Outcome and radiographic assessment of the development of osteoarthritis in 15 horses with rupture of collateral ligaments and joint instability in metacarpophalangeal or metatarsophalangeal joints

In this study, the long-term outcome and the development of osteoarthritis (OA) after collateral ligament (CL) rupture in metacarpophalangeal (MCP) or metatarsophalangeal (MTP) joints with either open or closed MCP / MTP joints was evaluated. Horses were included in the study on the basis of radiographic evidence of subluxation or luxation in stressed MCP / MTP joints in the dorsopalmar / dorsoplantar (DP) view. Horses were clinically and radiographically evaluated at first presentation in the clinc as well as at follow-up examination. Fifteen horses met the inclusion criteria. Lameness varied between 2 / 5 to non-weightbearing lameness. Three horses presented with a clinically severely instable fetlock. Opening of the MCP / MTP joint as consequence of associated wounds or lacerations was diagnosed in 4 horses. In 11 horses CL rupture without opening of the associated MCP / MTP joint was diagnosed (no wounds communicating with the MCP / MTP joint). Six of these horses were treated conservatively, 5 were treated surgically. Three months after admission 11 horses were sound at walk and trot. Three horses showed a grade 3-4 / 5 lameness. One of these was euthanatized 6 weeks later because severe OA had developed in the injured MTP joint. Another horse had been euthanized because of laminitis. In 12 horses long-term follow-up examination (9 months – 12 years) was possible. All horses showed radiographic signs of OA in the affected MCP / MTP joint. In 6 horses there was also mild to moderate OA in the PIP joint of the affected limb. 67% (n = 10) of the horses returned to be used for pleasure riding as prior to injury, 13% (n = 2) of the horses remained pasture sound, 20% (n=3) were euthanatized because of persistent lameness. The study shows the long-term prognosis of CL ruptures with open and closed MCP / MTP joints. In horses with chronic lamness after CL rupture in MCP / MTP joint the PIP joint should also be considerd as a potential source of pain

Effect of contrast medium injection duration on peak enhancement of canine pulmonary arteries

Our goal was to investigate the effect of contrast medium injection duration on pulmonary artery peak enhancement and time to peak enhancement. Fourteen dogs were allocated into one of seven predefined weight categories, each category contained two dogs. Dogs in each weight category were assigned to group A or B. Animals in each group received a different contrast medium injection protocol. In group A, a fixed injection rate of 5ml/s was used. In group B, the contrast injection rate was calculated as follows: flow rate1⁄4contrast volume/scan durationþ10s. Time to peak enhancement and peak enhancement of the main left and right pulmonary arteries were measured on single-level, dynamic CT images for a fixed time of 30 s. Rank correlation (Spearman’s) coefficients between injection duration and time to peak enhancement and between body weight and peak enhancement were calculated. For group A, there was a significant negative correlation between peak enhancement and weight (r1⁄

Comparison of a new metamizole formulation and carprofen for extended post-operative analgesia in dogs undergoing ovariohysterectomy

A newly developed slow-release tablet formulation of metamizole was compared with carprofen for post-operative analgesia in dogs undergoing ovariohysterectomy. Twenty-three dogs were randomly assigned to one of two groups, and administered 50 mg/kg metamizole PO (Group M) or 4 mg/kg carprofen PO (Group C) 1 h before anaesthetic induction and 24 and 48 h later. Anaesthesia was induced with propofol and maintained with isoflurane and fentanyl, after premedication with 0.005 mg/kg medetomidine and 0.3 mg/kg methadone IM. A blinded observer assessed post-operative sedation, and analgesia using a visual analogue scale, a dynamic interactive visual analogue scale, the Glasgow composite pain scale (GCPS), and a mechanical nociceptive threshold device (T = 0.5, 1, 2, 4, 8, 12, 18, 21, 24, 36, 45, 60 and 70 h after surgery). Rescue methadone was administered if the GCPS was >6/24 in ambulatory dogs, or >5/20 in non-ambulatory dogs. Plasma concentrations of test drugs were quantified. The dose range for metamizole was 39-56 mg/kg. At T = 0.5 h sedation scores were significantly higher in Group C and GCPS scores were significantly higher in Group M. Three dogs required rescue methadone (Group M, n = 1; Group C, n = 2). Vomiting occurred post-operatively in 45% of dogs in Group M. Carprofen and metamizole were both well absorbed; peak concentrations occurred within 4-24 h, and 4-16 h for carprofen and metamizole, respectively. Both drugs provided adequate analgesia of similar duration. No side effects were observed with carprofen while vomiting was frequent following administration of metamizole

