J.H. Burford

Prospective survey of veterinary practitioners’ primary assessment of equine colic: clinical features, diagnoses, and treatment of 120 cases of large colon impaction

BackgroundLarge colon impactions are a common cause of colic in the horse. There are no scientific reports on the clinical presentation, diagnostic tests and treatments used in first opinion practice for large colon impaction cases. The aim of this study was to describe the presentation, diagnostic approach and treatment at the primary assessment of horses with large colon impactions.MethodsData were collected prospectively from veterinary practitioners on the primary assessment of equine colic cases over a 12 month period. Inclusion criteria were a diagnosis of primary large colon impaction and positive findings on rectal examination. Data recorded for each case included history, signalment, clinical and diagnostic findings, treatment on primary assessment and final case outcome. Case outcomes were categorised into three groups: simple medical (resolved with single treatment), complicated medical (resolved with multiple medical treatments) and critical (required surgery, were euthanased or died). Univariable analysis using one-way ANOVA and Tukey’s post-hoc test, Kruskal Wallis with Dunn’s post-hoc test and Chi squared analysis were used to compare between different outcome categories.Results1032 colic cases were submitted by veterinary practitioners: 120 cases met the inclusion criteria for large colon impaction. Fifty three percent of cases were categorised as simple medical, 36.6% as complicated medical, and 9.2% as critical. Most cases (42.1%) occurred during the winter. Fifty nine percent of horses had had a recent change in management, 43% of horses were not ridden, and 12.5% had a recent / current musculoskeletal injury. Mean heart rate was 43bpm (range 26-88) and most cases showed mild signs of pain (67.5%) and reduced gut sounds (76%). Heart rate was significantly increased and gut sounds significantly decreased in critical compared to simple medical cases (p<0.05). Fifty different treatment combinations were used, with NSAIDs (93%) and oral fluids (71%) being administered most often.ConclusionsLarge colon impactions typically presented with mild signs of colic; heart rate and gut sounds were the most useful parameters to distinguish between simple and critical cases at the primary assessment. The findings of seasonal incidence and associated management factors are consistent with other studies. Veterinary practitioners currently use a wide range of different treatment combinations for large colon impactions.

Investigating medetomidine-buprenorphine as preanaesthetic medication in cats.

OBJECTIVES The objective of this study was to investigate medetomidine-buprenorphine preanaesthetic medication in cats. METHODS Forty American Society of Anesthesiologists (ASA) I female cats were enrolled in this prospective, blinded, clinical study. Cats were randomised into one of four groups: group M30 were injected intramuscularly with 30 microg/kg medetomidine, groups M10+B, M30+B and M50+B received 10, 30 and 50 microg/kg of medetomidine, respectively, each in combination with 20 microg/kg buprenorphine. After 30 minutes, a sedation score was allocated. Anaesthesia was induced using intravenous propofol and maintained using isoflurane in oxygen, while cats underwent ovariohysterectomy. Heart rate, respiratory rate, end-tidal carbon dioxide tension and oxygen saturation of haemoglobin were recorded. Atipamezole was administered intramuscularly at volatile agent discontinuation. Time taken to lift their head, sit in sternal and stand were recorded along with quality of recovery. RESULTS M30+B cats required significantly less isoflurane compared with M30 cats. Heart rate and oxygen saturation of haemoglobin were significantly lower in M50+B cats than in M30 cats. All M+B groups experienced significantly better recoveries compared with the medetomidine only M30 control group. CLINICAL SIGNIFICANCE The addition of buprenorphine to medetomidine preanaesthetic medication in cats reduces volatile agent vaporiser setting and improves the quality of recovery from anaesthesia.

Measurement of respiratory system compliance and respiratory system resistance in healthy dogs undergoing general anaesthesia for elective orthopaedic procedures

OBJECTIVE The aim of this study was to investigate normal values for the dynamic compliance of the respiratory system (Crs) and respiratory system resistance (Rrs) in mechanically ventilated anaesthetized dogs. STUDY DESIGN Prospective clinical study. ANIMALS Forty healthy dogs undergoing elective orthopaedic surgery. Body weight was (mean ± SD) 26.8 ± 10.7 kg (range: 1.9-45.0 kg), age 4.7 ± 2.9 years (range: 0.1-10.6 years). METHODS Dogs were premedicated with acepromazine and methadone administered intramuscularly and anaesthesia induced with propofol intravenously. After endotracheal intubation the dogs lungs were connected to an appropriate breathing system depending on body weight and isoflurane in oxygen administered for maintenance of anaesthesia. The lungs were ventilated mechanically with variables set to maintain normocapnia (end-tidal carbon dioxide concentration 4.7-6.0 kPa). Peak inspiratory pressure, Crs, Rrs, tidal volume, respiratory rate and positive end-expiratory pressure were recorded at 5, 30, 60, 90 and 120 minutes after start of mechanical ventilation. Cardiovascular variables were recorded at time of collection of respiratory data. RESULTS General additive modeling revealed the following relationships: Crs =[0.895 × body weight (kg)] + 8.845 and Rrs=[-0.0966 × body weight (kg)] + 6.965. Body weight and endotracheal tube diameter were associated with Crs (p<0.001 and p=0.002 respectively) and Rrs (p=0.017 and p=0.002 respectively), body weight being linearly related to Crs and inversely to Rrs. CONCLUSION AND CLINICAL RELEVANCE Body weight was linearly related to Crs while Rrs has an inverse linear relationship with body weight in mechanically ventilated dogs. The derived values of Crs and Rrs may be used for monitoring of lung function and ventilation in healthy dogs under anaesthesia.

