Ponies, miniatures, and younger equids are at higher risk of fecalith obstruction compared to a general colic population

Mitja Miklavcic William R. Prichard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, CA

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Julie E. Dechant Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA

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Isabelle Kilcoyne Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA

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Abstract

OBJECTIVE

To determine breed, age, and sex predispositions for fecalith obstruction and to evaluate short-term survival and prognostic factors following surgical treatment of fecalith intestinal obstruction in equids.

ANIMALS

151 equids.

METHODS

Medical records of equids undergoing surgery for fecalith obstruction from 2000 to 2020 were reviewed. Signalment, history, presenting clinicopathological data, surgical findings, complications, and short-term survival were recorded and compared between survivors and nonsurvivors. Signalment of the fecalith population was compared to a contemporaneous colic population. Clinical factors were assessed for association with outcome.

RESULTS

64 females, 53 castrated males, and 31 intact males were included. Three equids presented twice. Miniature horses, ponies, and miniature donkeys/mules represented 48% (71/148) of fecalith population and full-sized breeds represented 52% (77/148). Miniature horses and ponies were overrepresented and equids ≤ 1 year of age were overrepresented in the fecalith population compared to the colic population. One hundred thirty-nine equids (92%) survived to discharge, 6% (9/148) were euthanized intraoperatively, and 2% (3/148) were euthanized during hospitalization. Nonsurvivors showed more severe colic signs on admission, tachycardia on admission, and hyperlipemia. Equids with postoperative colic (P = .01) and complications (P = .002) were less likely to survive.

CLINICAL RELEVANCE

Miniature horses and ponies were overrepresented compared to the colic population; however, full-sized breeds were also affected. Surgical treatment had an excellent short-term prognosis. Severe colic signs, tachycardia, hyperlipemia, postoperative colic, and surgical complications negatively affected short-term survival.

Abstract

OBJECTIVE

To determine breed, age, and sex predispositions for fecalith obstruction and to evaluate short-term survival and prognostic factors following surgical treatment of fecalith intestinal obstruction in equids.

ANIMALS

151 equids.

METHODS

Medical records of equids undergoing surgery for fecalith obstruction from 2000 to 2020 were reviewed. Signalment, history, presenting clinicopathological data, surgical findings, complications, and short-term survival were recorded and compared between survivors and nonsurvivors. Signalment of the fecalith population was compared to a contemporaneous colic population. Clinical factors were assessed for association with outcome.

RESULTS

64 females, 53 castrated males, and 31 intact males were included. Three equids presented twice. Miniature horses, ponies, and miniature donkeys/mules represented 48% (71/148) of fecalith population and full-sized breeds represented 52% (77/148). Miniature horses and ponies were overrepresented and equids ≤ 1 year of age were overrepresented in the fecalith population compared to the colic population. One hundred thirty-nine equids (92%) survived to discharge, 6% (9/148) were euthanized intraoperatively, and 2% (3/148) were euthanized during hospitalization. Nonsurvivors showed more severe colic signs on admission, tachycardia on admission, and hyperlipemia. Equids with postoperative colic (P = .01) and complications (P = .002) were less likely to survive.

CLINICAL RELEVANCE

Miniature horses and ponies were overrepresented compared to the colic population; however, full-sized breeds were also affected. Surgical treatment had an excellent short-term prognosis. Severe colic signs, tachycardia, hyperlipemia, postoperative colic, and surgical complications negatively affected short-term survival.

Introduction

A fecalith is a firm, ovoid accumulation of ingesta or matted plant material (phytoconglobate) that can cause intraluminal obstruction of the ascending, transverse, or descending colon in equids.1 Fecalith obstruction often requires surgical management due to difficulty in softening the obstruction with medical treatments, severity of intestinal distension, and pressure necrosis associated with these focal obstructions. In the current literature, a significant number of studies report that fecalith obstruction is predominantly found in miniature breeds, supporting the empirical observation that these breeds are overrepresented.24 Furthermore, ponies, young horses (≤ 1 year old), and older horses with poor dentition are described as being predisposed to fecaliths.2,5,6

Both medical and surgical treatment for fecalith intestinal obstructions have been described in the literature.24,7 Medical management can consist of maintaining hydration, stimulation of gastrointestinal motility, softening of the impaction via administration of osmotic laxatives or lubricants, and control of pain.8 Surgical intervention is necessary when there is a lack of response to medical treatment, persistent pain, or severe abdominal distension. Other indications for surgical intervention would be changes in peritoneal fluid parameters indicating intestinal compromise.9

Reported short- and long-term survival for surgical management of horses affected by fecaliths vary in the literature. Short-term survival of these cases appears to be similar to previously reported rates following exploratory celiotomy for management of displacements and simple obstructions (excluding fecalith) of the large and small colon (77.8% to 100%).4,1016 Specifically looking at obstruction by a fecalith, 1 study10 reported short-term survival of 4 of 5 affected horses and another study4 documented survival to discharge in 38 of 38 horses. Few studies have documented long-term survival of horses with fecaliths, with 2 studies reporting 5 of 7 and 32 of 38 surviving long-term.3,4

Clinical presentation, findings, and surgical outcome of fecalith obstruction have not been described in a large population. Although it has been extensively reported that miniature horses are predisposed to fecalith formation, it had been our clinical impression that fecaliths can occur in a multitude of other breeds. We suspected that dental disease could lead to inadequate mastication and, in combination with poor quality roughage, contribute to increased susceptibility to fecalith obstruction in aged equids.

The objective of this study was to determine the case characteristics associated with fecalith obstruction in equids. Our hypotheses were that miniature horses and ponies, young horses (≤ 1 year old), and aged equids (> 20 years old) would be predisposed to fecalith obstruction compared to a general colic population. A secondary hypothesis was that survival following surgery for fecalith obstruction would be excellent, with equids presenting with more severe systemic derangements having a poorer prognosis.

