Bleeding, Severe
Severe bleeding in pets constitutes an acute emergency that requires immediate action. Severe bleeding is defined as a significant blood loss caused by injury to blood vessels, which, if left untreated, can lead to life-threatening conditions. Depending on the type of vessel affected, we distinguish three main types of bleeding: Arterial bleeding is characterized by bright red, pulsating blood and is particularly dangerous as arterial blood is under high pressure. Venous bleeding is characterized by dark red, steadily flowing blood. Capillary bleeding is more superficial and less dramatic, with blood seeping from small vessels in the skin.
In pets, blood losses of more than 15-20% of total blood volume can lead to hypovolemic shock. Especially small dog breeds and cats have a lower blood volume and can therefore develop critical conditions more quickly. The total blood volume of an animal is about 80-90 ml per kilogram of body weight, which means that a 5 kg cat has only about 400-450 ml of blood. A loss of just 80 ml can therefore already be critical.
Causes
Severe bleeding in pets can be caused by various factors. Traumatic injuries are the most common cause, including traffic accidents, falls from great heights, bite wounds from other animals, or cuts from sharp objects. For cats, falls from high-rise buildings and territorial fights are frequent triggers, while for dogs, traffic accidents and injuries during play or from foreign objects predominate.
In addition to external trauma, internal bleeding can also occur, such as from splenic ruptures, liver trauma, or tumor bleeding. These are particularly insidious as they are not immediately visible externally. Coagulation disorders form another important group of causes. These include congenital diseases such as von Willebrand’s disease in certain dog breeds (especially Dobermans) or acquired disorders due to poisoning (e.g., rat poison/coumarin derivatives), liver diseases, or medications such as non-steroidal anti-inflammatory drugs.
Iatrogenic causes such as complications after surgical procedures or blood draws can also lead to severe bleeding, especially in animals with pre-existing coagulation disorders.
Symptoms
The symptoms of severe bleeding vary depending on the location, extent, and speed of blood loss. In external bleeding, the blood loss is visibly apparent. Arterial bleeding is recognizable by bright red, pulsating blood, while venous bleeding is characterized by dark red, steadily flowing blood. In internal bleeding, however, the signs are more subtle and can be easily overlooked.
Systemic symptoms of major blood loss include pale to white mucous membranes, prolonged capillary refill time (over 2 seconds), tachycardia (increased heart rate), tachypnea (rapid breathing), weakness, lethargy, and in advanced cases, altered consciousness leading to collapse. In cases of bleeding into the abdominal cavity, the abdomen may appear distended and painful upon palpation. Thoracic bleeding can lead to respiratory distress and cyanotic (bluish) mucous membranes.
Especially in cats, the signs of shock can be very subtle, as these animals often conceal symptoms of stress and pain. A quiet, withdrawn cat with pale mucous membranes should therefore always be cause for concern.
First Aid
- Remove any foreign objects that may have entered the wound.
- However, do not examine the wound and do not attempt to clean a heavily bleeding wound yourself.
- Focus only on stopping the bleeding.
- Apply a bandage or a clean cloth to the wound and maintain steady pressure on the wound until it stops bleeding. For arterial bleeding, this may take up to 15 minutes.
- If necessary, apply a thick bandage that maintains consistent pressure.
- For head injuries, be careful not to apply pressure to the eyes.
- Also, do not apply pressure if you suspect a foreign object is still in the tissue.
- Take your pet to a quiet place, wrap it in a blanket, and place it on the floor if possible so it can’t fall if it becomes restless.
- If blood soaks through your bandage, don’t remove it; instead, add more bandaging material on top.
- If the heavily bleeding wound is on a leg, you can also try to reduce overall blood flow by applying a tourniquet. However, do not leave it on for more than 20 minutes.
