Veterinary surgery is surgery performed on animals by veterinarians, whereby the procedures fall into three broad categories: orthopaedics (bones, joints, muscles), soft tissue surgery (skin, body cavities, cardiovascular system, GI/urogenital/respiratory tracts), and neurosurgery. Advanced surgical procedures such as joint replacement (total hip, knee and elbow replacement), fracture repair, stabilization of cranial cruciate ligament deficiency, oncologic (cancer) surgery, herniated disc treatment, complicated gastrointestinal or urogenital procedures, kidney transplant, skin grafts, complicated wound management, and minimally invasive procedures (arthroscopy, laparoscopy, thoracoscopy) are performed by veterinary surgeons (as registered in their jurisdiction). Most general practice veterinarians perform routine surgeries such as neuters and minor mass excisions; some also perform additional procedures. The goal of veterinary surgery may be quite different in pets and in farm animals. In the former, the situation is more close to that with human beings, where the benefit to the patient is the important factor. In the latter, the economic benefit is more important. Specialization in surgery In the United States, Canada and Europe, veterinary surgery is one of 22 veterinary specialties recognized by the American Veterinary Medical Association respectively the European Board of Veterinary Specialisation. Those wishing to become board certified must undergo a one-year clinical internship program followed by three years of intensive training in a residency program under direct supervision of board certified veterinary surgeons, including performance of a large number of surgical procedures in such categories as abdominal surgery, surgical treatment of angular limb deformities, arthroscopic surgery, surgery of the foot, fracture fixation, ophthalmic surgery, urogenital surgery, and upper respiratory surgery, etc. Once the minimum requirements of training are met, residents are required to pass a rigorous certification examination before being admitted as members (diplomates) of the American College of Veterinary Surgeons or European College of Veterinary Surgeons. Veterinary anesthesia Anesthesia in animals has many similarities to human anesthesia, but some differences as well. Local anesthesia is primarily used for wound closure and removal of small tumors. Lidocaine, mepivacaine, and bupivacaine are the most commonly used local anesthetics used in veterinary medicine. Sedation without general anesthesia is used for more involved procedures. Sedatives commonly used include acepromazine, hydromorphone, midazolam, diazepam, xylazine, and medetomidine. α2 agonists like xylazine and medetomidine are especially useful because they can be reversed, xylazine by yohimbine and medetomidine by atipamezole. Xylazine is approved for use in dogs, cats, horses, deer, and elk in the United States, while medetomidine is only approved