Methods

Study populations

Medical records of equids presented to the William R. Pritchard Veterinary Medical Teaching Hospital for colic between January 2000 and December 2020 were reviewed. Inclusion criteria were equids of any age that presented primarily for colic signs and were subsequently diagnosed with a fecalith obstruction during exploratory celiotomy (fecalith group). A fecalith was defined as a focal, ovoid obstruction of the large, transverse, or small colon by firm accumulation of ingesta that could be manually deformed or disrupted when hydrated and manipulated. Surgical management was pursued for cases in which pain could not be controlled with medical management and cases with severe intestinal gas accumulation causing cardiorespiratory compromise. Equids suffering from an obstructive fecalith euthanized without surgical treatment and those treated exclusively by medical management were excluded from this study. Intestinal obstructions by mineral accumulations and regionally extensive colon impactions were excluded from the fecalith definition. To establish a comparison group, all other colic admissions during this time period were categorized as the colic group.

Information obtained from medical records

Signalment (age, breed, and sex) were recorded for all colic cases (fecalith group and colic group) admitted during the study period. Breed and sex were collected on a per-horse basis, whereas age was collected by visit for those equids with multiple visits for colic. Data collected for the fecalith group also included historical details, diet, duration and severity of colic signs, admission physical examination findings and clinicopathological data, surgical findings, postoperative complications, and outcome. Historical details included previous colic or colic surgery and previous history pertaining to the incidence of fecalith formation in the herd. Duration of colic signs was defined as acute (< 12 hours), subacute (12 to 24 hours), and prolonged colic (> 24 hours). Severity of colic signs was defined as mild (standing quietly), moderate (intermittent pawing, looking at flanks, kicking at belly), severe (actively trying to lay down and roll), or obtunded (quiet, depressed, having muscle fasciculations). Initial physical examination parameters (body temperature, heart rate, and respiratory rate) were recorded. Presenting clinicopathological data (PCV, total protein [TP], lactate, total nucleated cell count [TNCC], triglycerides, creatinine) as well as peritoneal fluid parameters (TNCC, TP, lactate) were documented. The type of celiotomy and anatomical location of the fecalith at surgery were recorded. Surgical procedures were recorded, including whether an enterotomy was performed and location, need for resection, or whether the fecalith was manually broken down transmurally. Postoperative complications for each case were recorded.

Tachycardia was defined as heart rate > 52 beats/min, tachypnea as respiratory rate > 24 breaths/min, and elevated rectal temperature (pyrexia) as > 38.6 °C (101.5 °F). Hypertriglyceridemia was defined as serum triglycerides > 41 mg/dL. Postoperative reflux was defined as > 2 L in full-sized horses, > 1 L in ponies, and > 0.5 L in miniature horses of net reflux following nasogastric intubation at any single time point. Postoperative fever was defined as body temperature > 38.6 °C (101.5 °F) for > 12 hours at any time during postoperative hospitalization. Postoperative diarrhea was defined as unformed (looser than cowpie) feces persisting for more than the first 24 hours after surgery. Postoperative colic was defined as signs of abdominal pain or colic at any time after surgery. Septic postoperative peritonitis was defined on the basis of peritoneal fluid values, cytological evidence of intracellular microorganisms, positive culture of peritoneal fluid, or necropsy findings. Incisional infection was defined as presence of discharge from the incision and subsequent bacterial growth on the culture. Short-term survival was defined as survival to discharge from the hospital. If horses were euthanized, results of any subsequent necropsy examination were recorded.

Statistical analysis

Data were evaluated for normality using Q-Q plots and the Shapiro-Wilk test. Continuous data were summarized as mean and SD, whereas categorical data were summarized as counts and percentages. Signalment for the fecalith group was compared to the colic population (colic group) during the same time frame. Breed and sex were compared using a χ2 analysis on a per-horse basis. Age was analyzed per visit using a Student t test to compare mean ages between the fecalith group and the colic group and a χ2 analysis by converting into categorical variables (≤ 1 year, > 1 to 3 years, > 3 to 5 years, > 5 to 10 years, > 10 to 15 years, > 15 to 20 years, > 20 to 25 years, > 25 years). A Bonferroni adjustment was made for multiple comparisons, when applicable. Colic duration, colic severity, and physical examination and clinicopathological findings were compared between fecalith locations (large colon vs small colon) using χ2 and Student t tests for categorical and continuous variables, respectively. Signalment, colic duration, colic severity, physical examination findings, clinicopathological findings, location of fecalith obstruction, and postoperative complications were compared between survivors and nonsurvivors using χ2 and Mann-Whitney U tests for categorical and continuous variables, respectively. Significance was set as P < .05.

Results

Study population

A total of 148 equids were included in the fecalith group, in which 151 surgical treatments for fecalith obstruction were performed. Two ponies (1 castrated male and 1 female) and 1 female miniature horse underwent surgical intervention twice for fecalithiasis. There were 64 females, 53 castrated males, and 31 intact males. Mean age for the fecalith group was 10.9 ± 9.4 years. Breeds included miniature horses (55/148 [37%]), Quarter Horse/Paint (34/148 [23%]), pony breeds (13/148 [9%]), Arabian (7/148 [5%]), Appaloosa (3/148 [2%]), Morgan (3/148 [2%]), donkey/mule (3/148 [2%]), mixed breed (3/148 [2%]), Andalusian (3/148 [2%]), Warmblood (2/148 [1%]), Friesian (2/148 [1%]), Mustang (2/148 [1%]), Standardbred (2/148 [1%]), Tennessee Walking Horse (2/148 [1%]), Hackney (2/148 [1%]), Peruvian Paso (2/148 [1%]) and 1 each (0.7%) of Azteca, Connemara, Clydesdale, Gypsy Vanner, Haflinger, National Show Horse, Polo Pony, Rocky Mountain Horse, Saddlebred, and Thoroughbred.