Diagnosis
The diagnosis of severe bleeding begins with a thorough clinical examination. With external bleeding, the diagnosis is obvious, but the extent of the injury and blood loss must be assessed. For internal bleeding, imaging procedures are essential. Ultrasound examination (sonography) is particularly valuable as it is non-invasive and can quickly detect free fluid in body cavities. For abdominal bleeding, an abdominocentesis can be performed to confirm that the free fluid is blood.
X-rays can provide evidence of organ injuries, foreign bodies, or fractures that may be associated with bleeding. In specialized facilities, computed tomography (CT) or magnetic resonance imaging (MRI) can provide more detailed information about the source of bleeding.
Laboratory tests are necessary to quantify the extent of blood loss and identify coagulation disorders. A blood count provides information on hematocrit, erythrocyte count, and hemoglobin value. These values may initially still be normal in acute bleeding, as the body has not yet responded with fluid shifts. Coagulation tests such as prothrombin time (PT), activated partial thromboplastin time (aPTT), and platelet count help identify coagulation disorders.
Further veterinary measures
Take your pet to a veterinarian as quickly as possible.
Major arterial bleeding carries the risk of significant blood loss and can be difficult for a layperson to stop. There is a danger of hypovolemic shock or bleeding to death.
The treatment of severe bleeding follows the principle of “hemostasis and circulatory stabilization”. For external bleeding, direct compression is the most important first measure. A pressure bandage should be applied; for arterial bleeding, a tourniquet (ligature) proximal to the source of bleeding may be necessary for a maximum of 20 minutes. In penetrating injuries, foreign objects should not be removed as they may be tamponading vessels.
Circulatory stabilization is achieved through intravenous fluid therapy, preferably with crystalloid solutions such as Ringer’s lactate or isotonic saline. In cases of severe blood loss, colloids or blood transfusions may be necessary. Ideally, blood typing should be performed before a transfusion, especially in cats, which can develop severe transfusion reactions.
Definitive surgical care includes identification and ligation of bleeding vessels, removal of damaged tissue, and wound closure. For internal bleeding, exploratory laparotomy or thoracotomy may be necessary. In some cases, interventional procedures such as embolization of bleeding vessels using angiography can be an alternative to open surgery.
In cases of coagulation disorders, treating the underlying cause is crucial. For poisoning with anticoagulants such as warfarin, vitamin K1 is administered, supplemented by plasma or whole blood transfusions in severe cases.
Prognosis and aftercare
The prognosis for severe bleeding depends significantly on the cause, extent of blood loss, time until treatment, and the presence of additional injuries or underlying conditions. Externally treated bleeding generally has a good prognosis, while massive internal bleeding or bleeding due to severe coagulation disorders may be associated with higher mortality.
Follow-up care includes regular monitoring of vital parameters, hematocrit, and wound healing. In cases of significant blood loss, anemia may persist, requiring supportive therapy with iron supplements. The regeneration of red blood cells usually takes 3-4 weeks. During this time, the animal should be rested and only engage in light physical activity.
For surgically treated wounds, attention should be paid to signs of infection or renewed bleeding. Drains must be regularly checked and removed at the right time. Depending on the underlying condition, further specific follow-up measures may be necessary. These include long-term anticoagulant therapy for thrombosis or chemotherapy for tumor bleeding.
Summary
Severe bleeding in pets constitutes a medical emergency that requires immediate action. It can be triggered by various causes such as trauma, coagulation disorders, or tumor diseases. Recognition is based on clinical symptoms such as visible blood loss, pale mucous membranes, and circulatory instability. For internal bleeding, imaging procedures and laboratory tests are crucial for diagnosis.
The therapy follows the principle of rapid hemostasis and circulatory stabilization, followed by definitive surgical care. The prognosis depends on the extent of blood loss, the underlying cause, and the speed of treatment. Careful follow-up care is essential to avoid complications and ensure complete recovery.
Pet owners should know basic first aid measures for bleeding and act quickly in an emergency. A well-equipped first aid kit for pets should be available in every household and regularly checked for completeness.