Comparison of intraperitoneal ropivacaine and bupivacaine for postoperative analgesia in dogs undergoing ovariohysterectomy

Objective: To compare postoperative analgesia following either intraperitoneal (IP) ropivacaine or bupivacaine in dogs undergoing ovariohysterectomy (OVH) in the scope of multimodal analgesia. Study design: Prospective, randomized, blinded clinical study. Animals: A total of 45 privately owned dogs undergoing OVH, aged 37 \ub1 28 months and weighing 11.3 \ub1 4.5 kg. Methods: Dogs were premedicated with acepromazine (0.05 mg kg 121) and morphine (0.5 mg kg 121) intramuscularly (IM). Anaesthesia was induced with alfaxalone and maintained with isoflurane in oxygen. Carprofen (4 mg kg 121) was injected subcutaneously after intubation. Dogs were randomly assigned to receive either bupivacaine (group B; 3 mg kg 121) or ropivacaine (group R; 3 mg kg 121) IP prior to complete closure of the linea alba. At 0.5, 1, 2, 4, 6 and 8 hours after extubation, sedation and postoperative pain were assessed, using the short form of the Glasgow Composite Pain scale (GCPS-SF), a dynamic interactive visual analogue scale (DIVAS), and mechanical nociceptive threshold (MNT) measurement. Rescue morphine (0.2 mg kg 121) was administered in case of 65 5/20 or 65 6/24 in the GCPS-SF and/or >40 mm in the DIVAS. Parametric data were compared using the t test; nonparametric data were analysed with the two-sample Wilcoxon test (p < 0.05). Results: The GCPS-SF score was significantly higher in group R at 8 hours. There was no other significant difference regarding sedation or analgesia between the groups. Rescue analgesia was administered to 15 dogs (R: 9/22; B: 6/22), with no significant difference between the groups. MNT values decreased in both groups at all time points when compared to baseline. No adverse effects were observed. Conclusions and clinical relevance: Ropivacaine or bupivacaine IP in combination with morphine IM and carprofen SC provided comparable postoperative analgesia in dogs after OVH for 6 hours. However, the anaesthetic protocol used did not prevent the administration of rescue analgesia in 41% of animals

Intraperitoneal bupivacaine with or without incisional bupivacaine for postoperative analgesia in dogs undergoing ovariohysterectomy

OBJECTIVE: Intraperitoneal (IP) bupivacaine provides postoperative analgesia in dogs undergoing ovariohysterectomy (OHE) alone or in combination with incisional (INC) bupivacaine. This study investigated whether the combination of INC and IP bupivacaine is superior to IP bupivacaine alone. STUDY DESIGN: Prospective, randomized, blinded clinical study. ANIMALS: Thirty-nine privately owned dogs undergoing OHE, aged 25 ± 23 months and weighing 11.8 ± 5.7 kg. METHODS: Dogs were premedicated with acepromazine (0.05 mg kg-1 ) and morphine (0.5 mg kg-1 ) intramuscularly (IM); anaesthesia was induced with propofol and maintained with isoflurane in oxygen. Carprofen (4 mg kg-1 ) was administered subcutaneously (SC) after intubation. Bupivacaine (3 mg kg-1 ) IP was administered before complete closure of the linea alba to all dogs. Dogs were randomly assigned into two groups: group B received bupivacaine (n = 20; 1 mg kg-1 ) and group S received saline (n = 19; 0.2 mL kg-1 ) INC as a subcutaneous 'splash' before skin closure. Postoperative analgesia was assessed with a dynamic interactive visual analogue scale, the short form of the Glasgow Composite Pain Scale, and mechanical nociceptive threshold (MNT) measurement at 0.5, 1, 2, 4, 6, 8, 12 and 20 hours after surgery by one blinded observer. Parametric data were tested using t-test; nonparametric data were analysed using the two-sample Wilcoxon test (p < 0.05). RESULTS: There was no significant difference between groups with regard to age, weight, surgical and anaesthetic duration, incision length, sedation and pain scores. MNT values decreased in both groups at all time points as compared with the baseline. No dog required rescue analgesia. No postoperative complications were observed. CONCLUSION AND CLINICAL RELEVANCE: Bupivacaine IP and carprofen SC after morphine IM did provide satisfactory postoperative analgesia in dogs undergoing OHE with the anaesthetic protocol used. There appears to be no clinical advantage to adding bupivacaine INC. Neither protocol could prevent the development of primary hyperalgesia

