112


EQUINE VETERINARY EDUCATION / AE / MARCH 2015


Pain scores increased for 12 h after surgery in the control


group and were significantly higher than in the morphine group for the first 6 h. Pain scores remained unaltered in the morphine group throughout the observation period. Heart rate and plasma cortisol concentrations did not differ between groups or with time. No signs of colic were observed in any horse. The authors concluded that the doses of epidural morphine used in this study did not adversely affect GI motility in horses after laparoscopic surgery under general anaesthesia.


Colonic sand accumulation treatments


In this study, Kati Niinistö and colleagues in Finland and Estonia have compared the effects of enteral psyllium mucilloid (psyllium), magnesium sulphate (MgSO4) and a combination of MgSO4 and psyllium on the evacuation of large accumulations of sand in the large colon of adult horses. Thirty-four horses with naturally acquired, large sand accumulations (>5 cm x 15 cm) identified on abdominal radiography were randomly allocated to one of 3 treatment groups: 1) 1 g/kg bwt psyllium (n = 12); 2) 1 g/kg bwt MgSO4 (n = 10); or 3) their combination (n = 12). Treatments were administered once a day via nasogastric intubation for a total of 4 days. Lateral radiographs of the ventral abdomen were repeated on Day 4 of treatment and if the area of sand in the radiographic image was <25 cm2, the sand accumulation was considered resolved. Nine of the 12 horses treated with a combination of psyllium and MgSO4 evacuated the sand from the ventral colon within 4 days. In comparison, only 3/12 horses treated with psyllium and 2/10 horses treated with MgSO4 resolved. The authors concluded that large accumulations of sand in


the large colon of horses can be treated medically and that administering a combination of psyllium and MgSO4 via nasogastric intubation once daily for a total of 4 days was a more effective treatment than either constituent alone.


Antinociceptive effects of three escalating constant rate infusions


A. Risberg and colleagues in Norway and Switzerland investigated the antinociceptive effects of 3 escalating dexmedetomidine and lignocaine constant rate infusions in conscious horses. Intravenous (i.v.) infusions of dexmedetomidine and


lignocaine are used clinically to provide analgesia in horses. In this study using 10 Swiss Warmblood horses, the authors compared the antinociceptive effects, plasma concentrations and sedative effects of 2, 4 and 6 μg/kg bwt/h dexmedetomidine i.v., with a bolus of 0.96 μg/kg bwt preceding each continuous rate infusion (CRI), and 20, 40 and 60 μg/kg bwt/min lignocaine i.v., with a bolus of 550 μg/kg bwt preceding each CRI. Dexmedetomidine increased nociceptive threshold to


single and repeated stimulation for all CRIs, except at 2 μg/kg bwt/h, where no increase in single stimulation nociceptive threshold was observed. It also increased nociceptive tolerance to single and repeated stimulation at all CRIs. There was large individual variability in dexmedetomidine plasma concentrations and levels of sedation; the median plasma concentration providing antinociceptive effects to all recorded parameters was 0.15 ng/ml. Lignocaine increased


nociceptive threshold and tolerance to single and repeated stimulation at CRIs of 40 and 60 μg/kg bwt/min, corresponding to plasma lignocaine concentrations >600 ng/ml. Only nociceptive tolerance to repeated stimulation increased at 20 μg/kg bwt/min lignocaine. Lignocaine at 40 μg/kg bwt/min and dexmedetomidine at 4 μg/kg bwt/h were the lowest CRIs resulting in consistent antinociception. Lignocaine did not induce significant sedation.


Movement symmetry during lungeing


In this study by Thilo Pfau and colleagues in the UK, Denmark and Sweden, the difference in movement symmetry in lunged horses on different surfaces was assessed using quantitative gait analysis. Twenty-three horses, deemed sound according to their


owners were used in the study. Lameness assessment included trotting in hand on a straight line and lungeing on a 10mcircle on both reins on both hard and soft surfaces. Fourteen horses were assessed as having a forelimb lameness, with both surface and rein having an effect on movement symmetry in these horses, with asymmetry of head movement most marked when the lame limb was on the outside of the circle. In the 9 horses assessed as moving symmetrically, there was no effect of surface or rein on head or pelvic movement symmetry. Within both groups variation of movement symmetry was noted, emphasising the need to include lungeing assessment before classifying a horse as ‘sound’. The authors concluded that assessment of horses on a


straight line only should not be used as a sole measure of lameness. Assessment on both reins and on differing surfaces should be undertaken.


S. WRIGHT EVE Editorial Office References


Lassaline-Utter, M., Miller, C. and Wotman, K.L. (2014) Eosinophilic keratitis in 46 eyes of 27 horses in the Mid-Atlantic United States (2008-2012). Vet. Ophthalmol. 17, 311-320.


Marly, C., Bettschart-Wolfensberger, R., Nussbaumer, P., Moine, S. and Ringer, S.K. (2014) Evaluation of a romifidine constant rate infusion protocol with or without butorphanol for dentistry and ophthalmologic procedures in standing horses. Vet. Anaesth. Analg. 41, 491-497.


Martin-Flores, M., Campoy, L., Kinsley, M.A., Mohammed, H.O., Gleed, R.D. and Cheetham, J. (2014) Analgesic and gastrointestinal effects of epidural morphine in horses after laparoscopic cryptorchidectomy under general anesthesia. Vet. Anaesth. Analg. 41, 430-437.


Niinistö, K., Hewetson, M., Kaikkonen, R., Sykes, B.W. and Raekallio, M. (2014) Comparison of the effects of enteral psyllium, magnesium sulphate and their combination for removal of sand from the large colon of horses. Vet. J. 202, 608-611.


Pfau, T., Jennings, C., Mitchell, H., Olsen, E., Walker, A., Egenvall, A., Tröster, S.,Weller, R. and Rhodin, M. (2014) Lungeing on hard and soft surfaces: Movement symmetry of trotting horses considered sound by their owners. Equine Vet. J. Epub ahead of print DOI: 10.1111/evj.12374.


Risberg, A., Spadavecchia, C., Ranheim, B., Krontveit, R. and Haga, H.A. (2014) Antinociceptive effects of three escalating dexmedetomidine and lignocaine constant rate infusions in conscious horses. Vet. J. 202, 489-497.


Weese, J.S., Holcombe, S.J., Embertson, R.M., Kurtz, K.A., Roessner, H.A., Jalali, M. and Wismer, S.E. (2014) Changes in the faecal microbiota of mares precede the development of post partum colic. Equine Vet. J. Epub ahead of print DOI: 10.1111/evj.12361.


© 2015 EVJ Ltd


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88