AGRICULTURAL RESEARCH COMMUNICATION CENTRE www.arccjournals.com/www.ijaronline.in *Corresponding author’s e-mail: farooquiase@gmail.com 1 Division of Animal Genetics and Breeding, ICAR Indian Veterinary Research Institue, Izatnagar, Bareilly, Uttar Pradesh, India. Indian J. Anim. Res., 52(9) 2018: 1271-1280 Print ISSN:0367-6722 / Online ISSN:0976-0555 Ultrasonographic examination of caecum and colon of normal Adult Spiti horses and Himalayan Hill mules of India Uiase Bin Farooq*, Adarsh Kumar and Rajni Chaudhary 1 Department of Surgery and Radiology, College of Veterinary and Animal Sciences, Chaudhary Sarwan Kumar Himachal Pradesh Krishi Vishvavidyalaya, Palampur-176 061, Himachal Pradesh, India. Received: 10-12-2016 Accepted: 09-03-2017 DOI: 10.18805/ijar.B-3355 ABSTRACT The objective of this study was to develop baseline topographical data of landmarks for locating and generating sonographic calliper measurements along with dynamic parameters of caecum and colon in 50 native adult healthy unsedated Spiti horses and Himalayan Hill mules of either sex. The wall thickness, contractility, character and echo-architecture of caecum and colon were recorded. Caecum was found from 15 th to 17 th inter costal space (ICS). Right dorsal colon (RDC), right ventral colon (RVC), left ventral colon (LVC) and left dorsal colon (LDC) were found from 6 th to 14 th , 9 th to 17 th , 9 th to 14 th and 6 th to 15 th ICS, respectively. Descending colon was found in the left paralumbar fossa upto tuber-coxae in both horses as well as mules. The corresponding values of horses and mules for wall thickness (in mm) was 2.1±0.05 and 1.4±0.05 for the caecum, 2.16±0.05 and 1.32±0.02 for the right dorsal colon, 2.1±0.03 and 1.32 ±0.02 for the right ventral colon, 2.12±0.03 and 1.32±0.02 for the left dorsal colon, 2.1±0.03 and 1.32±0.02 for the right dorsal colon and 2.04±0.02 for the descending colon. Prominent sacculations were observed on ventral colon and absent on dorsal colon. Detailed ultrasonographic examination of caecum and colon generated baseline data, which will be useful for management of the affections of caecum and colon. Key words: Caecum, Colon, Horse, Mule, Ultrasonography. INTRODUCTION India has second largest population of equines in world. Simultaneously, the incidences of equine abdominal emergencies are very common. There are numerous factors responsible for these abdominal emergencies and lastly it becomes a challenge for the veterinarian to diagnose the exact etiology as there are very few diagnostic techniques available which mainly include radiography and rectal examination. However, these techniques have their own limitations, hence diagnostic abdominal ultrasonography is increasingly used in veterinary practice and has an important role in decision making in equines with abdominal disorders (Freeman 2002). Sonographic assessment of abdominal organs in different equine breeds has already been described (Reef, 1998; Freeman, 2002; Hendrickson et. al., 2007; Epstein et. al., 2008; Barton, 2011), but no such study has been conducted on native breeds of India. Hence, it is envisaged to perform the detailed ultrasonographic examination of caecum and colon and to compile baseline data of Spiti horses and Himalayan hill mules. MATERIALS AND METHODS The present study was carried out on 50 clinically healthy adult native animals of either sex (25 Spiti horses and 25 Himalayan hill mules). The horses were between 8- 17 years of age and weighed between 120-165 kg, whereas mules were between 8-15 years of age and weighed between 90-110 kg. The normal equine abdomen was subjected to ultrasonographic examination for standardizing the technique and machine settings. Trans-abdominal ultrasonography was performed to scan and document images of caecum and colon, to delineate their topographical anatomy in different planes, to define their echotexture and to determine their thickness and site for placement of the transducer at various locations. Ultrasonography was carried out using Siemens Acuson X300 ultrasound system, premium edition, a grey scale B + M-mode and 4D scanners. The standing animals were restrained in a crate without any sedation and were kept for 15 minutes so that their heart rate becomes normal. All animals were fasted for 12 hours prior to ultrasonography and in some animals fasting was extended to 24 hours to determine decrease in contraction rate at different time intervals but drinking water was kept available all the time. The topographic regions of all animals were shaved and cleaned with tap water. Contact gel was applied and animals were examined using two different transducers: i) 5.3-10 MHz linear transducer with a maximum depth of field of 13 cm and ii) 2-5 MHz volumetric (4D) transducer with a maximum depth of field of 30 cm. Care was taken to record