Foot care for cattle: many hoof problems can be avoided with good conformation and management practices.
Wet weather/muddy ground creates more incidence of foot problems in cattle. Sole injuries, infection of the skin around the hoof, and foot rot are all more likely to occur when wet conditions soften up the tissues and makes them more vulnerable to bruising and injury (nicks and scrapes) that open the way for infection. The animal may need antibiotics, medication to help relieve pain, and in some cases foot trimming or surgery. Pain can also be caused by overgrown/misshapen hooves or severe hoof cracks.
Foot rot occurs when bacteria found in soil or manure invade the foot through a break in the skin (usually between the toes or at the heel). The foot becomes swollen and inflamed (the skin around the hoof becomes red), resulting in severe lameness. The swelling and lameness come on very suddenly. The animal may be fine one day, and the next day the foot is too sore to put weight on it.
Several bacteria can cause foot rot, but the most common culprit is Fuso-bacterium necrophorum. Any scrape or injury to the skin can open the way for bacteria to enter. A small scratch or puncture--from walking through stubble or sharp gravel, ice or frozen mud-is all it takes. These bacteria can live a long time in the soil, and seem to persist in wet areas around springs or in swampy ground or wet pastures. The skin around the feet become soft and tender when wet, so foot rot is a common problem in wet weather or when cattle must walk through wet ground or bogs.
Once bacteria enter, inflammation starts quickly and the foot becomes swollen-especially between the toes or at the heel, and around the coronary band just above the hoof, depending on the site of entry. The toes may be spread apart by the swelling. In severe cases the swelling will extend upward to include the fetlock joint. On first glance you may think the animal has a sprained or broken foot because of the swelling and extreme lameness.
The animal may have a fever, and be too sore to travel to feed or water. It spends most of its time lying down, losing weight. As the infection becomes more chronic, the swollen area may crack and ooze, spreading more bacteria around the pasture. In a long-standing case the infection may invade the joints and produce a septic arthritis and permanent crippling.
Many cases of foot rot eventually clears up without treatment, but the animal is lame a long time and may lose a lot of weight--as well as spreading bacteria during the time the foot is swollen and discharging. It's always better to treat it than wait to see if it will clear up on its own. If you can clear it up quickly there will be less contamination of pen or pasture, less weight loss, and much less risk for permanent damage to the foot. With treatment, most cases heal quickly, especially if you start treatment the first or second day of lameness.
Long-acting oxytetracycline or procaine penicillin works well for foot rot, and sulfa is also helpful in severe cases. Long-acting sulfa boluses given in conjunction with oxytetracyline coverage for three to five days will usually clear it up. Disappearance of lameness is a sign of recovery. A long-standing case may need more extensive treatment, however. It is sometimes necessary to clean the foot, apply local antiseptics, and bandage the foot in conjunction with use of systemic antibiotics. If joints or tendon sheaths are involved, the prognosis for recovery is poor; surgery to remove the affected claw/ toe may be necessary.
There is a vaccine (Fusogard) for control and prevention of foot rot, and tests have shown a 64 percent reduction in cases when vaccinated cattle were compared to non-vaccinated cattle. Label recommendations for use of the vaccine suggest vaccinating cattle at six months of age or older with an initial two-shot series 60 days apart, with an annual booster thereafter. Total reliance on vaccine for control of foot rot generally does not work, however; it is most effective when used in conjunction with other preventative measures such as maintaining good hoof health with proper nutrition and a clean, dry environment.
Often called hairy heel warts, "strawberry heel," or digital dermatitis, this problem is caused by bacteria that infect the soft tissue of the foot. It generally occurs between the toes or up the front or back of the foot. Young cattle seem most susceptible because they have not developed any immunity to the bacterial infection. Moist conditions can predispose cattle to heel warts if these bacteria are present; if the foot is wet the skin is more soft and tender, and more vulnerable. Best prevention is a clean, dry environment, and healthy feet.
This condition is treated with antibiotics and a topical antiseptic on the affected area. The foot may have to be sprayed daily for about five days with the antiseptic, or wrapped. There is a vaccine for heel warts, to prevent this infection, but it only works if the animal is not already infected. For best protection the animal is given a three-shot series (once a week) the first year, and then an annual booster thereafter.
Bacteria may enter the hoof itself through a crack or bruise, usually on the bottom of one of the digits. A bruised sole (as from stepping on a sharp rock, or from uneven weight bearing due to misshapen foot) may eventually become an abscess. Sometimes the layers of the sole will separate and a "false sole" develops--with pus in between the layers. The infection may eventually break out the side or at the heel.
With an abscess, initially there is no swelling above the hoof, since the infection is confined to the hoof itself. If a lame animal does not have a swollen foot, an abscess (rather than foot rot) should be suspected and the bottom of the claws/toes should be carefully inspected. A crack or bruise should be probed with a hoof knife to find the abscess and open it up. In some cases it may need to be flushed and drained. The infection creates a foul-smelling fluid that will be obvious when the abscess is located and opened.
Treatment generally consists of paring away all the affected horn tissue around the abscess, and minimizing the weight bearing in that area until new horn can grow and fill in the hole. This can be accomplished by paring the affected claw so that the sound one bears the weight, or by gluing a "shoe" or wood block to the sound claw to build it up so it bears all the weight.
Lameness can also be due to laminitis (inflammation of the lamina- the interfacing tissues that connect the sensitive inner parts of the hoof and bone to the outer insensitive horny shell). Laminitis is often due to digestive problems that upset the balance of rumen bacteria, creating toxins that can enter the bloodstream and cause serious changes in the hoof. Most common causes of laminitis are grain overload--as when cattle are put on grain too fast (not allowing a gradual period of adjustment to the higher grain ration) or changes in diet are too sudden, such as changing from barley to hull-less barley or wheat (feeds that contain less roughage).