Outlook on current research
Research in the field of hemostasis and bleeding management in pets is continuously evolving. New hemostatic materials such as zeolite-based powders or chitosan bandages show promising results in rapid hemostasis and are increasingly used in veterinary medicine. These materials promote blood clotting through various mechanisms such as water withdrawal or direct activation of the coagulation cascade.
In the field of transfusion medicine, blood substitutes and artificial oxygen carriers are being researched, which could potentially reduce the need for blood transfusions. These products would have the advantage of longer shelf life and universal applicability without blood group compatibility.
Minimally invasive surgery and interventional radiology are also gaining importance in veterinary medicine. Techniques such as endovascular embolization allow targeted closure of bleeding vessels without open surgery, which can be particularly advantageous for internal bleeding.
In the field of coagulation disorders, new diagnostic tests are being developed that provide faster and more precise results. Point-of-care devices for measuring coagulation parameters enable timely diagnosis and therapy adjustment directly in the practice.
Frequently asked questions (FAQs)
- How Do I Recognize if My Pet Has Internal Bleeding?
Look for symptoms such as pale mucous membranes, weakness, rapid breathing, accelerated heartbeat, distended abdomen, or collapse. If you suspect internal bleeding, you should immediately consult a veterinarian. - Can I Help My Pet Myself in Case of Severe Bleeding?
Yes, by applying direct pressure to the wound with a clean cloth or bandage. Elevate the affected limb and transport the animal calmly to the veterinarian. Do not remove foreign objects from wounds. - How Long Does It Take for My Pet to Recover After Severe Blood Loss?
Recovery can take 3-4 weeks depending on the severity. The formation of new red blood cells takes time, during which the animal should be rested. - Do Cats and Dogs Require Different Treatments for Bleeding?
The basic principles are the same, but cats have specific blood types and can develop severe transfusion reactions. They also react more sensitively to certain medications. - Which Dog Breeds Are Particularly Susceptible to Clotting Disorders?
Dobermans, German Shepherds, Poodles, and Scottish Terriers have an increased risk for von Willebrand’s disease. Hemophilia is more common in German Shepherds and Boxers. - How Can I Prevent Bleeding in My Pet?
Keep your pet on a leash in high-traffic areas, secure your garden, avoid sharp objects in the household, and ensure regular veterinary check-ups. - What Should a Pet First Aid Kit Contain?
Sterile compresses, elastic bandages, adhesive tape, scissors, tweezers, disposable gloves, disinfectant, and ideally hemostatic dressings or powder. - Can My Pet Bleed to Death from a Small Cut?
This is unlikely in healthy animals. However, in animals with clotting disorders or if arteries are injured, even smaller wounds can lead to dangerous bleeding.
Literature
- Löwe, G. and Löwe, O., 2021. Emergencies in Dogs and Cats – A Veterinary Guide. Kreuztal: Kynos-Verlag.
- Holowaychuk MK, Hanel RM. Canine and Feline Emergency and Critical Care. 2nd ed. Hoboken: Wiley-Blackwell; 2021.
- Plunkett SJ. Emergency Procedures for the Small Animal Veterinarian. 3rd ed. London: Elsevier; 2019.
- Giger U. Transfusion Medicine and Blood Banking in Small Animals. Veterinary Clinics of North America: Small Animal Practice. 2021;51(1):1-19.
- Kelmer E, Segev G, Papashvilli V, et al. Effects of Intravenous Administration of Tranexamic Acid on Hematological, Hemostatic, and Thromboelastographic Analytes in Healthy Adult Dogs. Journal of Veterinary Emergency and Critical Care. 2020;30(1):60-66.
- Lynch AM, Respess M, Boll AE, et al. Hospital-Acquired Coagulopathy in Critically Ill Dogs and Cats: A Retrospective Study. Journal of Veterinary Emergency and Critical Care. 2019;29(6):653-660