Comparison between colic and fecalith group

A total of 7,506 colic presentations in 6,706 equids were included in the colic comparison group. Signalment comparisons between the fecalith group and colic group are presented in Table 1. Sex distribution between females, castrated males, and intact males were significantly different between the fecalith and colic groups (P = .0001); however, this difference was not significant when compared between females and males (P = 1.00). Breed distribution was significantly different between the fecalith and colic groups, with miniature horses and pony breeds (P < .0001) and Andalusians (P < .05) being significantly overrepresented and Arabians, Thoroughbreds, and Warmbloods being significantly underrepresented (P ≤ .04) in the fecalith group compared to the colic group. Mean age of the fecalith group was 10.9 ± 9.4 years compared to 12.4 ± 7.5 years in the colic group (P = .07). When compared by age groups, equids aged ≤ 1 year were significantly overrepresented (P < .001) and equids aged 5 to 10 years were significantly underrepresented in the fecalith group compared to the colic group (P < .05).

Table 1

Comparison of sex, breed, and age groups between equids undergoing surgical treatment of fecalith obstruction between 2001 and 2020 compared to a contemporaneous colic population. Sex and breed are compared on a per-horse basis, whereas age groups are compared on a per-visit basis. Individual pairwise comparisons were adjusted using a Bonferroni adjustment.

Colic Fecalith Overall comparison Individual comparisons
Breed (colic, n = 6,706; fecalith, n = 148)
 Andalusian 11 (0.2%) 3 (2.0%) P < .0001 P < .05; overrepresented
 Appaloosa 118 (1.8%) 3 (2.0%) NSD
 Arabian 882 (13.2%) 7 (4.7%) P = .04; underrepresented
 Draft 118 (1.8%) 2 (1.4%) NSD
 Friesian 90 (1.3%) 2 (1.4%) NSD
 Miniature horse 131 (1.9%) 55 (37.2%) P < .001; overrepresented
 Mixed breed 355 (5.3%) 3 (2.0%) NSD
 Morgan 181 (2.7%) 3 (2.0%) NSD
 Donkey/mule 51 (0.8%) 3 (2.0%) NSD
 Mustang 66 (1.0%) 2 (1.4%) NSD
 Other 272 (4.1%) 11 (7.4%) NSD
 Pony breeds 156 (2.3%) 13 (8.8%) P < .001; overrepresented
 Quarter horse 2,152 (32.1%) 34 (23.0%) NSD
 Standardbred 65 (1.0%) 2 (1.4%) NSD
 Thoroughbred 1,043 (15.6%) 1 (0.7%) P < .001; underrepresented
 Tennessee Walking Horse 89 (1.3%) 2 (1.4%) NSD
 Warmblood 926 (13.8%) 2 (1.4%) P < .001; underrepresented
Sex (colic, n = 6,706; fecalith, n = 148)
 Female 2,910 (43.4%) 64 (43.2%) P = .0002 NSD
 Gelding 3,085 (46.0%) 53 (35.8%) P = .04; underrepresented
 Intact male 711 (10.6%) 31 (21.0%) P = .0006; overrepresented
Age (colic, n = 7,506; fecalith, n = 151)
 ≤ 1 y 534 (7.1%) 38 (25.2%) P < .0001 P < .001; overrepresented
 > 1–3 y 344 (4.6%) 13 (8.6%) NSD
 > 3–5 y 558 (7.4%) 7 (4.6%) NSD
 > 5–10 y 1,643 (21.9%) 19 (12.6%) P < .05; underrepresented
 > 10–15 y 1,834 (24.4%) 25 (16.6%) NSD
 > 15–20 y 1,324 (17.6%) 19 (12.6%) NSD
 > 20–25 y 849 (11.3%) 17 (11.3%) NSD
 > 25 y 420 (5.6%) 13 (8.6%) NSD

NSD = Not significantly different.

History and presentation

Dietary information was available for 93 cases, with the distribution of forage types as follows: alfalfa hay (33/93 [35%]), grass hay (16/93 [17%]), oat hay (2/93 [2%]), combinations of grass and alfalfa hay (24/93 [26%]), alfalfa and oat hay (2/93 [2%]), grass and oat hay (2/93 [2%]), and alfalfa and rye hay (1/93 [1%]). Furthermore, 25 equids had access to green pasture, with 9 exclusively consuming green grass. Two neonatal equids were nursing only. In addition to forage, pelleted feed was fed to 31 equids.

Duration of colic signs prior to presentation was recorded in 145 records. Sixty-five of 145 (44%) presentations were acute (< 12 hours), 40 (27%) presentations were subacute (12 to 24 hours), and 40 (27%) presentations were prolonged (> 24 hours). Twenty-eight equids had a history of previous colic. Seventeen owners had equids with a previous diagnosis of fecalith formation.

Severity of colic signs could be characterized in 125 visit records. Seven of 125 (6%) presentations were characterized as having mild colic signs, 18 (14%) presentations were characterized as having moderate colic signs, 84 (67%) presentations were characterized as having severe colic signs, and 16 (13%) presentations were characterized as obtunded. Twenty-one equids were found to have reflux at presentation, whereas 82 equids did not. Reflux status was not recorded in 48 visit records. Clinicopathological findings are presented in Table 2. As a group, equids with fecalith obstruction presented with a moderately elevated heart rate (mean ± SD, 67 ± 21 beats/min), elevated respiratory rate (29 ± 13 breaths/min), and normal rectal temperature 37.9 ± 0.6 °C (100.3 ± 1.1 °F). Hematocrit (37.3 ± 7.1%) and TP (7.0 ± 1.0 g/dL) were normal to elevated with hyperlactatemia (3.4 ± 3.4 mmol/L) and hypertriglyceridemia (324 ± 711 mg/dL). Peritoneal fluid TNCC were elevated (7,610 ± 19,800 cells/μL) with an elevated TP (2.5 ± 0.9 g/dL).

Table 2

Means and SDs for admission clinicopathological parameters equids with fecaliths and associations with outcome.

