External supporting research Colic risk & prevention Peer reviewed EXT-S10

Risk Factors for Colic in Horses: Multicenter Case-Control Study

A multicenter case-control study comparing 406 horses with colic and 406 non-colic controls identified associations between colic risk and factors including water access, concentrate and whole-grain corn intake, parasite control, previous colic history, outdoor management, age and breed.

Original study title

Risk factors for equine acute abdominal disease (colic): Results from a multi-center case-control study

Colic Colic risk factors Horse management Water access Concentrate feeding Carbohydrate intake Parasite control Previous colic

Study at a glance

Year 1996

Study type Multicenter case-control epidemiological study

Sample 812 horses: 406 colic cases and 406 non-colic controls

Duration March to December 1991

Population Horses admitted to five university veterinary hospitals, including horses presenting with acute abdominal pain and randomly selected non-colic hospital controls

Publication Peer-reviewed journal article

EquiNectar tested? No

Peer reviewed Yes

Open access No / not specified

Relationship External supporting research

812

Horses included in the final analysis

406

Horses admitted with colic

2.2

Odds ratio for colic with outdoor access but no continuous water supply

0.11

Odds ratio associated with daily worming product use

Research question

What did the researchers want to understand?

Which horse-level, dietary, management and environmental factors are associated with acute abdominal disease, or colic, in horses admitted to multiple university veterinary hospitals?

Researchers

Study authors

Mathew J. Reeves

MSU College of Human Medicine

Mo D. Salman

Colorado State University

Gary Smith

University of Pennsylvania

Research organizations

Research institutions

Tufts University

University
United States

University of Pennsylvania

University
United States

The Ohio State University

University
United States

University of Guelph

University
Canada

Cornell University

University
United States

Methodology

How the study was conducted

Study design

This was a hospital-based multicenter case-control study designed to identify factors associated with acute equine abdominal disease.

Horses admitted with abdominal pain between March and December 1991 were recruited through veterinary hospitals at Cornell, Guelph, Ohio State, Pennsylvania and Tufts universities.

Control horses were randomly selected from other non-colic admissions to the participating hospitals.

The final analysis included 406 colic cases and 406 controls.

The person responsible for the horse's day-to-day care completed a telephone questionnaire covering potential management, dietary, environmental and horse-level risk factors.

Researchers used multivariable logistic regression to determine which factors were independently associated with colic case status.

What was measured

Researchers compared horses admitted with acute abdominal pain with non-colic horses admitted to the same university veterinary hospitals.

The person responsible for each horse's day-to-day care completed a telephone questionnaire.

Information was collected on horse characteristics, feeding, management, outdoor access, water provision, parasite control, previous colic history and other potential risk factors.

Potential associations with colic were evaluated statistically.

Multivariable logistic regression was used to identify factors independently associated with whether a horse was a colic case or a non-colic control.

The analysis also investigated interactions between risk factors, including interactions involving age, drylot use, previous colic history and the person responsible for day-to-day care.

Study findings

Key results

• The final analysis included 406 horses with colic and 406 non-colic control horses.

• Horses were recruited through five university veterinary hospitals.

• Age, breed, outdoor access, outdoor water supply, parasite-control practices, concentrate intake, whole-grain corn intake, previous colic history and characteristics of the horse's day-to-day care were significantly associated with colic risk.

• Horses using outdoor enclosures without a continuous water supply had more than twice the odds of being colic cases compared with horses with adequate outdoor water, OR 2.2, 95% CI 1.2-4.3.

• Use of a daily worming product for at least 60 days during the previous 12 months was associated with lower odds of colic, OR 0.11, 95% CI 0.02-0.55.

• Increasing whole-grain corn consumption was associated with increased colic risk.

• The relationship with total non-roughage concentrate intake differed from the whole-grain corn finding, demonstrating that dietary associations were not straightforward.

• Previous colic history was among the factors associated with colic risk.

• Arabian horses had approximately twice the odds of being colic cases compared with the Thoroughbred reference group, OR 2.0, 95% CI 1.0-3.9.

• Standardbred horses had lower odds relative to the Thoroughbred reference group, OR 0.6, 95% CI 0.4-1.0.

• The authors concluded that equine colic has a complex multifactorial risk profile involving stable management, outdoor environment, water access, carbohydrate intake, parasite control and intrinsic horse factors.

Interpretation

What do the findings mean?

This study provides epidemiological evidence that equine colic risk reflects a combination of management, dietary, environmental and intrinsic horse factors.

The final analysis compared 406 colic cases with 406 controls recruited through five university veterinary hospitals.