A clinical comparison of two anaesthetic protocols using lidocaine or medetomidine in horses

Objective: To compare the effects of two balanced anaesthetic protocols on end-tidal isoflurane (Fe′ISO), cardiopulmonary performance and quality of recovery in horses. Design: Prospective blinded randomized clinical study. Animals: Sixty-nine client-owned horses, American Society of Anesthesiologists category I and II, undergoing elective surgery. Methods: The horses were premedicated with acepromazine (0.03 mg kg−1) IM 30–60 minutes before induction of anaesthesia and were randomly assigned to one of two treatments: in group L (37 horses) xylazine (1 mg kg−1) and in group M (31 horses) medetomidine (7 μg kg−1) was administered IV for sedation. Anaesthesia was induced 5 minutes later with ketamine (2.2 mg kg−1) and diazepam (0.02 mg kg−1) IV and maintained with isoflurane in oxygen/air (initial FIO2 0.40–0.50) and a constant rate infusion (CRI) of either lidocaine (2 mg kg−1/15 minutes loading dose followed by 50 μg kg−1 minute−1) (group L) or medetomidine (3.5 μg kg−1 hour−1) (group M). If horses showed movement or nystagmus, additional thiopental or ketamine was administered. Heart rate, mean arterial pressure (MAP), Fe′ISO and arterial blood gases were measured. Cardiac output was measured with the lithium dilution method in 10 (group L) and 11 (group M) horses every 45 minutes. Recovery was scored. Results: Heart rate and the cardiac index (CI) were significantly higher in group L with changes over time. In group M, MAP was significantly higher during the first 50 minutes. Group L needed more additional ketamine and thiopental to maintain a surgical plane of anaesthesia and Fe′ISO was significantly higher from 70 minutes. Recovery was longer in group M and of better quality. The significance level was set at p < 0.05. Conclusions and clinical relevance: In group M, maintenance of stable anaesthetic depth was easier and lower Fe′ISO was required to maintain a surgical plane of anaesthesia. Recoveries were longer but of better quality. The CI was higher in group L but cardiovascular function was generally well maintained in both groups

