It is widely stated within the veterinary literature that manipulation of a mast cell tumour can lead to an anaphylactoid reaction; however, there is limited information on the frequency or management of such cases in companion animals. A nine-year-old, 38.4 kg, female neutered, labrador (retriever) presented for excision of a cutaneous mast cell tumour located on the left lower eyelid. This report describes a Grade III anaphylactoid crisis (hypotension, bradycardia and bronchospasm) that occurred when the dog was under general anaesthesia following mast cell degranulation. Prompt management following fluid resuscitation, administration of an aerosolised bronchodilator and intravenous atropine, successfully addressed the underlying pathophysiology of anaphylactoid crisis. BACKGROUND

Summary Background Ketamine at 2.2 mg/kg given i.v. is often used to induce anaesthesia for surgical procedures in horses under field conditions. Commonly, additional doses are needed to complete the surgery. We hypothesised that surgical conditions would be improved when 5 mg/kg of ketamine was used to induce anaesthesia, while induction and recovery qualities would not differ from those when 2.2 mg/kg ketamine was used. Objective To compare the anaesthetic effects of two ketamine doses (5 and 2.2 mg/kg) during field anaesthesia for castration of horses. Study design Prospective, randomised, blinded, clinical study. Method Seventy‐seven client‐owned Icelandic horses presented for castration under field conditions were studied. Pre‐anaesthetic medication was xylazine (0.7 mg/kg) butorphanol (25 μg/kg) and acepromazine (50 μg/kg) injected i.v. Anaesthesia was induced with either 2.2 mg/kg (K2.2) or 5 mg/kg (K5) i.v. of ketamine mixed with diazepam (30 μg/kg). The quality of induction, surgical conditions and recovery were compared using subjective and objective measures, and the number of additional ketamine doses recorded. Results Ketamine 5 mg/kg provided better surgical conditions and a more rapid induction. Recovery quality was subjectively better in K2.2. Five horses in K2.2 and two in K5 required additional ketamine doses. Main limitations While the pre‐anaesthetic sedation and benzodiazepine doses were consistent among horses, the level of sedation and muscle relaxation achieved differed. Conclusion A ketamine dose of 5 mg/kg can be used to improve the quality of field anaesthesia for castration in Icelandic horses. Although recovery quality is subjectively better when using 2.2 mg/kg, no adverse events were observed during recovery with either dose The Summary is available in Portuguese – see

Two cases of suspected anaphylaxis occurred in the authors’ hospital within two weeks of each other. The first, a six-year-and-four-month-old border collie, presented for thoracic wall resection. Once anaesthetised, 20 mg/kg of intravenous cefuroxime (Zinacef 75 mg/ml, GlaxoSmithKline UK) was administered slowly for prophylactic antibiosis. Ten minutes after administration was completed,desaturation occurred alongside tachycardia, hypotension and apnoea. Chest compliance was extremely poor, with minimal chest movement. Treatment included intermittent positive pressure ventilation, intravenous fluids, terbutaline, adrenaline and dexamethasone. The second case, a five-year-and-eight-month-old Lhasa apso, presented for elective orthopaedic surgery. Intravenous cefuroxime (Zinacef 75 mg/ml) was again administered slowly for prophylactic antibiosis; however, it is uncertain whether the patient received the full dose of 20 mg/kg. Mid-administration tachycardia, tachypnoea and hypotension occurred,alongside poor chest compliance. Cefuroxime administration was stopped, the fluid line disconnected and treatment with chlorphenamine given.

Anaesthetic management can be challenging when patients have multiple comorbidities. This report presents one such case: a pug with brachycephalic airway syndrome, in late gestation, presented with a lung lobe torsion. Under general anaesthesia the dog initially had low PaO2, with severe ventilation perfusion mismatch and pulmonary shunt; this was mildly improved with the patient positioned on a head-up tilted table in right lateral recumbency. Tension pneumothorax developed after initiation of positive pressure ventilation and was resolved with rapid entry into the thoracic cavity. Ventilation was adjusted with the aid of spirometry, blood gases, capnography and direct visualisation of the lung tissue. The dog made a full recovery and was discharged from hospital five days postoperatively.