be in the genetic makeup of a breeding dog. If it is determined that a hereditary factor is responsible for the coagulation factor deficiency, it is best not to breed this dog.