Parameter All (n = 151) Survivors (n = 139) Nonsurvivors (n = 12) Significance
Age (y) n = 151 11.0 ± 9.4 n = 139 10.9 ± 9.3 n = 12 11.2 ± 10.9 NSD
Temperature (°F) n = 139 100.3 ± 1.1 (37.9 ± 0.6 °C) n = 127 100.3 ± 1.1 (37.9 ± 0.6 °C) n = 12 99.8 ± 1.2 (37.7 ± 0.6 °C) NSD
Heart rate n = 149 67 ± 21 n = 137 66 ± 21 n = 12 80 ± 23 P = .038
Respiratory rate n = 146 29 ± 13 n = 135 29 ± 13 n = 11 31 ± 11 NSD
PCV (%) n = 146 37.3 ± 7.1 n = 134 37.1 ± 7.1 n = 12 39.6 ± 7.4 NSD
Total protein (g/dL) n = 147 7.0 ± 1.0 n = 136 7.0 ± 1.0 n = 11 6.8 ± 1.0 NSD
Blood lactate (mmol/L) n = 111 3.4 ± 3.4 n = 101 3.5 ± 3.5 n = 10 3.3 ± 2.1 NSD
Blood TNCC (cells/µL) n = 137 8,160 ± 4,110 n = 126 8,320 ± 4,150 n = 11 6,400 ± 3,210 NSD
Triglycerides (mg/dL) n = 81 324 ± 711 n = 77 236 ± 304 n = 4 2,032 ± 2,654 P = .007
Creatinine (mg/dL) n = 128 1.3 ± 0.5 n = 118 1.4 ± 0.5 n = 10 1.1 ± 0.3 NSD
Peritoneal TNCC (cells/µL) n = 97 7,610 ± 19,800 n = 90 6,740 ± 19,400 n = 7 18,910 ± 22,960 NSD
Peritoneal TP (g/dL) n = 100 2.5 ± 0.9 n = 94 2.5 ± 0.9 n = 6 3.2 ± 1.4 NSD
Peritoneal lactate (mmol/L) n = 67 3.8 ± 4.1 n = 63 3.6 ± 4.1 n = 4 5.6 ± 3.4 NSD

NSD = Not significantly different. TNCC = Total nucleated cell count. TP = Total protein.

Fecalith location was determined on the basis of surgical findings (Table 3). There was no difference in clinical presentation between fecalith obstruction of the large colon versus the small colon (which included transverse colon) for breed, sex, colic duration, severity of colic signs, temperature, respiratory rate, reflux, PCV, TP, lactate, TNCC, triglycerides, creatinine, peritoneal TP, and peritoneal lactate. Age (13.3 ± 9.2 years vs 9.2 ± 9.3 years), heart rate (63 ± 20 beats/min vs 70 ± 22 beats/min), and peritoneal TNCC (3,070 ± 5,140 cells/μL vs 11,630 ± 26,120 cells/μL) were significantly different (P < .04) between large colon fecalith obstructions and small colon fecalith obstructions, respectively.

Table 3

Location of fecalith obstruction and the surgical procedures used to resolve the obstruction.

Location of obstruction Location of enterotomy Resection and anastomosis Total
Pelvic flexure Small colon Pelvic flexure and small colon None Not recorded
Large colon 52* 0 0 0 5 1 58
Transverse colon^ 2 0 0 0 0 0 2
Small colon 16& 6 30$ 14& 10 1 77
Large/transverse and small colon# 3& 0 2 0 2 0 7
Not recorded 4 0 0 0 3 0 7
Total 77 6 32 14 20 2 151

*One enterotomy was positioned over a right dorsal colon fecalith.

^One case with transverse colon fecalith; 1 case with left dorsal colon and transverse colon fecaliths.

&Twenty-nine small colon fecaliths resolved with manual massage, 2 small colon fecaliths resolved with enema per rectum, and 2 small colon fecalith resolution not recorded.

$Two small colon enterotomies recorded in 1 surgery.

#Five cases with large colon and small colon fecaliths; 2 cases with transverse colon and small colon fecaliths.

Surgical intervention

Ventral midline celiotomy under general anesthesia was utilized as the surgical approach in all cases. Location of fecaliths and type of surgical procedures to resolve them are summarized in Table 3. Fecaliths were found in the large colon (n = 58), transverse colon (2), small colon (77), or both small and large/transverse colon (7). Location was not recorded in 7 cases. To resolve the fecalith obstruction, a pelvic flexure enterotomy (n = 77), small colon enterotomy (6), right dorsal colon enterotomy (1), or combination of pelvic flexure and small colon enterotomy (32) was performed. Small colon fecaliths were disrupted manually without enterotomy in 29 cases and were resolved with assistance of an enema in 2 cases. The type of intervention was not reported in 20 cases. In 2 cases, pressure necrosis as a result of the fecalith obstruction necessitated resection and anastomosis of the affected segment. In 1 case, a 20-cm-long segment adjacent to the pelvic flexure was removed and an end-to-end colon resection was performed. In the other case, a fecalith-size segment of small colon was resected. Both anastomoses were sutured in 2 layers using 2-0 polydioxanone (full-thickness simple continuous pattern oversewn with a Cushing pattern). A pelvic flexure enterotomy was performed to remove adjacent fecaliths located in the large colon or to allow ingress of water for hydrating and softening fecaliths located in aboral segments of intestine. All enterotomies were performed on the antimesenteric band and were closed in 2 layers using 2-0 polydioxanone (full-thickness simple continuous pattern oversewn with a Cushing pattern).

During exploratory celiotomy, concurrent surgical findings noted included right dorsal displacement (n = 6), right dorsal displacement with moderate sand accumulation of the large colon (1), 180° large colon volvulus (3), 360° large colon volvulus with severe sand accumulation of the colon (1), sand accumulation of the large colon (4), incidental (nonobstructive) enterolithiasis (4), sand impaction and enterolith (1), incidental adhesions (3), gastric impaction (1), and cecal distension with fluid necessitating typhlotomy (1). Nine animals were euthanized during surgery, of which 7 had intestinal rupture and 2 had severe colonic wall necrosis at the site of obstruction.

Postoperative complications

Ten (7%) equids developed postoperative diarrhea, with Clostridium difficile being isolated from 2 cases. Postoperative colic occurred in 9 cases, 3 of which required repeat celiotomy during the postoperative hospitalization period. Of these 3 cases, 1 was diagnosed at repeat celiotomy with a large colon impaction, 1 had developed a cecal impaction, and the third developed clinically significant adhesions. The horse that had undergone repeat celiotomy in the immediate postoperative period for the large colon impaction developed adhesions and secondary small intestinal strangulation 5 months later and was euthanized.

