Changes in clinical, hematologic and biochemical indicators in controlled respiration during anesthesia in dogs]

Some clinico-biochemical parameters were investigated in fifty clinically healthy dogs in the course of controlled breathing in halothane inhalation anaesthesia to evaluate in a complex manner the dynamics of metabolic processes in the dog organism. The test dogs were divided into three groups. In the first test group, ECG and values of acid-base balance parameters in venous blood were followed in ten dogs. In the second test group, the values of blood gases were followed in addition to the above-mentioned parameters in twenty anesthetized dogs. In the third test group comprising twenty animals, acid-base parameters in arterial blood and blood gas tension were evaluated. Greatest divergences were recorded in pH values, blood gas tension and acid-base balance values. Partly compensated respiration acidosis was observed already in 30 minutes from the start of anaesthesia, as shown by complex evaluation. The results indicate that also in optimum ventilation programme it is necessary to apply infusion solutions to the internal environment of organism which will secure metabolic rebalancing in the course of artificial pulmonary ventilation.     

THE USE OF CZECHOSLOVAK VENTILATOR ELVENT IN ARTIFICIAL VENTILATION DURING HALOTHANE NARCOSIS IN THE DOG

Czechoslovak ventilator ELVENT designed for artificial respiration in human was tested in dogs. SO experimental dogs were divided into 3 groups. The animals were under halothane anaesthesia and myorelaxation with artificial ventilation for 120–180 min. Before, during and after experiments at set intervals heart rate, temperature, ECG and acid-base balance (ABB) from venous and arterial blood values of blood-gases, concentrations of potassium and haemoglobin were determined. The model of ventilation program chosen in the third series appears to be the most acceptable for the clinical use. Ventilator parameters were set as follows: respiratory rate from 15 to 20 breaths per min, respiratory min volume from 1.5 to 3 litres, tidal volume from 0.15 to 03 litres. The duration of inspiration was from 0.8 to 1.2 sec., the duration of expiration was double this. Changes in ABB parameters and the tension of blood gases demonstrated the development of respiratory acidosis, in the majority of cases partly compensated.     

Clinical evaluation of a valveless non-absorber breathing system in spontaneously breathing canine patients

A valveless non-absorber breathing system novel to veterinary anaesthesia is described. The performance of this system was evaluated in 35 anaesthetised spontaneously breathing dogs weighing between 2.1 and 56 kg. Fresh gas flows were reduced incrementally until rebreathing (defined as an increase in end-inspired carbon dioxide tension above 0.2 per cent) started to occur, as measured by capnography. A significant relationship (P < 0.0001) between critical fresh gas flow and bodyweight was determined, and a mean critical fresh gas flow rate of 145 +/- 21 ml/kg/minute was derived for 15 dogs weighing 10 kg or less (mean 6.7 +/- 2.6 kg) and one of 98 +/- 16 ml/kg/minute for the remaining 20 dogs weighing 11 kg or greater (mean 30.2 +/- 13.9 kg). The fresh gas requirements for each group were found to differ significantly (P < 0.0001), although the correlation between critical fresh gas flow and bodyweight was not significant (P = 0.054) in the dogs weighing 10 kg or less. It is suggested that the system may prove an economical and useful addition to the breathing systems currently used in canine anaesthesia.     

