Hoof health and lameness in dairy cows and heifers remains a challenge for the dairy industry. Preventing and treating lameness is a never-ending task for dairy farmers. Rarely do we find a dairy farm that doesn’t have a cow or two favoring a foot that needs attention. It may be due to neglected hoof trimming, injury, digital dermatitis or laminitis.
Some lameness in dairy cattle can be congenital or the result of injury to the hip and pelvis. By far the majority of lameness in dairy cows, however, is the result of poor hoof care and from pathogenic bacterial challenges. Lameness can also originate from inside the foot as a result of inflammation from laminitis.
Proactive response to foot issues
To stay ahead of foot problems dairy farmers must give heed to the conditions of alleyways and barnyards as well as cow comfort. They also must regularly review herd nutrition and feeding protocols. Time spent on hoof care and proper nutrition with a veterinarian and nutritionist will pay off in the long run.
Cows are completely dependent upon dairy farmers and managers for their hoof health and good animal husbandry dictates that they take proper care of their cows’ feet. Beyond treating the cow humanely, the issue ultimately comes down to cow comfort and her ability to be ambulatory, get to and from the milking parlor, feed bunk and waterers. Not closely monitoring foot health in a dairy herd will have a profound impact on milk production and profitability. Anything that affects the cow’s ability to eat, sooner than later, will have a negative effect on milk production. Cows that can’t walk cost money.
Hoof trimming is vital
Every cow on the dairy should see the hoof trimmer once a year at a minimum – several times per year is even better when there are known problems such as heel wart. Yes, it’s another job that has to be scheduled and managed. Hoof trimming should be part of the regular herd management routine just like vaccination programs and dry cow treatments. If every cow gets her feet trimmed at least once a year, there’s much less chance of foot problems in the future.
A cow is a big animal that distributes a lot of weight on four relatively “stumpy posts.” The hoof is designed to distribute that weight as evenly as possible. Interestingly, the more hours a cow stands, the more quickly her hoof will grow. The harder and the rougher the surface a cow has to stand on will also accelerate hoof growth. So cows that spend many hours standing on hard concrete will grow hoof more rapidly than a cow that spends most of her time standing in a dirt lot or pasture. Cows that spend their entire lives on concrete must have their hooves trimmed more often. Hoof growth will vary on the claws depending on how a cow stands while eating. Any condition that irritates the foot’s sole responds by adding more hoof.
A dairy farm that has its own hoof trimming table or chute and staff that knows how to trim feet properly is in a better position to be proactive on foot health. Problems can be managed in a timely manner rather than having to wait days or weeks to get the hoof trimmer out.
Nitty-gritty of how cows walk
It’s important to understand the mechanics of how a cow walks. As cows walk they tend to put more weight on the outside claw of the rear feet and the inside claw of the front feet. When examining and trimming feet the trimmer needs to pay closer attention to those claws. Hoof trimming is a fairly complex process and an improperly trimmed hoof will cripple a cow just as quickly as not trimming a hoof at all. If trimming is neglected, hooves will become very misshapen and cause cows to shift their weight to compensate for the discomfort. Cows can become so crippled they will never be able to walk correctly.
Cows’ hooves are very susceptible to softening if they are left to stand in wet or muddy conditions for extended periods of time. Once the hoof material becomes soft, it can be easily bruised, opening the door for infections and abscesses. A condition known as foot rot can also set in when the foot is exposed to certain bacteria in wet and muddy conditions. Keeping the barnyards free of wet and muddy conditions as well as stones will help keep foot rot under control and reduce bruising. Reducing the amount of cement curbs where cows can trip and stumble will also reduce foot injuries.
The pressure exerted by the pedal bones on the top of the hoof at the time of trauma can cause injury and bruising to the coronary cushions, breaking blood vessels and causing hematomas that can turn into abscesses and ulcers. Abscesses and ulcers must be opened on the hoof and allowed to drain and heal. Often, a block is placed on the opposite claw to raise the foot off the ground and keep pressure off the injured claw. (Shown above.)
Watch out for hairy heel wart
Digital dermatitis – commonly known as the hairy heel wart – has become an insidious hoof health challenge in dairy herds. The clinical name is papillomatous digital dermatitis, because what we refer to as a “wart” is really a papilloma. Digital dermatitis is an infection caused by a combination of many bacteria that work in conjunction with one another to create the wart. The conditions favoring infection are generally unhygienic, moist, humid and muddy conditions in which cows must walk or stand. While digital dermatitis is not fatal, it does cause lameness due to the tenderness of the warts. If left untreated, large warts can become infected. However, cows will be suffering from severe lameness long before infections set in. Digital dermatitis is highly contagious and once it infects a herd is nearly impossible to eliminate.
