Foot Rot in Beef Cattle.

 By Heather Smith Thomas.

Foot rot is an infectious condition that causes swelling, heat and inflammation in the foot, resulting in severe lameness.  Swelling and lameness appear suddenly.  One day the animal is fine, and the next day the foot is so sore the animal may not put weight on it.

Dr. Matt Miesner, Kansas State University says some years there are more cases.  “We know that the primary pathogen that causes foot rot, Fusobacterium necrophorum, is always in the environment because it is in the animals’ digestive tract and passed in feces.  There may a combination of pathogens that work together, but this one is always there. 

Sometimes it seems to work together with other intestinal bacteria that contaminate the environment.  Fusobacterium necrophorum is usually the one causing severity of clinical signs but often there are multiple pathogens working together to get the infection going.”

It’s hard to know what makes cattle more at risk some years.  There may be some variation in the strains of bacteria and some may become more pathogenic, but varying incidence of disease may be more related to environmental factors.  

“Maybe we had a dry spell and the feet become dry and hard, and then there’s moisture and the feet become soft and more easily punctured, scratched and bruised.  We see a lot of cases when cattle are on stubble and get scratched/poked between the claws.  It doesn’t take much of an opening for bacteria to get started in the tissues,” says Miesner.  Walking on gravel or sharp ice may create nicks and abrasions.  You might see foot rot any time of year because the bacteria are always there but it usually takes moisture to soften the skin.

“The producer may bring in an animal to treat for a hoof abscess and when I get that animal on the table and look at the foot, it may turn out to be foot rot.  We may not see foot rot for several years, and then all of a sudden we see a bunch.  Season, moisture and environmental conditions may play a role.  Once you get a few cases, the bacteria may be spread around more (from draining lesions) with higher concentration in the environment.  Once you have it, this tends to amplify it,” he says.

Foot rot can affect cattle at any age.  “I see foot rot in small calves as well as older cattle.  They may be in a wet, boggy pasture in early spring, or vulnerable in hot, humid weather in the summer.”

Make Sure It’s Foot Rot
Sometimes a person assumes the animal has foot rot just because it is suddenly lame, but it’s wise to look at the foot and make sure, in order to deal with it properly.  Sudden three-legged lameness is the classic sign of foot rot, but could also be due to a fracture, snakebite, puncture, abscess, or some other type of infection.  “I’ve occasionally seen cattle with a rock or stick jammed up between the toes, making the animal reluctant to put weight on the foot,” says Miesner.

“Examine the foot before you give antibiotics, in case it’s something else that needs to be addressed,” he says.  If you are putting the animal into a chute for treatment, you can examine the foot (at the heel and between the toes) and lift it up with a rope if necessary to look at the bottom of it.  If you are roping the animal out on pasture, it can be head-and-heeled and cast on the ground, allowing for treatment and for close examination of the affected foot.

“Swelling of the foot and lower leg may be due to snakebite or other injury, but in some cases of foot rot the swelling starts up the limb because of the inflammation,” he says.  Snakebite will usually show fang marks in the swollen area, and those may be draining after infection sets it.  By contrast, any oozing/drainage from foot rot is generally right between the toes, with a very foul odor.

Foot rot will generally respond quickly to antibiotics, especially if treated early.  “If the animal doesn’t improve, if it’s not better in a couple days, we need to take a closer look to see if it’s some other problem.  I’ve seen cases where a cow had wire wrapped around a foot, or an abscess.  Just lifting the foot to examine it can be helpful,” he says.

Treatment
“The treatment I prefer is to lift the foot and use a piece of gauze soaked with Betadine to floss the area between the toes.  This gently opens the tissue and helps air get to it, which tends to inhibit bacteria that love anaerobic conditions.  The organisms that cause foot rot are still very responsive to antibiotics.  There are several labeled for treating foot rot, including oxytetracycline and penicillin, as well as some of the newer ones.  Most people still use long-acting oxytetracycline or Procaine penicillin because they are cheaper, and save the big guns for more serious problems.”

Systemic antibiotics generally work well, and a person can also clean up the foot and apply a topical antibiotic such as oxytetracycline.  “Anti-inflammatory medication can also help, to relieve pain, swelling and fever.  Now we have the topical (transdermal) form of Banamine, labeled for pain and fever.  It is now used in feedlots for foot rot.  This is something you could discuss with your veterinarian as an easier method of administering Banamine,” Miesner explains.  Earlier, this drug was only labeled for intravenous use in cattle.