Total intravenous anaesthesia in horses using medetomidine and propofol

Objective: To examine the clinical suitability of medetomidine–propofol infusions for total intravenous anaesthesia in horses. Animals: Fifty client-owned horses of mixed breed, age [mean ± SD (range)] 6.6 ± 4.4 (0.04–18) years, mass 478 ± 168.3 (80–700) kg presented for a range of operations requiring general anaesthesia. Materials and methods: Pre-anaesthetic medication was intravenous (IV) medetomidine 7 μg kg−1. Anaesthesia was induced with IV ketamine (2 mg kg−1) and diazepam (0.02 mg kg−1). After endotracheal intubation, O2 was delivered (FiO2 > 0.85). Positive pressure ventilation was initiated if breath-holding in excess of 1 minute occurred. Anaesthesia was maintained with a constant rate medetomidine infusion (3.5 μg kg−1 hour−1) and propofol infused IV to effect (initial dose 0.1 mg kg−1 minute−1). Heart (HR) respiratory (fr) and propofol administration rates, and systemic arterial blood pressures were recorded at 5-minute intervals. Arterial blood gas (O2 and CO2) tensions and pH values were recorded every 15 minutes. Ten minutes after ending medetomidine–propofol infusion, medetomidine (2 μg kg−1; IV) was given. Cardiopulmonary data were analysed using descriptive statistical techniques. Results: Thirty-three orthopaedic, seven integumentary and 10 elective abdominal operations were performed. Cardiopulmonary data, presented as range of mean individual (and absolute individual minimum and maximum values) were: HR: 28.0–39.2 (16–88) beats minute−1; mean arterial blood pressure: 74.0–132.5 (42–189) mmHg; PaO2: 22.1–42.9 (4.9–67.8) kPa; [166–322 (37–508) mmHg], PaCO2: 6.7–8.1 (4.2–11.8) kPa [50–61 (32–88) mmHg] and pH 7.35–7.39 (7.15–7.48). Positive pressure ventilation was required in 23 horses. In three horses, HR values below 20 beats minute−1 were treated with 20 μg kg−1 atropine (IV). Mean propofol infusion rates were 98–108 μg kg−1 minute−1. During anaesthesia, movement occurring in 14 horses was controlled with thiopental. Duration of anaesthesia was 111.6 ± 41.4 (46–225) minutes. Recovery in all horses was uneventful and completed within 42.2 ± 19.8 (12–98) minutes. Conclusions and clinical relevance: Medetomidine–propofol infusion produces adequate conditions for a range of surgical procedures. Cardiovascular function was adequate, as no pressor agents were required. Positive pressure ventilation was required in 23 horses

Minimum infusion rate of alfaxalone for total intravenous anaesthesia after sedation with acepromazine or medetomidine in cats undergoing ovariohysterectomy

Objective: To determine the induction doses, then minimum infusion rates of alfaxalone for total intravenous anaesthesia (TIVA), and subsequent, cardiopulmonary effects, recovery characteristics and alfaxalone plasma concentrations in cats undergoing ovariohysterectomy after premedication with butorphanol-acepromazine or butorphanol-medetomidine. Study design: Prospective randomized blinded clinical study. Animals: Twenty-eight healthy cats. Methods: Cats undergoing ovariohysterectomy were assigned into two groups: together with butorphanol [0.2 mg kg−1 intramuscularly (IM)], group AA (n = 14) received acepromazine (0.1 mg kg−1 IM) and group MA (n = 14) medetomidine (20 μg kg−1 IM). Anaesthesia was induced with alfaxalone to effect [0.2 mg kg−1 intravenously (IV) every 20 seconds], initially maintained with 8 mg kg−1 hour−1 alfaxalone IV and infusion adjusted (±0.5 mg kg−1 hour−1) every five minutes according to alterations in heart rate (HR), respiratory rate (fR), Doppler blood pressure (DBP) and presence of palpebral reflex. Additional alfaxalone boli were administered IV if cats moved/swallowed (0.5 mg kg−1) or if fR >40 breaths minute−1 (0.25 mg kg−1). Venous blood samples were obtained to determine plasma alfaxalone concentrations. Meloxicam (0.2 mg kg−1 IV) was administered postoperatively. Data were analysed using linear mixed models, Chi-squared, Fishers exact and t-tests. Results: Alfaxalone anaesthesia induction dose (mean ± SD), was lower in group MA (1.87 ± 0.5; group AA: 2.57 ± 0.41 mg kg−1). No cats became apnoeic. Intraoperative bolus requirements and TIVA rates (group AA: 11.62 ± 1.37, group MA: 10.76 ± 0.96 mg kg−1 hour−1) did not differ significantly between groups. Plasma concentrations ranged between 0.69 and 10.76 μg mL−1. In group MA, fR, end-tidal carbon dioxide, temperature and DBP were significantly higher and HR lower. Conclusion and clinical relevance: Alfaxalone TIVA in cats after medetomidine or acepromazine sedation provided suitable anaesthesia with no need for ventilatory support. After these premedications, the authors recommend initial alfaxalone TIVA rates of 10 mg kg−1 hour−1