While the bacterium causing the heel wart are ubiquitous and cannot be eliminated, the conditions that favor the establishment of heel warts in a herd can be managed. When skin is made soft by continuous exposure to moist and dirty conditions a cut or nick from a stone or pebble or a scrape from a jagged piece of concrete allows bacteria to enter. On a cow’s foot the most susceptible area is the fleshy areas between the claws and on the heel. (See hoof photo above.)
The warts can be treated easily with the application of wraps containing antibiotic ointment when the cow is on the trimming table (shown above). Topical antibiotics such as tetracycline have been shown to reduce wart problems. Preventing the wart is preferable to treating and since the bacterium thrives in moist conditions, providing dry and clean walking and bedding environment for cows is the best way to prevent or reduce incidence of digital dermatitis in dairy herds.
Copper sulfate foot baths have been demonstrated to reduce prevalence of heel wart by firming up hoof material and killing bacteria. It is highly recommended that all dairy farms, especially those with free stall housing and milking parlors, install a footbath for all cows to walk through at least several days per week. Foot baths can be installed permanently in concrete alleyways or can also be a moveable plastic tub placed in an alleyway. (Shown right.) It’s important when using foot baths that an adequate level of copper sulfate is used and the bath is cleaned and changed regularly once it becomes contaminated with manure.
Risk of laminitis in high-yield herds
Especially in high-producing dairy herds, laminitis is responsible for a high percentage of lameness. Laminitis, also known as coriosis, is an inflammation in the laminar area of the foot where the flesh of the leg transitions to hoof. Redness, puffiness or swelling of the foot, just above the hoof and in the area of the dew claws, is an early indication that a cow has laminitis.
The cause of laminitis is believed to be associated with a disturbance in the microcirculation of blood in the corium, which leads to breakdown of the dermal-epidermal junction between the hoof and pedal bone. Vasoactive substances such as histamines are released into the bloodstream and particularly affect areas such as the corium where there are many small blood vessels. The inflammation and swelling causes the pedal bones to settle lower in the hoof, which places more pressure on the sole, resulting in a sole ulcer. The sole ulcer must be opened and allowed to heal (shown below).
Rumen acidosis is considered to be a major predisposing cause of laminitis. Release of histamines into the bloodstream is an immune response to the acidosis. The key to limiting laminitis caused by acidosis is proper nutrition management. Avoid abrupt changes in diets, especially in high-producing diets that include a high proportion of grains.
In many herds it’s the fresh cows that are most prone to laminitis a few weeks into the lactation. It’s common for those cows to go from a diet low in starches and other low-fiber carbs to a diet quite high in those feed ingredients. Nothing will upset a rumen more quickly than making big changes in feed ingredients that will upset the balance of micro-organisms necessary for feed fermentation. Combine that with any accompanying heat stress at the time of freshening and many dairies will have a higher incidence of laminitis in their fresher cows a couple of months later.
Not every cow experiencing a periodic bout of acidosis will come down with laminitis at a later date. Avoiding overcrowded barns where cows stand for many hours and have limited access to feed and water on a hot, humid day will help reduce the chances of laminitis problems developing later. Cows that have experienced some level of acidosis during the heat but have access to pasture appear to have less propensity to develop laminitis than cows that spend all of their time on concrete.
Other indicators that a herd may be prone to laminitis are a low milk butterfat test, extra sloppy and foul-smelling manure and poor cud chewing. Poorly balanced diets with low effective fiber are believed to be the leading cause leading to acidosis and laminitis. Any time the cows are at rest, over half of them should be chewing their cud. This is an indication that their rumens are working and they are not acidotic. Chewing of the cud creates more saliva, which is then used to buffer the rumen. Including mineral complexes such as zinc/methionine in the diet has been shown to improve hoof integrity. Twenty mg/cow/day of the vitamin biotin has also been shown to reduce sole ulcers.
Lameness on our dairies is costly, as it results in loss of milk revenue and premature culling of cows. Dairies plagued with ongoing issues of lameness need to reevaluate nutrition and feeding programs as well as herd management, cow comfort and hoof trimming care. As part of their overall herd management, dairies should include regularly scheduled hoof trimming and hoof health evaluations, which involve the hoof trimmer, veterinarian and nutritionist.
Hoof care isn’t something that’s done only when cows are having problems, and the hoof trimmer is finally called out when there are more than 10 cows limping around the barn. It’s important to develop a trusting relationship with a hoof trimming professional who understands cows and can trim feet and treat infections as well as offer advice as to why problems are occurring in a herd’s feet. A competent hoof trimmer will be proactive on hoof health management and make a dairy farm money.