Horses with outdoor access but without a continuous water supply had more than twice the odds of being colic cases compared with horses provided with adequate outdoor water.

Whole-grain corn consumption was associated with increasing colic risk, although the relationship between total concentrate intake and colic was more complex and should not be reduced to a general claim that concentrate feeding causes colic.

Previous colic history, parasite-control practices, type of outdoor enclosure, age and breed were also associated with colic risk.

The results reinforce the view that colic prevention should focus on overall horse management rather than any single dietary intervention.

In practice

Why this research matters

Colic is not one disease with one cause. It is a clinical syndrome influenced by multiple interacting horse, feeding, management and environmental factors.

In this study, access to water was particularly relevant. Horses with access to outdoor enclosures but without a continuous water supply had more than twice the odds of being colic cases compared with horses with adequate outdoor water.

Dietary associations were more complex. Greater whole-grain corn consumption was associated with increased colic risk, but the relationship between total non-roughage concentrate intake and colic did not follow the same pattern.

Previous colic history, parasite control, outdoor management, age and breed were also associated with risk.

For horse owners, the findings support a whole-management approach to reducing avoidable colic risk, including reliable access to water, appropriate feeding practices, parasite management and particular attention to horses with a previous history of colic.

Research transparency

Study limitations

This was an observational case-control study. Associations identified between management factors and colic therefore do not by themselves establish that those factors caused the colic episodes.

Cases and controls were selected from horses admitted to university veterinary hospitals. The population may therefore differ from horses experiencing colic or remaining healthy in the wider general horse population.

Management and feeding information was obtained through telephone questionnaires completed by the people responsible for the horses' day-to-day care. The study therefore depended on accurate recall and reporting.

The study was conducted using horses admitted between March and December 1991, so feeding, parasite-control and general management practices may differ substantially from modern horse management.

Some associations were complex. For example, increasing whole-grain corn consumption was associated with greater colic risk, while increasing total non-roughage concentrate intake was associated with lower risk when concentrate feeds were considered together.

The study identified statistical associations with colic as a broad syndrome and should not be interpreted as showing that the same risk factors apply equally to every specific type of colic.

The findings are best interpreted as evidence for the multifactorial nature of equine colic rather than as a list of individual proven causes.

EquiNectar context

How this research relates to EquiNectar

This research did not test EquiNectar and was conducted independently of Tharos Ltd.

Its relevance to the EquiNectar Science Center lies in the wider context of digestive health and colic risk management.

The study demonstrates that equine colic is multifactorial. Factors associated with colic included water availability, concentrate and whole-grain corn intake, parasite control, previous colic history, outdoor management and intrinsic factors such as age and breed.

Carbohydrate intake was therefore one component of a much wider management picture rather than a single explanation for colic.

This distinction is important when considering nutritional strategies intended to support digestive health. Published EquiNectar research separately investigates digestive and microbial outcomes associated with EquiNectar supplementation.

This study provides no evidence that EquiNectar prevents or treats colic, and its findings should not be interpreted as demonstrating that any individual feed or supplement can eliminate colic risk.

Tharos / EquiNectar involvement

None. This study was conducted independently of Tharos Ltd and EquiNectar. EquiNectar was not evaluated in the research.

EquiNectar evaluated No

Source record

Publication details

Journal

Preventive Veterinary Medicine

Publisher

Elsevier

Year

1996

Volume

Issue

3-4

Pages / article

285-301

DOI

10.1016/0167-5877(95)00551-X

PMID

Leave blank

Species

Horses

Population

Horses admitted to five university veterinary hospitals, including horses presenting with acute abdominal pain and randomly selected non-colic hospital controls

Sample

812 horses: 406 colic cases and 406 non-colic controls

Duration

March to December 1991

Setting

Five university veterinary hospitals in the United States and Canada

View original source ↗

Recommended citation

Reeves MJ, Salman MD, Smith G. Risk factors for equine acute abdominal disease (colic): Results from a multi-center case-control study. Preventive Veterinary Medicine. 1996;26(3-4):285-301. doi:10.1016/0167-5877(95)00551-X.

Risk Factors for Colic in Horses: Multicenter Case-Control Study

What did the researchers want to understand?

Study authors

Mathew J. Reeves

Mo D. Salman

Gary Smith

Research institutions

Tufts University

University of Pennsylvania

The Ohio State University

University of Guelph

Cornell University

How the study was conducted

Key results

What do the findings mean?

Why this research matters

Study limitations

How this research relates to EquiNectar

Publication details

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