“If the animal is not greatly improved (no longer lame) within 3 to 4 days after antibiotic treatment, I look for some other cause of the infection and lameness or to see if it’s gone into deeper tissues.”  Foot rot treated early should resolve quickly.  If you don’t see the cattle very often (such as in big range pastures) and a case of foot rot has been going on for awhile, it may be harder to clear up.  When you find a lame animal in that situation, you don’t know if she’s been lame for 2 days or 2 weeks.

“The infection will hopefully break out and clear up on its own, but sometimes it keeps going deeper and may get into the rest of the foot and the joints.  That can become a nightmare to treat and clear up,” he says.

“What we call second-stage foot rot or ‘super’ foot rot can be challenging, when it goes deeper and gets into the coffin bone or the joint.  We want to catch it before it gets to that stage.  Treating those takes a lot of care and aggressive intervention.”

Prevention
“Since foot rot is so responsive to antibiotics, there are some feed-through antibiotics such as oxytetracycline and chlortetracycline labeled for preventing foot rot.  If the veterinarian or producer is anticipating issues with foot rot in certain situations, this might be something to consider,” says Miesner.  This might work if the cattle are already being fed (in a feedlot situation) rather than out on pasture.

It also helps to isolate any animal that gets foot rot.  Bring it in and treat it, and keep it separate from the herd until the infection resolves, so it won’t be spreading the bacteria around for the others to pick up.  The pathogen can live in the environment for many months.  “Once you see a case, be vigilant to pick out any new ones and isolate them.  The earlier you can treat them, the better,” he says.

“There is a vaccine against Fusobacterium necrophorum as a preventative against liver abscesses and foot rot in feedlot cattle.  Feedlots may use the vaccine to try to limit incidence of liver abscesses, and in these situations they generally see reduced incidence of foot rot.  There are vaccines that include the Fusobacterium so if a person is having ongoing problems in situations where cattle are intensively grouped, or having repeated problems with foot rot year after year, this might be something to consider.  Vaccination may help reduce problems but won’t eliminate them,” Miesner says.

“I get mixed feelings from producers and practitioners about how well it works.  It might be something to incorporate into a management program.  It might lower the incidence of foot rot when using the vaccine to prevent liver abscesses, but there is not much data,” he says.

It can be frustrating to have a group of steers ready to sell and then some of them develop foot rot.  They can be treated, but then you have to worry about withdrawal times for the antibiotic—and you might not be able to sell those animals when you’d planned.  Prevention can be very important.

“In a pasture situation it’s hard to avoid mud some times of year.  One thing I’ve found that can help limit spread of this disease is to keep cattle from congregating in small areas.  If they are fed in a pen or pasture, the places where they congregate can become wet and mucky (as well as heavily contaminated with manure, which contains the pathogens).  If you can move the cattle, rotate feeding areas, find ways to dry out those wet spots, this may help,” says Miesner.

Try to minimize bad footing and areas that are abrasive to feet—whether rocky areas or lots of stubble.  If the cattle are on stubble that may create nicks and scrapes on the interdigital space and then they walk through water or boggy areas, they may be vulnerable.

“Some of the footing people put around waterers or watering areas to eliminate mud may be abrasive, so be careful about the type of gravel or other material put around watering areas.  Look at the environment the cattle live in and figure out the best way to manage moisture as well as abrasive surfaces—and limit the crowding/congregation of animals,” he explains.

Nutrition is also important.  Another thing that can lead to soft feet/weaker skin and hoof horn is mineral deficiency.  “If a producer is having a lot of foot rot cases, I evaluate the trace mineral program.  There is research evidence showing that if an animal is low in zinc, copper, selenium, etc. this can lead to weaker skin and feet,” says Miesner.

Iodine is also important.  “Feeding a fortified salt is important, and most of the trace mineral supplements also contain iodine.  Biotin also helps with hoof horn quality.  Thus it is important to look at the nutrition and make sure there are no deficiencies causing weakness in the feet,” he says.  It’s often hard to get rid of water and mud in their environment, but we can make sure they have adequate nutrition for hoof health.

Strawberry Foot Rot/Hairy Heel Warts/Bovine Digital Dermatitis (Paillomatous Digital Dermatitis)
“This foot lameness is caused by a different type of pathogen—a spirochete bacterium.  The lesion is usually in the back cleft between the heel bulbs.  It appears as a reddened, roughened, ulcerated irritated area.  It looks granular (like a strawberry) and is very painful.  In other stages it may have long hair-like structures that grow out from the heel.  This would be something to check for if the animal is very lame,” says Miesner.

This is more common in dairy cattle than in beef cattle, but may appear when beef animals are in a contaminated environment.  “I’ve seen this condition in bulls housed in groups or cattle in a feedlot situation.  This disease is diagnosed with a biopsy of the lesion; the bacteria can be seen under a microscope,” he says.  