Cutaneous fungal granuloma in a horse

This case report describes a 4-year-old-horse with two cutaneous masses on the right crest of the neck. Biopsy revealed chronic nodular pyogranulomatous dermatitis and panniculitis. Giemsa and periodic acid-Schiff stains showed focal spherical, yeast-like organisms. A diagnosis of cutaneous fungal granuloma was made. The size of the masses decreased after oral treatment with fluconazole for 10 days combined with potassium iodide for 30 days, and the remaining masses were excised by laser. Lesions did not recur at the site. Fungal granuloma should be considered as a differential diagnosis in horses with cutaneous or subcutaneous nodules. A definitive diagnosis can only be achieved by histopathological examination or by culture of the affected tissue.

Does pethidine affect the cardiovascular and sedative effects of dexmedetomidine in dogs

OBJECTIVES To investigate pethidines effects on sedation and cardiovascular variables in dogs premedicated with dexmedetomidine. METHODS Sixty American Society of Anesthesiologists (ASA) I dogs were presented for routine neutering. Heart rate was measured at admission. Dogs were randomly assigned to one of the five groups to decide premedication; group D5+P (dexmedetomidine 5 microg/kg plus pethidine 5 mg/kg), D10+P (dexmedetomidine 10 microg/kg plus pethidine 5 mg/kg) with three control groups, D5 (dexmedetomidine 5 microg/kg), D10 (dexmedetomidine 10 microg/kg) or P (pethidine 5 mg/kg). Heart rate was measured at 3, 5, 10 and 20 minutes after preanaesthetic medication. Simple descriptive scores for sedation were assigned after 20 minutes. Anaesthesia was induced using propofol and maintained using isoflurane in oxygen. Heart rate was recorded throughout anaesthesia. RESULTS Sedation scores after preanaesthetic medication were significantly higher (P<0.001) in groups D5+P and D10+P compared with the other three groups. D5+P and D10+P groups tended to have lower heart rates in dogs at all time points after premedication compared with groups containing only pethidine or dexmedetomidine at the relevant dose. CLINICAL SIGNIFICANCE Greater sedation is achieved using combinations of dexmedetomidine and pethidine compared with each drug alone. Pethidine does not attenuate the alpha-2 adrenergic-induced bradycardia.

Use of ethanol in the treatment of distal tarsal joint osteoarthritis: 24 cases

UNLABELLED REASONS FOR PERFORMING THIS STUDY: Intra-articular ethanol has been described to promote distal tarsal joint ankylosis. Its use and results in clinical cases affected by osteoarthritis (OA) have not been reported. OBJECTIVES To describe and evaluate the results of treatment of distal tarsal joint OA by facilitated ankylosis stimulated by intra-articular ethanol injection. METHODS Twenty-four horses met the inclusion criteria of tarsometatarsal and centrodistal joint OA diagnosed by a positive response to intra-articular analgesia, radiographic evaluation and recurrence of lameness ≤ 4 months after intra-articular medication with a corticosteroid. Horses were sedated and, following a radiographic contrast study of the tarsometatarsal joint, medication with 2-4 ml of either 100% pure ethanol (G100) or a 70% ethanol (G70) solution was applied. Horses were classified as improved based on a 50% reduction from initial lameness grade combined with an increase in exercise level. RESULTS Of the 24 horses included in this study, 20 had the treatment performed bilaterally and 4 unilaterally. All horses were available for initial follow-up examination and 21 for a second one 6-9 months after treatment. This represented a total of 44 treated limbs and 35 available for long-term follow-up. Of these, 21/35 (60%) were considered improved, which corresponds to 11/21 horses (52%). Of 21 horses, 4 (19%) deteriorated and 2 of these developed significant complications related to treatment. CONCLUSIONS Distal tarsal joint ankylosis with ethanol should be considered a safe and economic treatment in cases of distal tarsal joint OA that fail to show long-term improvement with intra-articular corticosteroid treatment. POTENTIAL RELEVANCE Ethanol should be considered in the treatment of certain cases of distal tarsal joint OA. The importance of performing an adequate radiographic contrast study of the tarsometatarsal joint prior to treatment is highlighted.

Diagnosis of colic

Equine colic is the most common type of emergency seen by first-opinion veterinary practices. However, the primary assessment of horses with colic can be fraught with difficulties due to the vast array of aetiologies and accompanying clinical signs associated with this condition. The Nottingham Equine Colic Project has been collaborating with veterinary …

Veterinary practitioners’ selection of diagnostic tests for the primary evaluation of colic in the horse

The aim of this study was to survey veterinary practitioners’ selection of diagnostic tests for horses with clinical signs of abdominal pain. A questionnaire was distributed to veterinary surgeons involved in the primary evaluation of horses with abdominal pain, including the respondents demographics, selection of diagnostic tests and factors affecting decision-making. Data analysis included descriptive analysis, categorisation of free text and simple univariable correlations to explore the relationships between independent variables and the relative self-estimated frequency that diagnostic tests were performed. A total of 228 responses were analysed. Participants worked in mixed practice (55.7 per cent), first opinion equine (22.8 per cent), first and second opinion equine (17.9 per cent) and referral practice (3.1 per cent). The majority (48.2 per cent, 105/218) were very confident managing a colic case (confidence level 4/5). The most frequently used diagnostic tests were ‘response to analgesia’ (87.2±24.0 per cent cases), rectal examination (75.9±21.2 per cent) and nasogastric intubation (43.8±27.6 per cent). Approach varied between practitioners, and for all diagnostic tests with frequency of use ranging from 0 to 100 per cent of cases. ‘Risk to personal safety’ was the most common reason for not using rectal examination. Practitioners opinion of their confidence level in managing a colic case was associated with how frequently they used different diagnostic tests. There was marked variation in practitioners’ approaches, highlighting the need for further evidence to support decision-making.