Another entry from Mark R. Baus, DVM, Fairfield Equine Associates, Newtown , CT 06470

My 12 year old mare has had three abscesses of the hoof in the last year. The vet noted on her most recent episode that "she has lots of separation of the white line of all 4 feet and I feel this is where the abscesses are coming from". He said this has the potential to be a chronic condition but not to worry myself too much at this point. He suggested short rounded trims and a hoof supplement. He said with good foot care and time (8 - 12 month's) the hoof wall should grow back and be ok. Is this sound advice or is there something else that would benefit and encourage hoof growth. She has been an incredibly sound horse up until this last year. Any suggestions or insights would be appreciated. Patricia in Indiana

Dear Patricia,

Since the separation of the white line is occurring in all four feet, I would guess that the abscesses have also occurred in more than one foot. Your veterinarian’s advice to care for this frustrating problem is certainly quite sound. I am concerned about two related possibilities that potentially explain the separation and the recurrent abscesses. I am concerned that your mare may have Equine Cushing's Syndrome and I would want to know if laminitis has subsequently occurred.

To arrive at a more definitive diagnosis, I would ask your veterinarian to perform two diagnostic procedures. Firstly I would ask for blood tests to determine your mare’s Cushing's status. Bear in mind that these tests are not as accurate when performed in late summer through the fall of the year. Secondly, I would ask your veterinarian if it would be appropriate to take radiographs to determine the true amount of hoof wall separation and whether laminitis has caused that separation.

Even if both Equine Cushing's Syndrome and laminitis have occurred, the signs may well be managed by paying close attention to hoof care and diet along with the supplements your veterinarian has recommended. With the additional information, you will be able to more confidently manage your mare’s long term health and soundness.

What do you recommend for horses who are prone (even with good preventive care) to rain rot? Rebecca

Dear Rebecca,

Rain rot, or dermatophilosis, is a frustrating skin condition because some horses just seem to get it each year no matter what you do. There are a number of reasons for this. First, Dermatophilus congolensis, the organism that causes rain rot, is “opportunistic.” That means it’s constantly in the environment, just waiting for conditions to be right so it can cause infection. The right conditions are a break in your horse’s skin AND enough moisture for it to grow. That’s why rain rot is most often seen during the wet season in whatever part of the country you live in and on the top parts of the horse (withers, saddle area, rump).

Experts think some horses have an inherited natural resistance to the organism. In other horses, it causes infection either because their skin is not healthy to begin with or the entire animal is debilitated, either from parasites, poor nutrition, another infection or cancer. Work with your veterinarian to make sure your horse is healthy inside and out to reduce his chances of another episode of rain rot this year. And don’t overlook the value of daily grooming or omega-3 fatty acids to keep his skin healthy.

I’m sure you’ve got your treatment regimen down: get the horse out of the wet environment, bathe him in povidone-iodine shampoo until healed, and remove the painful “paintbrush” crusts as they soften. To help prevent reinfection, make sure you keep the surroundings as scab-free as possible, so don’t just drop crusts into the stall or aisle. Also, use iodine to disinfect any tack or brushes that come into contact with the horse during an active infection. By following these tips, huge numbers of the organism won’t contaminate your barn and equipment.

Dear Dr. Gray,
    My 10 year old quarter horse developed hives about the size of a half dollar to a quarter ALL over his body.  He has never had hives before.  The other five horses on the farm do not have hives.  My vet put him on HistAll antihistamine at that time.  They went away in a week and then came back in two weeks.  I continued him on HistAll with minimal affect.  My vet pulled blood and sent it away to a lab in Arizona.  The allergy test came back that he is allergic to 17 things ranging from wool, at the top of the list, to willow trees.  We sprayed the field he is kept in for weeds and molds, which were six of the allergies.  We changed his hay to fescue because he is allergic to timothy, johnson, and orchard grass.  I have taken away all the possible things showing up on his allergy list.  However, we cannot keep him safe from the pollens and molds on the allergy list due to the weather and wind.  We have had him on flax seed meal, Spriolina, and BioZin with his grain and antihistamine with direction from my vet.
    The hives went away again in mid June for a week and then returned.  My vet gave my horse a shot of Dexamethasome (SP?) and capsules if needed.  The hives went away immediately, but returned five days later.  I started him on the capsules.  The hives went away after two days.  I stopped the capsules as told by my vet.  Five days later the hives started to return; I repeated the two days of capsules; hives gone.  I am waiting for the next five days to see what happens.  The hives return smaller and fewer each time.
    My vet suggests I start him on desensitizing shots prepared by the lab who tested him.  My vet says this process only has a 60% cure rate, but I should try.
    Is there another process or professional I can try?  We live in Fredericksburg, VA where it has been unusually hot and dry.  Many people are having hive trouble, but not this severe.  We moved here from southern VA 10 months ago, so I guess it is the region.
    HELP!  I would appreciate your opinions and suggestion.
        Thanks, S.S.

Dear S.S.,

Of all the skin conditions horses get, hives has to be one of the most difficult ones to deal with.  You almost need to be Sherlock Holmes to figure out what causes it!  On top of that, the medication regimen can be expensive and complicated and doesn’t always work or keep working.  And your poor horse looks and feels miserable.  You didn’t mention if yours was itchy as well as lumpy, but many are.

I like that you’re on products with omega-3 fatty acids, as research has shown they help maintain healthy skin and even improve certain skin conditions, like hives.  Until you can discover and remove the stimulus though, antihistamines and steroids will also be necessary.  You may want to ask your veterinarian if a different kind of antihistamine or steroid might work better in your individual horse.

