What would cause a deer to grow really long hooves? Almost every fall, we hear from a hunter who saw or killed a deer with overgrown hooves, like those in the photo above sent to us by NDA member Kyle Sutton of South Carolina. As we told Kyle, most likely this is a condition known by the technical name laminitis, but it is informally known as “foundering” in deer, horses, cows, goats and other ruminants.
Laminitis, or foundering, is usually caused by a sudden nutritional imbalance brought on by a diet high in fermentable carbohydrates like grains – especially corn. How can diet result in overgrown deer hooves? A review of available research on this condition in wild deer provides the chain of events.
Low Forage, High Carbs
When a deer’s diet shifts abruptly to more carbohydrates and starches without adequate fiber, fermentation of the carbs and starches leads to a drop in the pH of the digestive tract, known as acidosis. This causes metabolic imbalance and reduced blood flow to extremities, especially the hooves, which leads to inflammation of the tissues that support the bones of the foot. The pain of inflammation causes deer to walk less or walk differently, thus they “founder,” which means to became lame or disabled. Foundering leads to reduced wear on the hooves, which leads to excessive growth.
Research has documented the condition in mule deer, moose and other wild ruminants as well. A study in North Dakota moose suggested laminitis could have resulted from consumption of planted crops such as corn and wheat, access to bait piles mainly intended for deer, access to cattle feeding sites, and access to recreational feeding sites.
Obviously, deer corn and high-protein feeds don’t automatically cause laminitis in all deer that eat these foods, or we’d see snow-ski hooves on a lot more deer, in a lot more places. It’s a fairly rare condition that requires a collision of low dietary fiber combined with a sudden availability of high-carb, high-starch or high-protein feed. For example, if natural forage and browse are severely lacking in an area due to poor habitat management or high deer density, and you suddenly supply a bunch of bait during hunting season, problems are more likely.
Habitat Management Saves the Day Again
Kyle told us he only uses bait before hunting season for a trail-camera buck inventory, but he said this year there is a 500-acre corn field on the property where the buck was killed. Since laminitis is a chronic condition and deer hooves don’t lengthen overnight, it’s not likely one factor like a large corn field is to blame. Determining the primary cause in any case like this is difficult.
If natural forage and browse are severely lacking in an area due to poor habitat management or high deer density, and you suddenly supply a bunch of bait during hunting season, problems are more likely.
However, the fact that laminitis is a real thing reinforces the importance of quality habitat management whether or not you also provide feed or bait. Ensuring adequate natural forage through early succession plants, and through managing deer density, means all deer have adequate browse all year long, no matter what else they are eating. This not only prevents health problems like foundering, it increases deer health overall!
Remember that acute acidosis can kill deer. One of the most common causes of this is when people feed deer “emergency food” in winter. In harsh winter conditions, if deer stomachs aren’t accustomed to high-carb, high-starch foods, a sudden flood of those foods can cause acidosis. Again, the best “emergency food” for deer in winter is more of the browse they’ve been eating and are adapted to survive on. Habitat management saves the day again!