Hepatic effects of halothane, isoflurane or sevoflurane anaesthesia in dogs

The effects of halothane, isoflurane and sevoflurane anaesthesia on hepatic function and hepatocellular damage were investigated in dogs, comparing the activity of hepatic enzymes and bilirubin concentration in serum. An experimental study was designed. Twenty-one clinically normal mongrel dogs were divided into three groups and accordingly anaesthetized with halothane (n = 7), isoflurane (n = 7) and sevoflurane (n = 7). The dogs were 1-4 years old, and weighed between 13.5 and 27 kg (18.4 +/- 3.9). Xylazine HCI (1-2 mg/kg) i.m. was used as pre-anaesthetic medication. Anaesthesia was induced with propofol 2 mg/kg i.v. The trachea was intubated and anaesthesia maintained with halothane, isoflurane or sevoflurane in oxygen at concentrations of 1.35, 2 and 3%, respectively. Intermittent positive pressure ventilation (tidal volume, 15 ml/kg; respiration rate, 12-14/min) was started immediately after intubation and the anaesthesia lasted for 60 min. Venous blood samples were collected before pre-medication, 24 and 48 h, and 7 and 14 days after anaesthesia. Serum level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT), lactate dehydrogenase (LDH GGT) activities and bilirubin concentration were measured. Serum AST, ALT and GGT activities increased after anaesthesia in all groups. In the halothane group, serum AST and ALT activities significantly increased all the time after anaesthesia compared with baseline activities. But in the isoflurane group AST and ALT activities increased only between 2 and 7 days, and in the sevoflurane group 7 days after anaesthesia. GGT activity was increased in the halothane group between 2 and 7 days, and in the isoflurane and sevoflurane groups 7 days after anaesthesia. All dogs recovered from anaesthesia without complications and none developed clinical signs of hepatic damage within 14 days. The results suggest that the use of halothane anaesthesia induces an elevation of serum activities of liver enzymes more frequently than isoflurane or sevoflurane from 2 to 14 days after anaesthesia in dogs. The effects of isoflurane or sevoflurane anaesthesia on the liver in dogs is safer than halothane anaesthesia in dogs.     

Xylazine premedication does not modify the onset and duration of cisatracurium blockade in anaesthetized dogs

The purpose of this study was to evaluate the effect of xylazine as premedication on the onset time and duration of cisatracurium neuromuscular blockade in anaesthetized dogs. This study was carried out on 12 healthy dogs aged 0.5-6 years and weighing 9-26 kg undergoing various elective surgical procedures. The dogs were randomly divided into two groups of t (test) and c (control), with six dogs each. In group t, premedication was conducted using acepromazine maleate 0.3 mg kg(-1) and xylazine 0.3 mg kg(-1) and in group c only acepromazine (same dose) was injected intramuscularly 20 min before general anaesthesia. After induction with thiopental, anaesthesia was maintained with halothane in oxygen to deliver an end-tidal halothane concentration of 1.1%. Neuromuscular blockade was induced with cisatracurium 0.2 mg kg(-1) and monitored using the train-of-four (TOF) stimulation pattern applied at the ulnar nerve. The onset time of cisatracurium blockade was 195 +/- 85.44 s in test and 153.3 +/- 38.16 s in control group. The duration of neuromuscular blockade was 24.8 +/- 4.79 min in t and 28.3 +/- 5.46 min in the c group. Statistical analysis of the data showed no significant difference between groups in terms of onset and duration of neuromuscular blockade.     

A clinical trial of propofol infusion anaesthesia in dogs

Studies were carried out on 40 dogs premedicated with acepromazine (0·05 mg. kg^-1) and atropine (0·02 mg. kg^-1) to determine the minimum infusion rate of propofol needed to maintain anaesthesia and to compare the quality of the anaesthesia with that produced by halothane/nitrous oxide/oxygen. In 30 dogs anaesthesia was induced with propofol and maintained with a continuous infusion and in the other ten dogs anaesthesia was induced with thiopentone and maintained with the inhalation agents. An infusion rate of 0·4 mg. kg^-1 min^-1 of propofol produced surgical anaesthesia in dogs breathing oxygen or oxygen-enriched air. Cardiovascular and respiratory effects were similar to those in dogs anaesthetized with halothane/nitrous oxide and with both anaesthetic regimens myocardial oxygen consumption appeared to increase with increasing duration of anaesthesia. A possible familial susceptibility resulting in a more prolonged recovery was revealed and propofol infusion was associated with a 16 per cent incidence of vomiting in the recovery period. It was concluded that in canine anaesthesia the continuous infusion of propofol to maintain anaesthesia in healthy dogs was safe but less satisfactory than the use of halothane/nitrous oxide.     

Cardiopulmonary effects of sufentanil long acting on sevoflurane anaesthesia in dogs

