The present study comprised of 20 colic cases out of which 14 (70%) were females and 6 (30%) were male. Females were over represented for colic in present study. Most of the animals presented with colic were in the age group range of 15 days to 15 years. Out of total 20 cases included in study, 5 (25%) were below 2 years of age and 3 (15%) were above 10 years of age. Rest 12 (70%) of the colic cases were between 2 to 10 years of age. History revealed that 15/ 20 (75%) horses were fed on wheat straw while 9/20 (45%) horses were daily fed grain more than 2 kg. Course roughage with low digestibility or particularly course fibre is associated with impaction colic
(White and Dabareiner, 1997). Only 8/20 (40%) animals were having history of regular deworming. As per previous studies the risk for colic reported is 2.2 times higher in horses which do not receive any regular deworming treatment
(Cohen et al., 1999). Previous history of colic was recorded in 5/20 (25%) horses of present study.
Cohen et al., (1995) observed that a horse is more likely to develop colic if it has previously suffered from colic. The duration of colic ranged from 6 hours to 120 hours mean±SE (74.60±7.23). Colic was found to be severe in cases with small intestine strangulation and large colon obstruction whereas it was mild to moderate in cecum and small colon impactions.
Southwood (2013) noted that duration of colic is vital for determining a diagnostic and selection of cases for medicinal or surgical treatment. The water consumption was found to be markedly decreased. Loss of defecation was found in six horses with fecoliths in small and large colon. Further three horses with large colon impaction had decreased fecal output with or without having mucous in rectum. Urination frequency had markedly decreased in all the presented cases.
The most common clinical signs observed were abdominal pain and abdominal distension. Out of the 20 horses, 60% (n=12) had moderate abdominal pain and 40% (n=8) had severe pain. The presence of abdominal distension was recorded in 80% horses (n=16). Severe abdominal distension was observed in all cases having small colon impaction, Mild to moderate distensions was observed in all cases of cecum and large colon impactions whereas abdominal distension was absent in small intestine cases. Abdominal pain and distension are the characteristics of horses in which abdominal surgery is recommended
(Dabareiner and White, 1995).
The results showed that mean heart rate and respiration rate (mean±SE) were significantly higher in non-survivors in comparison to survivors (Table 1). Similar findings were observed by
Suthers et al (2013).
Gastrointestinal tract was evaluated in all four quadrants for borborygami. Normal hypomotile and hypermotile intestinal movements were noted pre and post-operatively. In the present study it was found that survivors had normal or hypomotile intestinal borborygami while non-survivors had hypomotile or amotile intestines. If borborygmi do not return after an analgesic or other treatment, the disease should be considered more serious, possibly requiring surgery
(Reeves et al, 1991, White et al., 2005).
Nasogastric intubation was performed in 15 equines and only 2 cases had positive nasogastric reflux (8 and 9 litres respectively). According to
Southwood (2013) findings positive nasogastric reflux is considered only when the volume is more than 6 litres.
In the present study, serum lactate level (Table 2-4) (mean±SE) was found to be significantly (P=0.007) increased among non-survived (7.122±1.032) in comparison to survived (3.6±0.20) horses. Blood and peritoneal fluid Lactate were accurate indicators of the tissue perfusion which is an estimate of the cardiovascular status of the horse
(Dunkel et al., 2013).
Large colon affectation (n=8) were the primary cause of the colic, followed by small colon (n=6), cecum (n=3) and small intestine (n=3) (Fig 1). Short-term survivability was 55 per cent as (11/20) of the animal discharged from the hospital while long term survival was 50 per cent (10/20) which was 90.9 per cent (10/11) of the short term survived animals. Similar short term survival (54.5%) was also reported by
Wormstand et al., (2014). In the present study affections of the small and large colon had better survival rate in comparison to small intestine or cecum as also observed by
Morton and Blikslager (2002).
Post-operative complications
In the present study, incisional complications commonly seen were oedema, drainage and infection, while incisional herniation was observed in one equine (5%). Most common incisional complication encountered in this study was oedematous swelling around the incision line found in the 7/11 survived horses. Post-operative pyrexia was seen in 20% cases of cecum strangulation (n=1), small colon impaction (n=3). Equine with cecum strangulation had maximum extent of pyrexia (105°F), which was non-responsive to antipyretics.
Post-operative laminitis was seen in equine with cecum strangulation and in a one animal suffering with small colon impaction. In all it was seen in about 10 per cent (2/10) of the cases. Post-operative diarrhoea was seen in all small and large colon with fecolith obstruction removed by surgery, as also reported by
(Salem et al., 2016).
Thrombophlebitis was seen in 20 per cent (4/20) of the cases. Post-operative peritonitis and postoperative ileus were major life threatening complications encountered in 40% (8/20) horses of this study. Recurrent mild colic was found in five out of eleven long-term survived horses. Mild colic was seen in horses with change of feed and responded satisfactorily to analgesic (Flunixin meglumine@ 1.1 mg/kg IV) and was seen up to 2 months after surgery. Changes in feeding schedule and regular exercise helped in management of the colic.