Five equids developed septic peritonitis, which was diagnosed at day 5 in 3 cases and day 4 in 1 case postoperatively via abdominocentesis. One equid was subsequently diagnosed with septic peritonitis at necropsy. Peritonitis was treated with systemic antimicrobials on the basis of culture and sensitivity of the peritoneal fluid, when available, and supportive care. Three equids with septic peritonitis were euthanized due to persistent colic signs and failure to respond to treatment. Two of these cases underwent necropsy, which revealed focal colonic necrosis (pelvic flexure) in 1 case. Suppurative colitis and reimpaction of the small colon at the previous site of obstruction was noted in the second case. The third case had undergone a small colon resection and anastomosis, and leakage from the anastomosis site was suspected due to evidence of septic peritonitis on the basis of the clinicopathological parameters in the peritoneal fluid.

Three cases developed or had persistent hyperlipidemia (675 to 5,981 mg/dL) in the postoperative period. This was treated with continuous IV administration of dextrose (0.25 to 2 mg/kg/min) and insulin (0.015 to 0.2 IU/kg/h) combined with intragastric administration of a complete enteral supplement in 1 case. All cases responded well to supported care and treatment and were subsequently discharged from the hospital.

Fifteen equids developed postoperative fever. Other postoperative complications included pneumonia, postoperative reflux, and incisional infection, all occurring in 2 cases. Acute kidney injury, laminitis, enterocolitis, cecal impaction, abdominal bleeding, and adhesions each occurred in 1 equid. One late pregnant female developed incisional drainage prior to abdominal wall dehiscence, which was repaired using stainless steel wire after terminating the pregnancy. This horse ultimately did well and was discharged from the hospital.

Survival to discharge

One hundred thirty-nine (92%) equids survived to discharge, 9 (6%) were euthanized during surgery, and 3 (2%) were euthanized during hospitalization. Seven equids were euthanized during surgery due to intestinal rupture, and 2 equids were euthanized due to necrotic colonic wall at the obstruction site. All 3 equids euthanized in the postoperative period were those that developed septic peritonitis.

Comparisons between survivors and nonsurvivors

Duration of colic and severity of colic signs were compared between survivors and nonsurvivors and were not significantly associated with survival (Table 4). Higher heart rate on admission (P = .04) and hypertriglyceridemia on admission (P = .007) were associated with nonsurvival (Table 2), whereas other clinicopathological parameters were not associated with outcome.

Table 4

Comparison of preoperative and postoperative findings between survivors and nonsurvivors.

Survivors Nonsurvivors P Value
Duration of colic n = 134 (missing n = 5) n = 11 (missing n = 1)
 Acute (< 12 h) 61 (45.5%) 4 (36.4%) P = .38
 Subacute (12–24 h) 38 (28.4%) 2 (18.2%)
 Prolonged (> 24 h) 35 (26.1%) 5 (45.5%)
Severity of colic n = 115 (missing n = 24) n = 10 (missing n = 2)
 Mild 7 (6.1%) 0 P = .06
 Moderate 17 (15.8%) 1 (10%)
 Severe 79 (68.7%) 5 (50%)
 Obtunded 12 (10.4%) 4 (40%)
Postoperative fever n = 139 n = 3*
 Yes 15 (10.9%) 0 P = 1.00
 No 124 (89.1%) 3
Postoperative diarrhea n = 139 n = 3*
 Yes 10 (7.2%) 0 P = 1.00
 No 129 (92.8%) 3
Postoperative colic n = 139 n = 3*
 Yes 7 (10.9%) 2 P = .01
 No 132 (89.1%) 1
Other postoperative complications^ n = 139 n = 3*
  Yes 15 (10.8%) 0 P = .002
  No 124 (89.2%) 3

*Of the 12 nonsurvivors, 9 equids were euthanized in surgery. Three equids were euthanized as a consequence of postoperative complications.

^Postoperative complications tallied as other complications include peritonitis (2 survivors, 3 nonsurvivors), hypertriglyceridemia (1 survivor, 1 nonsurvivor), pneumonia (2 survivors), postoperative reflux (2 survivors), incision infection (2 survivors), acute kidney injury (1 survivor), abdominal bleeding (1 survivor), adhesion (1 survivor), incision dehiscence (1 survivor), laminitis (1 survivor), cecal impaction (1 survivor), and enterocolitis (1 nonsurvivor). Some individuals had multiple complications.

Fifty-six out of 58 cases with fecalith obstruction involving the large colon survived to discharge compared to 70 of 79 cases involving the small or transverse colon. All 7 horses with fecaliths in the small and large colon and 6 of 7 horses with unrecorded location survived. Location of fecalith obstruction (small vs large colon) was not associated with outcome (P = .12).

Postoperative fever and postoperative diarrhea were not associated with outcome (Table 4). Equids with postoperative colic and other postoperative complications were significantly less likely to survive (P = .01 and .002, respectively).