Treatment is different than for foot rot.  “This disease does not respond as well to systemic antibiotics.  We usually use formalin foot baths, thoroughly rinsing the feet to try to halt the infection.  We may also use a topical oxytetracycline spray, and try to dry the foot.  Moisture is what allows these bacteria to keep going,” he explains

“Whenever there are housed animals in a wet, moist environment there’s a chance for this type of infection and it is very contagious.  It needs a little help—with moisture and disruption of the foot—but can get started quickly and is much harder to treat than foot rot,” he say

“If a lame animal has a lesion between the toes or heel bulbs and it looks like foot rot but is not responding to antibiotics, a closer look may reveal its true nature.  It pays to be aware of this possibility,” says Miesner.

Terry J. Engelken, DVM MS (College of Veterinary Medicine, Iowa State University) says digital dermatitis is becoming more prevalent in beef cattle.  “In feed yards that have it, this disease is rapidly becoming the most common cause of lameness.  We still see foot rot and other foot problems, but those are pretty straightforward in terms of intervention.  The frustrating thing about digital dermatitis is trying to manage your way around it,” he explains.  It is much more difficult to prevent and treat than foot rot.

“We generally see these lesions at the back of the foot, between the dewclaws and the coronary band/hairline.  It starts as a small erosion and works its way into deeper tissues.  The chronic, classical sign—and where it gets the name hairy heel wart—is deep erosions and proliferative tissue; it looks like hair growing out of the lesion,” he says.

Not all cattle that have these lesions are lame at first, which is frustrating when trying to diagnose it early.  The disease may quietly percolate in a pen of cattle before you notice it. “By the time you see lame cattle, there are many more with early lesions that will become lame later.  There is no consistent reason for why it behaves the way it does.  Some pens in a feed yard will get it and others won’t.  We tend to see it in a lot of pens at a particular yard—in outdoor pens, bedded packs, indoor facilities, etc.  In our area many cattle are fed in hoop buildings or mono-slope buildings.  We also see this disease in cattle in slatted-floor buildings.  This makes it very frustrating when trying to manage the pens,” says Engelken.

Digital dermatitis is caused by multiple bacteria working together.  It’s never just one.  “Studies have looked at biopsies of these lesions, to determine which families of bacteria are present, and found more than 20 different families of bacteria.  The ones that show up in an early lesion are different from the ones found later in the chronic lesions.  There are big changes in the bacterial populations as these lesions move from early to chronic,” Engelken says.

“We’ve always talked about Treponema as causing the disease, but what we find in early lesions are other bacteria and very little Treponema.  Those come in later and become the dominant ones in chronic cases.”  Other bacteria have to break down the tissue resistance and open the way.

Joe Cavanagh (a foot trimmer in Maryland) has trimmed cows’ feet for fifty years.  He has seen many foot problems but the first case of hairy wart he encountered was at a Farm in Quicksburg, Virginia in 1975.  “The 2-year-old cows had it so bad that their feet had grown abnormally and looked like a square block.  The owner was the first person I knew who used formaldehyde foot baths.  This has been the traditional strategy for treatment and prevention of hairy heel warts, but I haven’t used it or recommended it for the past 15 years because formaldehyde can cause cancer in humans,” Joe says.

Today, instead of using formaldehyde, he uses Kling-on Blue.  This is a patented formulation of copper sulfate, zinc sulfate, organic acids and a colloid binder created specifically for footbaths for cattle and sheep.  It forms a viscous solution that clings and hardens the hoof, leaving a film on the hooves after the animals leave the footbath.  For cattle it is used once a week until an improvement in hoof condition is seen.  “I got onto using this a couple years ago.  It comes in a 7-gallon bucket and is about the same thickness as paint. You pour it into the footbath and use a rake to stir it up.  It sticks on the feet and turns the feet blue,” he says.

Three years ago he started trimming feet for a farmer in Walkersville.  “It was a huge mess.  The first time I went there, the herdsman had 35 cows sorted out for me—15 sore ones, and 20 others to trim.  The first four hopped to the table three-legged.  One cow had hairy heel wart on a front foot that went from the heel up to the dewclaw, with a swollen area as big as a softball. Some of the lame cows had abscesses but most of them had hairy heel warts that went from the heel clear up to the dewclaw.  I wrapped every one of those,” Joe says.

“I told him he had to start foot baths, and that I needed to come once a week to work on those cows and get it under control.  At first the owner complained because of how much this stuff costs, but the herdsman told me it worked like magic.”