OBJECTIVE: To evaluate the cardiopulmonary effects of sufentanil long acting (SLA) in sevoflurane-anaesthetized dogs. STUDY DESIGN: Randomized prospective study. Animals Forty female dogs (beagles) aged 1-2 years, weighing 11.97 +/- 1.40 kg. MATERIALS AND METHODS: The dogs were divided into five groups of eight. Two control groups were used: group A received intramuscular (IM), SLA (50 microg kg(-1)) alone, while group B received the SLA vehicle followed by sevoflurane anaesthesia for 90 minutes. In the other groups, SLA (50 microg kg(-1) IM) was given immediately before (group C(0)), 15 minutes before (group D(15)) or 30 minutes (group E(30)) before induction [with intravenous (IV) thiopental] of sevoflurane anaesthesia lasting for 90 minutes. Heart rate, arterial blood pressure, respiratory rate (f(r)), arterial oxygen haemoglobin saturation and end-tidal sevoflurane concentration (Fe'SEVO) were measured every 10 minutes during anaesthesia and at 2, 4 and 24 hours after induction (not Fe'SEVO). Acid-base and blood gas analyses were performed. RESULTS: Sufentanil LA reduced heart rate and increased arterial CO(2) tensions during anaesthesia. Respiratory depression was least in group E(30) compared with groups C(0) and D(15). Bradycardia was present for at least 24 hours. Respiratory rate was least in group B although arterial O(2) and CO(2) tension values were acceptable up to 24 hours after anaesthesia. CONCLUSIONS: Pre-anaesthetic medication with SLA moderately aggravated the cardiopulmonary effects of sevoflurane. CLINICAL RELEVANCE: In spite of a moderate depressant effect on cardiorespiratory parameters, SLA may be of use as pre-anaesthetic medication before sevoflurane anaesthesia in dogs. Intermittent positive pressure ventilation may occasionally be necessary.     

The effects of halothane and nitrous oxide on the pharmacokinetics of propofol in dogs

The pharmacokinetics of propofol, 6.5 mg/kg, administered as a bolus dose intravenously (i.v.) were studied in six dogs (group 1). The effect of maintaining anaesthesia with halothane and nitrous oxide in oxygen on propofol pharmacokinetics was also investigated in six dogs undergoing routine anaesthesia (group 2). Induction of anaesthesia was rapid in all animals. Post-induction apnoea was a feature in three of the 12 dogs. The blood propofol concentration-time profile was best described by a bi-exponential decline in two dogs in group 1 and in 3 dogs in group 2, and by a tri-exponential decline in four dogs in group 1 and 3 dogs in group 2. The elimination half-life was long in both groups (90.9 min and 75.2 min, respectively), the volume of distribution at steady state large (4889 and 4863 ml/kg) and the clearance rapid (58.6 and 56.3 ml/kg.min). There were no significant differences between the groups, thus indicating that maintenance of anaesthesia with halothane and nitrous oxide had no effect on the pharmacokinetics of propofol in the dog.     

Effects of general anaesthesia on static respiratory compliance in dogs

The effect of anaesthesia on total, pulmonary and chest wall static respiratory compliance was investigated in healthy spontaneously breathing dogs undergoing orthopaedic surgery. Total compliance fell by 26 per cent from the baseline measurement within 25 minutes of the first measurement (P less than 0.01), while pulmonary and chest wall compliances fell by 34 per cent and 40 per cent, respectively (P less than 0.01). Pulmonary compliance ceased to fall after 50 minutes, but chest wall compliance was still declining after 70 minutes. The decline in compliance could be prevented by periodic full lung inflation, with a significant difference being found between inflated and uninflated dogs (P less than 0.01). The reduction in compliance during anaesthesia is believed to be a consequence of reduced functional residual capacity and the development of lung tissue atelectasis.     

Continuous intravenous anesthesia in dogs using a combination of xylazine, ketamine and guaifenesin]

The tested anaesthesia through a permanent infusion of a xylazine, ketamine and guaifenezine (XKG) mixture was used in ten experimental dogs without clinical signs of a disease and in fifty two patients during different surgical interventions. After joint i.m. atropine (0.05 mg/kg) and xylazine (2 mg/kg) premedication, anaesthesia in dogs was induced by an i.v. administration of 1% ketamine at a dose of 2 mg/kg, and the XKG was infused instantly after the previous treatment. The mixture contained 2.0 ml of 5% ketamine and 1.25 ml of 2% xylazine added to 100 ml of 5% guaifenezine. The infusion was applied at a rate of 3.3 ml/kg for the first five minutes and then it was maintained at constant values of 2.2 ml/kg during the whole surgical intervention (Tab. I). The induction and course of anaesthesia, and waking up and recovery from anaesthesia were evaluated in all dogs, and the trias values were also followed. These additional parameters were followed in the test group: breathing volumes, ECG values and acid-base balance parameters were determined from the collected blood samples. The observation of measurable parameters (Figs. 1 to 5) and ECG analysis did not demonstrate any large departures from the starting values, and the changes in the acid-base balance (Tab. II) suggest the partly compensated respiratory acidosis. On the basis of our results, we can recommend this tested method for general anaesthesia particularly of dogs of larger breeds and for longer-lasting operations. This method is suitable to be used first of all in the veterinary establishments where inhalation anaesthesia is not practicable.     

