Join Dr Katja Gorts as she discusses this fascinating therapy and its relevance to veterinary indications. Hirudotherapy, the application of medicinal leeches, is an ancient healing method that has been used since 100 - 600 BC. Before substances like heparin and coumarin derivates were developed leech therapy was widely used to treat and prevent thromboembolism. Today hirudotherapy gains more and more relevance in the treatment of lymphatic and venous insufficiencies, dentistry and pain control, e.g. in active osteoarthritis. It is approved by the Food and Drug Administration (FDA) for the treatment of impaired wound healing due to venous congestion in humans. The saliva of medicinal leeches contains at least 30 single substances that are not fully described and identified regarding their structure and pharmacological effects. The therapeutic effect is based predominantly on a combination of blood thinning, antithrombotic, analgesic, antiphlogistic, and local anesthetic effects. Indications for leech therapy in veterinary medicine include laminitis, navicular disease, tendon and ligament injuries, impaired wound healing, lymphangitis, hematoma, osteoarthritis, elbow and hip dysplasia. Application of leeches on specific acupuncture points or using them in conjunction with acupuncture according to the animal's specific TCVM diagnosis may provide enhanced and prolonged therapeutic effects.