Discussion

The results of this study supported our hypothesis that miniature horses and pony breeds would be overrepresented in the fecalith obstruction group, as previously reported in the literature.24 Interestingly, many other breed types were also included (54%), suggesting that full-sized breeds are also at risk. Although Andalusians were found to be overrepresented in this study, we do not believe this is related to a propensity for developing fecaliths but rather a spurious finding caused by small numbers of this breed in our general hospital population. The underrepresentation of Arabians, Thoroughbreds, and Warmbloods in the fecalith group was likely caused by predispositions of these breeds to other causes of colic in the colic population, such as strangulating lipomas, epiploic foramen entrapments, and large colon displacements, respectively.1719 This study also confirmed our hypothesis that young equids (≤ 1 year old) were overrepresented in the fecalith obstruction group. However, contrary to our hypothesis, there was no significant difference in the presentation of aged equids between the colic and fecalith obstruction groups. Intact males were overrepresented whereas castrated males were underrepresented in the fecalith group compared to the colic group. However, when comparing males (intact and castrated) and females, there was no difference between the fecalith and colic groups. We believe that the overrepresentation of intact males was an artifact of the overrepresentation of equids ≤ 1 year of age in the fecalith group, as most male horses are not gelded until they are > 1 year of age.20

Although some presentations of fecalith intestinal obstructions can respond to medical treatment and medical treatment was attempted in some of the equids included in this study, it is our impression that many of these cases require surgical intervention. It is important to note that the majority of cases (> 75%) in this study population presented with severe colic or signs of being obtunded. Additionally, mean heart rate and respiratory rate were elevated on presentation, which could also be seen as a marker of pain. In our study, mean peritoneal fluid parameters (TNCC and TP) were slightly above the reference range; however, the degree to which these values contributed to clinical decision-making is difficult to ascertain given the retrospective nature of the study.

Twelve included cases had evidence of concurrent lesions noted at surgery, of which > 50% involved some type of displacement. It is reasonable to assume that gas distension due to partial or complete obstruction by a fecalith may result in a concurrent displacement or other gastrointestinal lesion. Evaluation of radiographs for the presence of excessive gas accumulation, in addition to abnormal rectal findings in sufficiently large patients, may help increase the index of suspicion of a displacement or even complete obstruction in painful horses and expediate taking these horses to surgery.

Standing flank laparotomy has been reported as an alternative to the more traditional ventral midline approach to resolve simple intestinal obstruction, particularly in cases involving the small colon.21 Standing flank laparotomy was not utilized in this case series, because the severe gas distension that often accompanies cases of fecalith obstruction makes the flank approach more challenging. Most importantly, ventral midline celiotomy allows for a more thorough abdominal exploration, which is helpful if the definitive diagnosis and location of a fecalith obstruction is not known before surgical intervention and when concurrent secondary diagnoses may be present. It is important for the surgeon to weigh the advantages and disadvantages of each approach when making decisions for an individual patient.

Surgical treatment of fecalith obstruction carries an excellent short-term prognosis. Comparable studies reported short-term survival to discharge of 78% to 100% after colic surgery for large intestinal obstruction and 80% to 100% for fecalith obstruction.4,1016 The location and focal nature of intestinal obstruction caused by fecaliths resemble the type of intestinal obstruction caused by enteroliths. In 1 study22 of enterolithiasis in 236 horses, obstruction due to an enterolith was reported in the large colon in 59% of cases and the small colon in 41% of cases. In that same study, nonsurvival was associated with obstruction of the small colon.22 In this study, there were few clinical characteristics and findings that were significantly different between fecalith obstruction of the small colon or the large colon, and the clinical utility of these differences may be low. Abdominal TNCC was significantly higher with small colon fecalith obstructions than those in the large colon, which suggests a higher degree of intestinal compromise; however, a significant association between fecalith location and outcome was not detected in this study.

Severe colic signs, high heart rate, and hypertriglyceridemia likely represent more advanced disease conditions at presentation, which may relate to increased severity of intestinal compromise, systemic hypoperfusion, and metabolic derangements. Tachycardia has been associated with survival in other studies, but no association was found in surgically treated colic cases.23,24 Interestingly, other vital parameters as well as PCV, TP, and blood lactate were not associated with survival in our study. Several other studies have found significant associations between survival in colic cases and lactate and/or PCV.2527 In the aforementioned studies, different types of colic were studied, and so direct comparison to our results is not applicable. Hypertriglyceridemia has been previously associated with nonsurvival in colic patients, being linked to the underlying pathology (endotoxemia, enteritis) or an indicator of increased organ damage.28,29 Postoperative complications in general were associated with nonsurvival after surgery, although numbers were limited as most nonsurvivors were euthanized in surgery. Five cases did develop peritonitis in the postoperative period. It has been reported that peritonitis after abdominal surgery results in higher mortality (56%) compared to peritonitis without gastrointestinal rupture or abdominal surgery (43%).30 Peritonitis after colic surgery often indicates that there is leakage of intestinal contents from enterotomies, anastomosis, or devitalized intestine. In our study, septic peritonitis was associated with focal necrosis at the obstruction site, reimpaction at the enterotomy site, and presumed leakage from a small colon resection and anastomosis site. This was not surprising given the degree of intestinal wall ischemia that can be found where a complete obstruction has occurred. Typically, where focal areas of necrotic colon wall were noted at surgery, these areas were oversewn using an inverting suture pattern in an attempt to prevent leakage and reestablish colon wall integrity. Additionally, all cases underwent extensive peritoneal lavage at the end of surgery. There are specific factors in small colon surgery that can lead to an increased risk for stricture formation, dehiscence, peritonitis, and reimpaction, including higher concentration of intraluminal bacteria, high concentration of collagenase, segmental blood supply compared to the large colon, and the mechanical stress placed on the enterotomy site during passage of firm fecal balls. Good surgical technique is crucial to successful small colon surgery with focus on meticulous asepsis, atraumatic tissue handling, draping to isolate open bowel, and efficient closure to maintain maximal luminal diameter, as well as peritoneal lavage, antimicrobial use, and slow refeeding with pelleted feed.31,32 The prevalence of postoperative septic peritonitis in this study was comparable to Pierce et al,22 who reported on complications of surgical management of enteroliths. This emphasizes that any kind of obstruction can cause significant intestinal injury, and for cases in which focal obstruction is suspected and the case is not responding to medical management, surgical intervention should be instituted as early as possible to prevent this degree of intestinal injury and subsequent complications.