Evaluation of a non-rebreathing circuit for small animal anaesthesia

Several new multi-purpose non-rebreathing anaesthetic systems have been developed for human anaesthesia. This study evaluated a New Zealand designed non-rebreathing circuit, the Palmerston Valve, in anaesthetised spontaneously breathing dogs and compared it to the widely used Lack coaxial circuit. Arterial blood gas measurements 60 minutes after induction demonstrated comparable slight increases in PaCO2 in nearly all dogs maintained on the Palmerston Valve and Lack coaxial circuit with halothane and oxygen mixtures, and a fresh gas flow rate of 70 ml/kg/min. Results suggest the Palmerston Valve is at least as efficient as the Lack coaxial circuit, while offering in the same unit the potential for economical controlled ventilation.     

The EMO system in small animal anaesthesia

The EMO System was used to administer ether/air anaesthesia to dogs undergoing clinical surgical procedures. Anaesthesia with spontaneous breathing gave rise to normal oxygen tensions in arterial blood, a slight acidosis and a decrease in arterial carbon dioxide tension. When used with relaxant drugs and intermittent positive pressure ventilation of the lungs it was found that to maintain normal oxygen tensions in the arterial blood it was necessary to hyperventilate to low arterial carbon dioxide tensions. Ether/air anaesthesia with the EMO System was found to meet modern criteria for acceptability in general practice where the veterinary surgeon may be assisted in the operating theatre by a nurse or may be entirely alone.     

Evaluation of a non-rebreathing circuit for small animal anaesthesia

Several new multi-purpose non-rebreathing anaesthetic systems have been developed for human anaesthesia. This study evaluated a New Zealand designed non-rebreathing circuit, the Palmerston Valve, in anaesthetised spontaneously breathing dogs and compared it to the widely used Lack coaxial circuit. Arterial blood gas measurements 60 minutes after induction demonstrated comparable slight increases in PaCO₂ in nearly all dogs maintained on the Palmerston Valve and Lack coaxial circuit with halothane and oxygen mixtures, and a fresh gas flow rate of 70 ml/kg/min.

Results suggest the Palmerston Valve is at least as efficient as the Lack coaxial circuit, while offering in the same unit the potential for economical controlled ventilation.     

PROPOFOL INFUSION ANAESTHESIA IN DOGS

Studies were carried out on 40 dogs premedicated with acepromazine (0.05 mg kg^-1), and atropine (0.02 mg kg^-1) to determine the minimum infusion rate of propofol needed to maintain anaesthesia and to compare the quality of the anaesthesia with that produced by halothane/nitrous oxide/oxygen. An infusion rate of 0.4 mg kg^-1 min^-1 of propofol produced surgical anaesthesia in dogs breathing oxygen or oxygen-enriched air. Cardiovascular and respiratory effects were similar to those in dogs anaesthetized with halothane/nitrous oxide and with both anaesthetic regimes myocardial oxygen consumption appeared to increase with increasing duration of anaesthesia. Propofol infusion was associated with a 16 per cent incidence of vomiting in the recovery period. Maintenance of anaesthesia in healthy dogs by the continuous infusion of propofol appeared to be safe but less satisfactory than the use of halothane/nitrous oxide.     

The influence of ventilation mode (spontaneous ventilation, IPPV and PEEP) on cardiopulmonary parameters in sevoflurane anaesthetized dogs