Just as in a horse with laminitis, the feet become very tender due to the ensuing inflammation. If the affected lamina separate, disrupting the connection of bone to hoof horn, the feet become deformed as the bone shifts and growth patterns change-with toes becoming overlong and curling upward. An animal that has foundered will always tend to go lame easily, due to sole bruising.
Sometimes called "sand cracks," this problem seems to occur most often in heavy, older cows or bulls (rarely in calves or heifers) and most often in feet that are allowed to grow too long. Most common is a crack up the center of the toe. This is sometimes due to poor hoof horn that tends to become dry and brittle; the hoof loses its ability to stay hydrated and flexible. Sometimes a dietary deficiency (forages low in copper or zinc) can lead to loss of hoof quality, and subsequent cracking.
In some geographic regions, high levels of iron, molybdenum or sulfur may tie up copper and accentuate copper deficiency. Forages growing on alkali ground may also be low in copper and zinc. If a herd is having trouble with hoof cracks, mineral supplementation (especially the use of chelated zinc and copper, which seems to be better utilized by the body) may help.
Excessive selenium in the diet can also lead to hoof cracks, and in severe cases, loss of the entire hoof wall. Many areas of the country are deficient in selenium, but there are a few places where selenium levels are high enough to be toxic, causing loss of tail hair and severe hoof cracks. Over-supplementing with selenium can also cause hoof cracks, since the window of "healthy" levels for this important trace element is small. Too much is just as detrimental as too little.
Hoof cracks are often more unsightly than damaging, but if they become deep, or the hoof wall starts to split at the toe, they can lead to infection of the deeper tissues and severe lameness. Toes that grow overlong often tend to crack, so keeping the foot trimmed (if it can't wear normally) can usually keep cracks from becoming a serious problem.
In some cases a hoof sealer or hoof glue can be used to protect the outer surface of the foot and prevent cracking. There are some bovine hoof products that form a bond with the hoof wall to create a tough, outer surface that repels moisture and makes it stronger. It keeps the hoof from getting soft in wet conditions and holds in natural moisture--to keep the foot from drying out and cracking in dry conditions.
Preventing foot problems
Many problems can be avoided by selecting cattle with good foot and leg conformation, so that hooves grow in proper alignment and balance and wear normally. A tendency toward foot problems is sometimes inherited, due to poor foot/leg angles or to inability to grow tough hoof horn. Just as in horses, whether an individual has tough, resilient hooves or poor quality hoof horn is partly due to genetics. If you have a lot of hoof problems (such as toe cracks) in your herd, check to see if the problem animals are related. You may have used a bull whose daughters have less than average hoof quality.
If cattle are kept on soft pastures and never have a chance to travel on firm or rocky ground to wear the feet, periodic hoof trimming may be necessary to keep hooves from growing too long. Footing is an important issue for healthy feet. Abrupt changes in footing can create problems, as when cattle are brought from a wet, swampy pasture to a pen/pasture with rocky conditions or even into an auction or feed yard with rough concrete around the feed bunks for good traction. The abrasive footing may quickly wear away the soft feet and leave them vulnerable to bruising or infection, creating serious lameness. If the sole is worn away and infection affects the bone, the animal may not recover.
Proper nutrition is also important for healthy hoof growth, to avoid poor hoof horn and cracking that opens the way for infection. Nutrient imbalances and deficiencies can lead to poor horn growth or dry, brittle feet that are prone to cracking. Hoof health is affected by some of the trace minerals like zinc, copper, manganese and selenium. If these are inadequate (or diet is low in vitamins A, D and biotin), hoof horn may be adversely affected and not grow properly. Fatty acids in diet also play a role in growing healthy, resilient hoof horn that does not dry out and crack. Green forage plants generally contain all the elements of diet needed for hoof health, unless soils are very deficient in certain minerals.
A dry, clean environment will also prevent many foot problems. Environmental conditions can predispose even a healthy hoof to problems--if cattle are in wet pastures year round, or spend the winter in a muddy pen or must travel over sharp rocks. Providing mounds of dry ground in wet pens (higher areas that stay well drained) can help prevent foot rot, for instance, enabling cattle to stand in dry areas instead of having their feet constantly in mud.
Another management technique that can provide drier footing in wet pens and boggy gateways is use of a porous high-strength filter fabric to hold a layer of gravel near the ground surface (similar to what is used in highway construction). The porous fabric allows water to drain down through it, but it holds the crushed rock or gravel in place so it doesn't keep sinking down into the mud, keeping the top layer of soil drier. These filter pads can be used in feeding areas, travel lanes, gateways, etc.--wherever cattle tend to "bog down" in wet weather.
The geotextile or grid fabric can be installed by excavating the top six to eight inches of soil in the pen/ roadway and putting the filter pad at that level. Then four to six inches of crushed limestone or similar rock can be placed on top of the fabric, and topped with two to three inches of finer material such as fine crushed rock. This creates an effective "drain" for moisture, keeping the top dry and healthier for hooves. Buildup of manure on top of the fine gravel (as in a pen or feed yard) can be easily scraped up and periodically removed without damaging the filter.
Any management procedure that helps eliminate hoof damage and aids hoof health can help prevent foot rot, sole bruising, etc. If pens are clean and free of sharp stones or frozen, rough mud, many hoof injuries and infections can be prevented. Covering frozen ground with straw, and keeping pens well drained in wet weather can help prevent foot injuries. Concrete slabs at feed bunks or water troughs (areas that tend to get very boggy) can help keep feet clean and dry.
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|Title Annotation:||caring for lame cows|
|Author:||Thomas, Heather Smith|
|Publication:||Countryside & Small Stock Journal|
|Date:||Mar 1, 2008|
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