Anaesthesia
Isoflurane
Because of the relative high price (2-3 times of Halothane) this halogenated ether is rarely used in veterinary practice. The low coefficient of solubility (Isoflurane 1,4; Halothane 2,3) renders induction of anaesthesia and recovery very fast. Also the low metabolic rate (Isoflurane 0,3%; Halothane 20%) offers a lower burden to the liver compared to other inhalation anaesthetics. Till today cases of liver damage after the use of Isoflurane have not been reported. Although endotracheal intubation is sometimes recommended, anaesthesia application via a mask is more convenient. A concentration as high as 5 per cent with 0,5-0,8 litre per minute of oxygen is used for induction of anaesthesia. This concentration seems to be safe in very sick animals too. Usually the concentration is reduced to 1,5 to 3 per cent as soon as a noticeable relaxation is registered. This concentration may vary considerably in some species or even between animals of the same species. Because of this and the fast response to all changes in the anaesthetic concentration it is necessary to have a person monitoring only the anesthetic flow to maintain the patient at the lowest possible concentration. The patient usually recovers very fast (5-10 minutes).
Surgery
Orthopaedic techniques
Bone injuries in the avian patient tend to heal in a reasonable manner and are amenable to a variety of fixation methods. In contrast, maintenance of soft tissue and joint mobility, the most vital components of return to full function in birds, may be hindered by many techniques used for immobilization of fractures and luxations. The Doyle techniques are the simplest, fastest and in many cases, the only way to achieve union in injuries such as fractured jaws. Various methods of applying splints have been successfully used for years in small bird leg fractures, primarily tibiotarsus. External fixators are generally considered the best stabilisation technique for immobilizing fractures in birds that require a full return to function.
Soft Tissue surgery
Automutilation in the region of the christa sternalis in psittacines
Deep ulcerative automutilation in the region of the christa sternalis is not uncommon in clinical avian practice, although it is seldom published. The described surgical procedure is an useful method to treat this condition in psittacines. Although the primary cause of this syndrome is not known this aggressive treatment is successful. Conservative treatments used in the past did not bring satisfactory results. Only few birds with mild inflammation of muscle and bone recovered using a collar and Iodine lotion with Cromoglicinacid-Disodium (BetaisodonaR + IntalR) without surgical removement of a part of the christa sternalis or muscle. Debridement of necrotic skin with or without suturing of the skin was not successful. Flying ability was not reduced so the birds could be removed in the aviary after 6-7 weeks after surgery.
Surgical Treatment of Impacting Uropygial Glands in Birds Affected by Pruritus and Feather Picking
Impaction of the uropygial gland plays an important role in the development of feather picking and skin disorders. Individuals from every bird species that possesses this gland should be carefully examined when presented with these clinical signs. The high incidence of these signs in African Grey Parrots makes this syndrome potentially very important in this species. Total excision of the gland should be avoided in all cases and has not been necessary in the authors´ experience. The goal of the treatment is to achieve the physiological function of the gland, because it plays an important role in normal skin homeostasis. A dietary deficiency, mainly hypovitaminosis A, is postulated to be the primary cause, because all birds seen with impaction of the gland have been fed a poor diet consisting predominately of sun flower seeds.
Surgery of the reproductive system
Egg-retention in cockatiels and egg-related peritonitis are common clinical findings in a companion avian practice and are the primary causes relating to surgery of the reproductive tract. Diagnosis can be made from a combination of the clinical presentation and cytology of the abdominal aspiration sample. Initial medical therapy includes dexamethasone, depomedroxyprogesterone acetate and testosterone. The retained egg is then removed and a salpingohysterectomy performed. We prefer the left lateral celiotomy.