The purpose of this study was to investigate the cardiopulmonary influences of sevoflurane in oxygen at two anaesthetic concentrations (1.5 and 2 MAC) during spontaneous and controlled ventilation in dogs. After premedication with fentany-droperidol (5 microg/kg and 0.25 mg/kg intramuscularly) and induction with propofol (6 mg/kg intravenously) six dogs were anaesthetized for 3 h. Three types of ventilation were compared: spontaneous ventilation (SpV), intermittent positive pressure ventilation (IPPV), and positive end expiratory pressure ventilation (PEEP, 5 cm H2O). Heart rate, haemoglobin oxygen saturation, arterial blood pressures, right atrial and pulmonary arterial pressures, pulmonary capillary wedge pressure and cardiac output were measured. End tidal CO2%, inspiratory oxygen fraction, respiration rate and tidal volume were recorded using a multi-gas analyser and a respirometer. Acid-base and blood gas analyses were performed. Cardiac index, stroke volume, stroke index, systemic and pulmonary vascular resistance, left and right ventricular stroke work index were calculated. Increasing the MAC value during sevoflurane anaesthesia with spontaneous ventilation induced a marked cardiopulmonary depression; on the other hand, heart rate increased significantly, but the increases were not clinically relevant. The influences of artificial respiration on cardiopulmonary parameters during 1.5 MAC sevoflurane anaesthesia were minimal. In contrast, PEEP ventilation during 2 MAC concentration had more pronounced negative influences, especially on right cardiac parameters. In conclusion, at 1.5 MAC, a surgical anaesthesia level, sevoflurane can be used safely in healthy dogs during spontaneous and controlled ventilation (IPPV and PEEP of 5 cm H2O).     

Low flow anaesthesia with isoflurane in the dog

The aim of the present study was to compare the safety of two low flow (LF) regimes [fresh gas flow (FGF) 20 ml/kg/min (group 2) and 14 ml/kg/min (group 3)] with the high flow (HF) technique (FGF 50 ml/kg/min; group 1) of isoflurane anaesthesia. Data were gathered from ninety dogs assigned for surgery under general anaesthesia with an expected duration of 75 minutes or longer. All dogs had an anaesthetic induction with 0,6 mg/kg I-methadone (maximum 25 mg) and 1 mg/kg diazepam (maximum 25 mg) i.v. Anaesthesia was maintained with isoflurane in a mixture of 50% O2 and 50% N2O as carrier gases, with controlled ventilation. The Monitoring included electrocardiogramm, body temperature, the temperature of in- and exspired gases, arterial oxygen saturation, arterial blood pressure as well as a continuous monitoring of inhaled and exhaled gas concentrations (O2, N2O, CO2, isoflurane). The consumption of isoflurane and carrier gases as well as the recovery times were evaluated for the three groups. The inspired oxygen concentrations always ranged above the minimum value of 30 Vol.-% during low flow anaesthesia. The arterial oxygen saturation ranged between 92-98%, the end tidal concentration of CO2 between 35 and 45 mmHg. Heart rate and arterial blood pressure were within normal limits. Recovery time was significantly shorter after LF than after HF anaesthesia. The highest decrease in body temperature occurred in the HF group 1 because of a significantly lower anaesthetic gas temperature. Despite this, LF anaesthesia resulted in a reduced consumption of carrier gases and volatiles. In conclusion, low flow anaesthesia with isoflurane is a safe technique and offers substantial economic advantages over high flow techniques and is moreover better tolerated by the patients.     

Anti-nociceptive and sedative effects of sufentanil long acting during and after sevoflurane anaesthesia in dogs

The purpose of the present study was to determine the most effective time interval between the administration of sufentanil long acting (LA) and the induction of sevoflurane anaesthesia in dogs. The occurrence of sedation, analgesia and other marked side-effects were evaluated in addition to the possible dosage-reducing effect of sufentanil on sevoflurane in dogs. Forty clinically normal beagles aged 1-2 years and weighing between 8.4 and 13.6 kg were included. Two control groups were used: one group of dogs (A) received sufentanil LA (50 microg/kg i.m.) and a second group (B) the sufentanil vehicle followed by standard inhalation anaesthesia of 90 min. After premedication with sufentanil LA immediately before (C0), 15 min (D15) or 30 min (E30) prior to induction with thiopental (i.v.) the dogs were anaesthetized for 90 min with sevoflurane in oxygen. Pain and sedation scores were evaluated every 10 min during sevoflurane anaesthesia and at 2 (T120), 4 (T240) and 24 h (T1440) after initiation of anaesthesia. The occurrence of adverse reactions such as hypothermia, lateral recumbency, ataxia, noise sensitivity, vomiting, defaecation, salivation, nystagmus and excitation was observed at the same time-points. During the recovery period pain scores were lower and sedation scores higher in the sufentanil LA groups. In many dogs acceptable pain and sedation scores persisted during 24 h. Several dogs showed ataxia, lateral recumbency, arousal on auditory stimulation, defaecation, salivation and excitation at several time-points after sufentanil LA administration. Sufentanil LA in addition to sevoflurane anaesthesia offered beneficial dosage-reducing analgesic effects up to 69.8% for thiopental and 78.3% for sevoflurane; although several typical opioid side-effects occurred. To achieve this advantageous dosage-reducing effect 15 min should be respected between sufentanil LA administration and induction of sevoflurane anaesthesia.     

