Metabolic changes associated with anaesthesia and cherry poisoning in a pony

Observations  A case of a pony with severe cyanide intoxication as a result of cherry ingestion is presented. General anaesthesia was performed for colic surgery. Severe metabolic lactate acidosis in combination with a high arterial oxygen partial pressure and clinically good peripheral perfusion parameters were the remarkable signs during anaesthesia. Severe hypothermia was obvious during recovery. Ten hours post-surgery the pony was euthanized as a result of neurological signs. The diagnosis of cyanide intoxication was made post-mortem.
Conclusion  Cherry ingestion can lead to lethal cyanide intoxication in horses indicated by severe nonhypoxic lactic acidosis during anaesthesia.     

Propofol anaesthesia for surgery in late gestation pony mares

Objective To characterize propofol anaesthesia in pregnant ponies. Animals Fourteen pony mares, at 256 ± 49 days gestation, undergoing abdominal surgery to implant fetal and maternal vascular catheters. Materials and methods Pre‐anaesthetic medication with intravenous (IV) acepromazine (20 µg kg^?1), butorphanol (20 µg kg^?1) and detomidine (10 µg kg^?1) was given 30 minutes before induction of anaesthesia with detomidine (10 µg kg^?1) and ketamine (2 mg kg^?1) IV Maternal arterial blood pressure was recorded (facial artery) throughout anaesthesia. Arterial blood gas values and plasma concentrations of glucose, lactate, cortisol and propofol were measured at 20‐minute intervals. Anaesthesia was maintained with propofol infused initially at 200 µg kg^?1 minute^?1, and at 130–180 µg kg^?1 minute^?1 after 60 minutes, ventilation was controlled with oxygen and nitrous oxide to maintain PaCO₂ between 5.0 and 6.0 kPa (37.6 and 45.1 mm Hg) and PaO₂ between 13.3 and 20.0 kPa (100 and 150.4 mm Hg). During anaesthesia flunixin (1 mg kg^?1), procaine penicillin (6 IU) and butorphanol 80 µg kg^?1 were given. Lactated Ringer's solution was infused at 10 mL kg^?1 hour^?1. Simultaneous fetal and maternal blood samples were withdrawn at 85–95 minutes. Recovery from anaesthesia was assisted. Results Arterial blood gas values remained within intended limits. Plasma propofol levels stabilized after 20 minutes (range 3.5–9.1 µg kg^?1); disposition estimates were clearance 6.13 ± 1.51 L minute^?1 (mean ± SD) and volume of distribution 117.1 ± 38.9 L (mean ± SD). Plasma cortisol increased from 193 ± 43 nmol L^?1 before anaesthesia to 421 ± 96 nmol L^?1 60 minutes after anaesthesia. Surgical conditions were excellent. Fetal umbilical venous pH, PO₂ and PCO₂ were 7.35 ± 0.04, 6.5 ± 0.5 kPa (49 ± 4 mm Hg) and 6.9 ± 0.5 kPa (52 ± 4 mm Hg); fetal arterial pH, PO₂ and PCO₂ were 7.29 ± 0.06, 3.3 ± 0.8 kPa (25 ± 6 mm Hg) and 8.7 ± 0.9 kPa (65 ± 7 mm Hg), respectively. Recovery to standing occurred at 46 ± 17 minutes, and was generally smooth. Ponies regained normal behaviour patterns immediately. Conclusions and clinical relevance Propofol anaesthesia was smooth with satisfactory cardiovascular function in both mare and fetus; we believe this to be a suitable anaesthetic technique for pregnant ponies.     

Surgical treatment of synovial osteochondromatosis in the middle carpal joint of a pony

A 9‐year‐old Paint pony gelding presented for signs of left carpal swelling of 1–2 weeks' duration. Radiographic, ultrasonographic and arthroscopic evaluation of the left carpus was consistent with synovial osteochondromatosis. This presumptive clinical diagnosis was confirmed histopathologically. Arthroscopic removal of the osteochondral bodies resulted in resolution of the carpal effusion and return to previous athletic activity by 4.5 months post operatively. Arthroscopic removal of osteochondral bodies is the treatment of choice in cases of suspected synovial osteochondromatosis.     

Closed reduction of scapulohumeral joint luxation in an Icelandic horse after general anaesthesia

This report describes the clinical, ultrasonographic and radiographic findings in an 8‐year‐old Icelandic mare with unilateral shoulder luxation after general anaesthesia. Reduction of the luxated humerus was performed in a closed fashion using a calving jack under general anaesthesia. The horse recovered well and ultimately returned to its previous level of performance.     