Further research is warranted to determine etiologic factors for fecalith development. It is our impression that dental care in miniature horses is often overlooked, which could play a role of fecalith development in these breeds. However, it was interesting to note that there was not a significant difference in prevalence with regard to aged horses, which have a high prevalence of dental disease compared to younger horses.33 An argument against the role of dentition as a risk factor for fecalith formation was proposed by Gunnarsdottir et al.34 This study reported that horses with large colon impactions did not have evidence of worse dentition when compared with a control population, indicating that other variables may also play a role. It is likely a multifactorial issue and other variables like geographical location, feed type, and quality and water supply may all be factors to consider. When considering younger equids (< 1 year of age) that are more predisposed to fecalith formation compared to the total colic population, it has been suggested that young horses have more indiscriminate eating habits that could predispose them to fecalith formation.5 Another hypothesis is that the inability to masticate or digest forage adequately may play a role.35 Further research is needed to identify the other risk factors in young horses such as developing dentition, altered motility due to parasite infestation, and gastrointestinal microbiota change at weaning.

Limitations of the study were the retrospective design and incomplete recording of clinical variables and potential risk factors (diet and dental history). Bias associated with case management and clinician preference could not be controlled. The majority of cases were discharged from the hospital in the first 5 to 7 days after surgery. Long-term complications (eg, incisional infection, adhesions) that could have impacted the complication rate and survival rate may have been missed, and this should be considered an additional limitation of the study. Furthermore, statistical power was limited due to the small number of nonsurvivors.

In conclusion, while miniature horses and ponies are predisposed to these obstructions, full-sized horse breeds may also be affected. Surgical management of fecalith obstruction is associated with an excellent prognosis for short-term survival. Further research is necessary to identify etiological factors associated with these types of intestinal obstructions.

Acknowledgments

None reported.

Disclosures

The authors have nothing to disclose. No AI-assisted technologies were used in the generation of this manuscript.

Funding

The authors have nothing to disclose.

References

  • 1.

    Gay CC, Speirs VC, Christie BA, Smyth B, Parry B. Foreign body obstruction of the small colon in six horses. Equine Vet J. 1979;11(1):60-63. doi:10.1111/j.2042-3306.1979.tb01302.x

    • Search Google Scholar
    • Export Citation
  • 2.

    McClure JT, Kobluk C, Voller K, Geor RJ, Ames TR, Sivula N. Fecalith impaction in four miniature foals. J Am Vet Med Assoc. 1992;200(2):205-207. doi:10.2460/javma.1992.200.02.205

    • Search Google Scholar
    • Export Citation
  • 3.

    Hughes KJ, Dowling BA, Matthews SA, Dart AJ. Results of surgical treatment of colic in miniature breed horses: 11 cases. Aust Vet J. 2003;81(5):260-264. doi:10.1111/j.1751-0813.2003.tb12566.x

    • Search Google Scholar
    • Export Citation
  • 4.

    Haupt JL, McAndrews AG, Chaney KP, Labbe KA, Holcombe SJ. Surgical treatment of colic in the miniature horse: a retrospective study of 57 cases (1993-2006). Equine Vet J. 2008;40(4):364-367. doi:10.2746/042516408X295473

    • Search Google Scholar
    • Export Citation
  • 5.

    Pierce RL. Enteroliths and other foreign bodies. Vet Clin North Am Equine Pract. 2009;25(2):329-340. doi:10.1016/j.cveq.2009.04.010

  • 6.

    Schumacher J, Mair TS. Small colon obstructions in the mature horse. Equine Vet Educ. 2010;14(1):19-28. doi:10.1111/j.2042-3292.2002.tb00132.x

    • Search Google Scholar
    • Export Citation
  • 7.

    Vatistas NJ, Snyder JR, Wilson WD, Drake C, Hildebrand S. Surgical treatment for colic in the foal (67 cases): 1980-1992. Equine Vet J. 1996;28(2):139-145. doi:10.1111/j.2042-3306.1996.tb01606.x

    • Search Google Scholar
    • Export Citation
  • 8.

    Ruggles AJ, Ross MW. Medical and surgical management of small-colon impaction in horses: 28 cases (1984-1989). J Am Vet Med Assoc. 1991;199(12):1762-1766. doi:10.2460/javma.1991.199.12.1762

    • Search Google Scholar
    • Export Citation
  • 9.

    Southwood LL. Early identification of intestinal strangulation: why it is important and how to make an early diagnosis. Vet Clin North Am Equine Pract. 2023;39(2):211-227. doi:10.1016/j.cveq.2023.03.007

    • Search Google Scholar
    • Export Citation
  • 10.

    Mair TS, Smith LJ. Survival and complication rates in 300 horses undergoing surgical treatment of colic. Part 1: short-term survival following a single laparotomy. Equine Vet J. 2005;37(4):296-302. doi:10.2746/0425164054529409

    • Search Google Scholar
    • Export Citation
  • 11.

    Dabareiner RM, White NA. Large colon impaction in horses: 147 cases (1985-1991). J Am Vet Med Assoc. 1995;206(5):679-685. doi:10.2460/javma.1995.206.05.679

    • Search Google Scholar
    • Export Citation
  • 12.

    Hardy J, Minton M, Robertson JT, Beard WL, Beard LA. Nephrosplenic entrapment in the horse: a retrospective study of 174 cases. Equine Vet J Suppl. 2000;32(32):95-97. doi:10.1111/j.2042-3306.2000.tb05342.x

    • Search Google Scholar
    • Export Citation
  • 13.

    Hassel DM, Langer DL, Snyder JR, Drake CM, Goodell ML, Wyle A. Evaluation of enterolithiasis in equids: 900 cases (1973-1996). J Am Vet Med Assoc. 1999;214(2):233-237. doi:10.2460/javma.1999.214.02.233

    • Search Google Scholar
    • Export Citation
  • 14.

    Lindegaard C, Ekstrøm CT, Wulf SB, Vendelbo JM, Andersen PH. Nephrosplenic entrapment of the large colon in 142 horses (2000-2009): analysis of factors associated with decision of treatment and short-term survival. Equine Vet J Suppl. 2011;43(39):63-68. doi:10.1111/j.2042-3306.2011.00376.x

    • Search Google Scholar
    • Export Citation
  • 15.

    Frederico LM, Jones SL, Blikslager AT. Predisposing factors for small colon impaction in horses and outcome of medical and surgical treatment: 44 cases (1999-2004). J Am Vet Med Assoc. 2006;229(10):1612-1616. doi:10.2460/javma.229.10.1612

    • Search Google Scholar
    • Export Citation
  • 16.