Comparative study of propofol or propofol and ketamine for the induction of anaesthesia in dogs

The effects of propofol alone or propofol and ketamine for the induction of anaesthesia in dogs were compared. Thirty healthy dogs were premedicated with acepromazine and pethidine, then randomly allocated to either treatment. Anaesthesia was induced with propofol (4 mg/kg bodyweight intravenously) (group 1), or propofol and ketamine (2 mg/kg bodyweight of each intravenously) (group 2). Anaesthesia was maintained with halothane, delivered in a mixture of oxygen and nitrous oxide (1:2) via a non-rebreathing Bain circuit. Various cardiorespiratory parameters were monitored at two, five, 10, 15, 20, 25 and 30 minutes after induction, and the animals were observed during anaesthesia and recovery, and any adverse effects were recorded. During anaesthesia, the heart rate, but not the systolic arterial pressure, was consistently higher in group 2 (range 95 to 102 beats per minute) than in group 1 (range 73 to 90 beats per minute). Post-induction apnoea was more common in group 2 (11 of 15) than in group 1 (six of 15). Muscle twitching was observed in three dogs in each group. Recovery times were similar in both groups. Propofol followed by ketamine was comparable with propofol alone for the induction of anaesthesia in healthy dogs.     

Cardiopulmonary effects of medetomidine or midazolam in combination with ketamine or tiletamine/zolazepam for the immobilisation of captive cheetahs (Acinonyx jubatus)

Captive cheetah (Acinonyx jubatus) scheduled for either general health examination or dental surgery were immobilised with combinations of medetomidine-ketamine (K/DET, n = 19), midazolam-ketamine (K/MID, n = 4) or medetomidine-tiletamine-zolazepam (Z/DET, n = 5). Induction time and arterial blood pressure was not statistically significantly (P > 0.05) different between treatment groups. Transient seizures were observed in the K/DET treated animals during induction. Hypertension was present in all groups during anaesthesia with mean (+/- SD) systolic pressure of 30.7 +/- 5.0 kPa for the K/DET group, 27.7 +/- 2.7 kPa for the K/MID group, and 33.1 +/- 4.6 kPa for the Z/DET group. Heart rate was statistically significantly (P < 0.05) lower in the K/DET group (69 +/- 13.2 beats/min) compared to the K/MID group (97 +/- 22.6 beats/min), and ventilation rate was statistically significantly (P < 0.05) lower in the K/MID group (15 +/- 0.0 breaths/min) compared with the K/DET group (21 +/- 4.6). A metabolic acidosis and hypoxia were observed during anaesthesia when breathing air. Oxygen (O2) administration resulted in a statistically significant (P < 0.05) increase in the arterial partial pressure of carbon dioxide (hypercapnoea), arterial partial pressure of O2, and % oxyhaemoglobin saturation.     

Routine veterinary anaesthetic management practices in South Africa

A survey of the routine anaesthetic management of dogs and cats during sterilisation by veterinarians in South Africa was conducted. This report describes the premedication, induction and maintenance agents most commonly used in dogs and cats. Information about monitoring of patients during the procedure and who is responsible for induction of anaesthesia and monitoring was obtained. Questionnaires were analysed with regard to demographic data, practice size, continuing education, the number of surgical procedures and sterilisations performed per week and an estimate of yearly mortality. Acetylpromazine is the most commonly used premedication in dogs and xylazine in cats. Thiopentone in dogs and alphaxalone/alphadolone in cats were the induction agents most commonly used. Alphaxalone/alphadolone in cats and halothane in dogs are the most commonly used maintenance agents. Records of anaesthesia are poorly kept and monitoring of patients is poorly performed. Respiratory rate is the parameter most commonly monitored (90.7%), and in most cases is the sole parameter. On average 10.34 +/- 8.25 cats were operated per week, of which 5.45 +/- 5.60 were sterilised; 17.79 +/- 11.61 dogs were operated per week, of which 8.65 +/- 7.10 were sterilised. In total, 190 patients died under anaesthesia, a mortality rate of 1:1,243. Just over 50% of practitioners had attended continuing education courses during their careers.