Acute normovolaemic haemodilution in a Clydesdale gelding prior to partial resection of the left ventral concha under general anaesthesia

A 16‐year‐old Clydesdale gelding underwent oral extraction of tooth 210 under standing sedation with partial resection of the left ventral concha under general anaesthesia 4 days later. Due to the highly vascular nature of the surgical site, significant intraoperative haemorrhage was anticipated. A lack of compatible donor horses confirmed by crossmatching prompted an autologous donation of 6 l of blood and acute normovolaemic haemodilution using a gelatine solution immediately prior to surgery. Intraoperative haemorrhage was estimated at 5% circulating volume and autologous transfusion was commenced once haemostasis was confirmed. The horse recovered uneventfully from general anaesthesia and surgery. To our knowledge this is the first report of acute normovolaemic haemodilution used in a clinical equine case.     

Ruptured capsule of the elbow joint of a draught horse

A cyst filled with fluid was found to be the cause of an enlarged antebrachium in a horse. Communication between the cyst and the elbow joint was demonstrated by: 1) finding, during radiographic examination of the elbow, radiopaque contrast solution instilled into elbow joint within the cyst; 2) finding cytological values in fluid aspirated from the cyst that were similar to those in fluid aspirated from the elbow joint; and 3) finding hyperechoic foci, assumed to be air bubbles, during ultrasonographic examination of the cyst after administration of air into the elbow joint. Communication of the cyst with the elbow joint was confirmed during post mortem examination of the affected limb.     

Osteochondrosis of the elbow joint in young dogs

Osteochondrosis is a failure of the normal process of endochondral ossification. In the elbow joint there are three manifestations of osteochondrosis, namely osteochondritis dissecans of the medial condyle of the humerus, ununited coronoid process and ununited anconeal process. This paper describes a series of sixty-eight cases diagnosed at a referral centre over a 10-year period. Ununited coronoid process and OCD of the medial condyle are not readily diagnosed because the lesions are difficult to demonstrate radiographically, but signs of degenerative joint disease of the elbow in young dogs of the medium to large breeds is strongly suggestive. Surgical treatment is indicated and the surgical approach to the medial aspect of the joint is described.     

Tracheal rupture following general anaesthesia in a horse

A Dutch Warmblood, with no other underlying clinical disease, presented for surgical excision of a sarcoid tumour on the distal right pinna under general anaesthesia. At the end of the procedure, immediately before being moved to recovery, the horse became light and made repeated attempts to move whilst attached to the hoist. Anaesthesia was deepened with intravenous thiopental sodium (Thiopentone)¹ and the horse was moved into the recovery room. The trachea was extubated with the cuff of the endotracheal tube inadvertently left partially inflated. Recovery was smooth and the horse stood uneventfully. The following day subcutaneous emphysema was noted along the neck and tracheoscopy revealed an abnormal dorsoventrally flattened trachea and a 5 cm tear in the dorsal aspect of the trachea. Symptomatic treatment resulted in progressive healing of the lesion and the horse recovered fully with no evidence of respiratory complications.     

Avian anaesthesia in general practice

This paper reviews the management of General Anaesthesia in 32 birds. The methods adopted are outlined with particular reference to the drug CT 1341*, which was used for induction and, on some occasions, maintenance of anaesthesia.     

Equine perioperative fatalities associated with general anaesthesia at a private practice--a retrospective case series

OBJECTIVE: To determine the fatality rate of horses undergoing general anaesthesia at a private equine referral practice using a limited number of anaesthetic protocols. METHODS: A retrospective analysis of records (n = 17 961) from all horses undergoing general anaesthesia for surgical procedures from 1997 to 2001 at Rood and Riddle Equine Hospital, Lexington, Kentucky, USA. Results were reported as percentage of the population, and as crude mortality rates for each procedure (deaths per 1000). RESULTS: The prevalence of equine fatalities directly related to anaesthesia was 0.12% (n = 21) and this rose to 0.24% (n = 42) with the inclusion of horses killed or dying within 7 days post general anaesthesia. Causes of death directly related to anaesthesia were cardiac arrest (n = 10), fracture in recovery stall (n = 8), neuropathy and myopathy necessitating euthanasia (n = 3). Crude mortality rates per procedure were < or =7 deaths per 1000 cases, except arthrodesis/osteotomy cases were 66.7 deaths per 1000 cases. CONCLUSIONS: The anaesthetic fatality rate at this practice is lower than has been reported previously. CLINICAL RELEVANCE: Familiarity with an anaesthetic protocol in combination with reduced anaesthetic time, emergencies of shorter duration between diagnosis and surgery, and adequate preoperative examination appear to minimize the risks associated with general anaesthesia in horses.