    Gardner A, Dockery A, Quam V. Exploratory celiotomy in the horse secondary to acute colic: a review of indications and success rates. Top Companion Anim Med. 2019;34:1-9. doi:10.1053/j.tcam.2018.11.001

    • Search Google Scholar
    • Export Citation
  • 17.

    van Bergen T, Haspeslagh M, Wiemer P, Swagemakers M, van Loon G, Martens A. Surgical treatment of epiploic foramen entrapment in 142 horses (2008-2016). Vet Surg. 2019;48(3):291-298. doi:10.1111/vsu.13161

    • Search Google Scholar
    • Export Citation
  • 18.

    Whyard JM, Brounts SH. Complications and survival in horses with surgically confirmed right dorsal displacement of the large colon. Can Vet J. 2019;60(4):381-385.

    • Search Google Scholar
    • Export Citation
  • 19.

    van den Boom R, van der Velden MA. Short- and long-term evaluation of surgical treatment of strangulating obstructions of the small intestine in horses: a review of 224 cases. Vet Q. 2001;23(3):109-115. doi:10.1080/01652176.2001.9695095

    • Search Google Scholar
    • Export Citation
  • 20.

    Kilcoyne I, Watson JL, Kass PH, Spier SJ. Incidence, management, and outcome of complications of castration in equids: 324 cases (1998-2008). J Am Vet Med Assoc. 2013;242(6):820-825. doi:10.2460/javma.242.6.820

    • Search Google Scholar
    • Export Citation
  • 21.

    Lopes MAF, Hardy J, Farnsworth K, et al. Standing flank laparotomy for colic: 37 cases. Equine Vet J. 2022;54(5):934-945. doi:10.1111/evj.13511

    • Search Google Scholar
    • Export Citation
  • 22.

    Pierce RL, Fischer AT, Rohrbach BW, Klohnen A. Postoperative complications and survival after enterolith removal from the ascending or descending colon in horses. Vet Surg. 2010;39(5):609-615. doi:10.1111/j.1532-950X.2010.00647.x

    • Search Google Scholar
    • Export Citation
  • 23.

    Kos VK, Kramaric P, Brloznik M. Packed cell volume and heart rate to predict medical and surgical cases and their short-term survival in horses with gastrointestinal-induced colic. Can Vet J. 2022;63(4):365-372.

    • Search Google Scholar
    • Export Citation
  • 24.

    van der Linden MA, Laffont CM, Sloet van Oldruitenborgh-Oosterbaan MM. Prognosis in equine medical and surgical colic. J Vet Intern Med. 2003;17(3):343-348. doi:10.1111/j.1939-1676.2003.tb02459.x

    • Search Google Scholar
    • Export Citation
  • 25.

    Orsini JA, Elser AH, Galligan DT, Donawick WJ, Kronfeld DS. Prognostic index for acute abdominal crisis (colic) in horses. Am J Vet Res. 1988;49(11):1969-1971.

    • Search Google Scholar
    • Export Citation
  • 26.

    Radcliffe RM, Divers TJ, Fletcher DJ, Mohammed H, Kraus MS. Evaluation of L-lactate and cardiac troponin I in horses undergoing emergency abdominal surgery. J Vet Emerg Crit Care (San Antonio). 2012;22(3):313-319. doi:10.1111/j.1476-4431.2012.00744.x

    • Search Google Scholar
    • Export Citation
  • 27.

    Puotunen-Reinert A. Study of variables commonly used in examination of equine colic cases to assess prognostic value. Equine Vet J. 1986;18(4):275-277. doi:10.1111/j.2042-3306.1986.tb03626.x

    • Search Google Scholar
    • Export Citation
  • 28.

    Mogg TD, Palmer JE. Hyperlipidemia, hyperlipemia, and hepatic lipidosis in American miniature horses: 23 cases (1990-1994). J Am Vet Med Assoc. 1995;207(5):604-607. doi:10.2460/javma.1995.207.05.0604

    • Search Google Scholar
    • Export Citation
  • 29.

    Underwood C, Southwood LL, Walton RM, Johnson AL. Hepatic and metabolic changes in surgical colic patients: a pilot study. J Vet Emerg Crit Care (San Antonio). 2010;20(6):578-586. doi:10.1111/j.1476-4431.2010.00597.x.

    • Search Google Scholar
    • Export Citation
  • 30.

    Hawkins JF, Bowman KF, Roberts MC, Cowen P. Peritonitis in horses: 67 cases (1985-1990). J Am Vet Med Assoc. 1993;203(2):284-288. doi:10.2460/javma.1993.203.02.284

    • Search Google Scholar
    • Export Citation
  • 31.

    Prange T, Blikslager AT, Rakestraw PC. Transverse and small colon. In: Equine Surgery. 5th ed. Elsevier; 2019:621-631.

  • 32.

    Southwood LL. Complications of the postoperative colic patient. In: Complications in Equine Surgery. John Wiley & Sons Inc; 2021:310-373. doi:10.1002/9781119190332.ch28

    • Search Google Scholar
    • Export Citation
  • 33.

    Brosnahan MM, Paradis MR. Assessment of clinical characteristics, management practices, and activities of geriatric horses. J Am Vet Med Assoc. 2003;223(1):99-103. doi:10.2460/javma.2003.223.99

    • Search Google Scholar
    • Export Citation
  • 34.

    Gunnarsdottir H, Van der Stede Y, De Vlamynck C, et al. Hospital-based study of dental pathology and faecal particle size distribution in horses with large colon impaction. Vet J. 2014;202(1):153-156. doi:10.1016/j.tvjl.2014.07.013

    • Search Google Scholar
    • Export Citation
  • 35.

    Smith LJ, Mair TS. Recurrent small colon obstructions in a foal age 7 weeks affected by a mandibular fracture. Equine Vet Educ. 2010;16(6):284-288. doi:10.1111/j.2042-3292.2004.tb00311.x

    • Search Google Scholar
    • Export Citation
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