Since your horse never had hives before you moved to this new area, it does sound like something in the new environment is causing this reaction.  The choices are many:  something in his diet, something he’s inhaling, something he’s coming in contact with, etc.  His hives could also be caused by a hypersensitivity to insects. 

You can either systematically eliminate potential causes one by one and wait to see if he gets better or you can attempt to diagnose the cause by testing.  Unfortunately, testing is controversial, as some feel the blood test your veterinarian has performed is not as useful as intradermal skin testing.  Before you start the desensitizing injections based on results of the blood test, talk to your veterinarian about the pros and cons of intradermal skin testing.  Or, ask him to help you get a second opinion at the nearest referral center, whether a private practice or University.

In the meantime, keep your horse as comfortable as possible.  Give frequent cool baths—with or without a soothing shampoo or other product—and protect him from insects with a fan in his stall and a mask, sheet and leggings during the day.

Please help me understand what laminitis (founder) is! It was devastating to watch a beautiful horse like Barbaro succumb to this disease last year, and frustrating to know that the best care in the world couldn’t prevent it. Didn’t Secretariat, another famous racehorse, also develop laminitis?  From: Curious

Laminitis can strike horses of any breed, age, and value, including multi-million dollar racing stallions like the two you mention. The National Animal Health Monitoring System (NAHMS) report for the year 2000 said 13% of all horse operations had a horse with laminitis in the previous year and 4.7% of these died or were euthanized. That makes laminitis second only to colic as a leading killer of horses.

To understand this disease, I'll review a little anatomy first. Inside the horse’s hoof is a bone called the coffin bone. It’s attached to the hoof by tiny interlocking fingers, or laminae. A complex cascade of events occurs during laminitis, but the key events are inflammation of these laminae (therefore the name laminitis), their death and the death of cells around them. When these tissues die, the coffin bone is no longer properly supported in the hoof. Then, forces from bearing weight on the ground as well as tendons pulling upward on the bone can cause it to rotate or sink in the hoof. When mechanical damage like this occurs, the horse is said to have “foundered.”

According to Rustin Moore, DVM, PhD, Dipl. ACVS, who shared his research at the most recent Bluegrass Laminitis Symposium held January 2007 in Louisville, KY, laminitis often occurs because of other conditions in the body, such as:

• Pasture (carbohydrate) overload
• Grain overload
• Colic
• Endotoxins in the blood
• Uterine infection or retained placenta
• Metabolic disturbances such as insulin resistance
• Excess weight-bearing on a supporting limb (opposite a limb with a severe injury)
• Infection of the blood (septicemia)
• Infection of the lungs
• Enterocolitis (inflammation of the small intestine and colon)

Diagnosing laminitis isn’t difficult, as most horses demonstrate very characteristic signs of the disease:

• Shifting of weight from foot to foot
• Slight stiffness of gait
• Reluctance to move
• Classic founder stance: all four feet forward, so hind feet carry more weight
• Warm feet and bounding digital pulse
• Sweating, high heart and respiratory rates
• Lying down and refusing to get up

The true challenge to laminitis is treating it. Because there are so many causes and such a complex cascade of events leading to its development, no one treatment works all of the time for every horse. Each case must be handled individually. The goal of treatment is to remove or treat the primary cause, stop the cascade of events, provide mechanical support to the foot, and of course, reduce the inflammation and pain. It us unclear why some horses respond to treatment more successfully than others but hopefully the ongoing research will provide some answers.

Hello! I have 2 young donkeys, a Jack and Jenny. They both have hoof problems and my farrier doesn't know what to do. Their hoofs are very soft, and they just seem to be flaking off from the outside from the bottom up about 1". I am pretty worried. Are there some supplements that would help them with this problem? There is not alot of info out there on Donkeys and how to feed them correctly. Any help would be appreciated.  Thanks, Sarah, Texas

Hi Sarah,

There are two ways to approach improving hoof quality: from the inside and from the outside. Research has shown that biotin—and other specific ingredients--can improve both the quality and the quantity of the equine hoof:

“Farrier’s Formula feed supplement was added to the diet of 18 horses with two types of hoof horn defects. The first group of horses showed sand cracks and crumbling horn around the nail holes; the second group suffered frequent bruising and had flat feet with collapsed heels. Hoof clippings from both groups were studied in the transmission and scanning electron microscopes. All the horses showed a progressive improvement in the gross and microscopic structure of the hoof horn, starting six weeks after the supplementation began. Once good quality hoof horn had grown there was no relapse during the two year period of the study.”

Vet Record. 1991 Feb 2:128(5):115-6.

If your donkeys already receive good-quality hay or pasture and a fortified grain, ration balancer or multi-vitamin/mineral to supply the rest of their daily nutrient requirements, adding a hoof supplement may be all you have to do to help improve their hoof quality. However, if they are only getting hay or pasture, then you may want to add one of these types of products to make sure there are no nutritional gaps that could be contributing to the problem.

To improve the quality of their hooves from the outside, make sure the environment is “hoof-friendly” and use products designed to help maintain the right moisture and oxygen content in the hoof.

A hoof-friendly environment is one that is as consistent as possible. That is, hooves are not going from wet to dry to wet conditions on a regular basis. Experts believe a constantly changing environment is worse than one that is too wet or too dry. So don’t give your donkeys baths unless you have to, don’t overfill the water tank so there’s mud around the outside, and don’t let their stalls become wet with urine and feces.

There have always been a lot of choices in topical hoof products, and it’s difficult to decide which, if any, your equine needs. Some experts say don’t use anything, some say avoid petroleum or tar-based products and only use lanolin-based ones, and some say use a hoof or sole toughener or sealant. I recommend asking your veterinarian and farrier what they suggest, then pick a product and try it for a while to see if you notice any improvement.