Cribbing Has Multiple Causes, Management Practices Can Help

Excerpt from Crib-biting behavior in horses: A review from Applied Animal Behaviour Science Vol. 128 by Carissa L. Wickens and Camie R. Heleski

A recently published analysis of nearly 20 years of research on cribbing will provide horse owners with valuable information about the behavior and ideas for management practices that could reduce the frequency of this undesirable equine habit.

“Owners of cribbers seem genuinely interested in the behavior and are eager to learn about how they may better manage their horses,” said Carissa Wickens, assistant professor and equine Extension specialist at the University of Delaware. Wickens conducted the cribbing research analysis as a part of her doctoral program at MSU, which she completed in 2009.

Cribbing is a behavior in which horses anchor their top teeth onto some fixed object, like a fence or stall wall, pull backward, contract their neck muscles and take air into their esophagus, resulting in an audible grunt.

The behavior is known as a stereotypy – a repetitive behavior without any apparent reason or purpose. Cribbing is viewed by many horse owners as problematic and can lead to dental problems, weight loss and poor condition in horses exhibiting the behavior. It is estimated that 4.5 percent of U.S. horses, or as many as 414,000, are cribbers.

“I think if we can better understand cribbing behavior, especially the cause(s) of cribbing, we may be able to identify horses that are at risk and make improvements as necessary to their management, which would ultimately allow us to further reduce the number of horses that exhibit this and other stereotypic behaviors,” Wickens said.

Through analyzing the vast amount of research conducted on cribbing since the 1990s, Wickens found that the behavior has multiple causes and likely results from a complex combination of or interaction between factors including genetics, gastrointestinal and brain physiology, and the horse’s environment and management. According to Wickens, it is possible for horse owners to reduce cribbing behavior if certain management practices are put in place.

“I think possibly the most important message for horse owners is that the manner in which we house and manage our horses can have a tremendous impact on their behavior,” she said.

Many of the studies analyzed provided evidence that limiting a horse’s ability to engage in foraging and social behavior increases the risk of stereotypic behaviors, like cribbing. There are also some strong associations between cribbing and the horse’s diet; horses fed high-concentrate and low-forage diets may be at greater risk for developing stereotypic behavior.

“Once a horse becomes a cribber or crib-biter, it is unlikely that the horse will ever completely stop performing this behavior despite attempts from the owner to stop the horse from cribbing,” Wickens explained. “However, providing the horse with ample forage, turnout into the pasture and opportunities to socialize with other horses may be helpful in reducing the frequency of the behavior or the amount of time the horse spends cribbing.”

While no one has reported direct economic losses due to cribbing, surveyed owners perceive that cribbing has a negative effect on the monetary value of their horses, as many people will not buy a horse they know to be a cribber. Additionally, many owners try to physically prevent horses from cribbing through the use of cribbing collars and muzzles, electric fencing, distasteful treatments or paint on wooden surfaces, nutritional supplements and even surgery. Those costs, in addition to costs associated with dental work and the extra energy spent cribbing instead of grazing, could be reduced if the beneficial management practices are implemented.

Wickens believes there is still work to be done to further investigate cribbing behavior. While there are some clues already, the underlying mechanism behind the behavior still needs to be completely explained. The information researchers currently have could also have applications and implications for preventing and managing stereotypic behavior in other species. Since the horse genome is available to scientists, cribbing may provide an ideal case study on the relationship between genetics and the environment in the development of stereotypic behavior in horses.

The complete cribbing research review article can be found in Applied Animal Behavior Science. For more information on Wickens’s research, contact her at cwickens@udel.edu.