Ask Horse Journal: 09/02

Visiting-Deer Disease
re deer a problem if they mingle with my horses’ I know Lyme disease is a concern from the ticks, but should I be concerned about anything else’ Are there any symptoms I should worry about’ I vaccinate my horses annually for rabies because of the number of possums, skunks and raccoons that run in and out of the fields and barn, but the deer worry me.

-J. McNamara

Most of the internal and external parasites of deer, as well as their diseases, are far more likely to be transmitted to other ruminants, like cows or goats, than to a horse.?? However, there are exceptions.??

Lyme disease, as you mentioned, is one.?? Other tick-borne organisms like Ehrlichia and possibly some protozoa are another. Deer may also carry Listeria organisms.

Deer are a common sight to most of us and when simply passing through your pastures on their daily rounds aren’t really as much of a health threat as the birds that may be harboring West Nile, or the opossums that could be dropping EPM organisms.?? Except for the Listeria, which is found in the urine, the threat actually comes from infected ticks harboring organisms rather than the deer themselves so your best protection is tick control rather than deer control, i.e. remove bushes/scrub, keep horses out of wooded areas, avoid high grasses, use of repellants and regular checks for ticks.??It’s also a good idea to avoid having anything in the area that might tempt the deer to hang around, such as salt licks or feeders out in the fields or ponds.


Mixing Supplements
In the July 2002 prepackaged supplements article, you say “there could be a problem with interaction if certain supplements are stored mixed together for even a short period of time,” and “prepackaging eliminates the problem of open tubs of supplements losing their potency when exposed to oxygen and moisture.”

Several people at my barn mix their supplements into serving sizes in plastic sandwich bags.??I’ve often wondered if we’re actually doing a disservice to our horses, or wasting the effort and expense of feeding the supplement by reducing or eliminating its effectiveness, by mixing them. I realize you can’t list every supplement and every possible mix, but could you expand on this’

-Mary Ehrenberger

As a general rule, vitamins are more fragile and subject to damage from light and exposure to air than minerals so it is a good idea to supplement them separately. ??There are “protected” forms of vitamins available that are less likely to degenerate, but you have no way of knowing if the manufacture used them, so it’s best to buy these supplements separately.

Inorganic iron sources, such as iron sulfate, and iron contaminating other commonly used minerals like calcium phosphate or diphosphate, can react with antioxidant vitamins, especially E and C. ??Ideally, these would not be mixed and stored together although we can’t give you a precise time frame for how long it would take the interactions to occur. It depends on things like temperature, level of iron — which you won’t find listed on the bag, even if there is a guaranteed analysis since the level given will only be “minimum” or “extra added iron” — exposure to light and oxygen. ??Protected forms of vitamin E will retain their potency in mixtures with minerals for about three months, unprotected forms for far less. Feeding high levels of fat at the same time as minerals can decrease absorption, especially of magnesium.


Rhino Vaccine Use
As a person with a background as a veterinary/medical technician and longtime horse person, I am constantly asked questions about what to do for problems that come up in horses of my friends. Much of my most current information comes from Horse Journal. Your publication is hugely helpful, and it never fails to answers questions I hear or see via e-mail and Internet chat groups during a month. You will cover many of those same subjects in the next month’s issue. I read the sidebars first, they are guaranteed to be chock full of helpful practical information.

In light of the article in the July 2002 issue about neurological rhino, my question has to do with the common practice of vaccinating all the horses on a farm for rhino if there are mares in foal or foals present on the property. It is not often an option if boarding on such a facility. On my own, I don’t vaccinate for rhino. When boarding where there are mares and foals I have gone with the flow, but is this a necessary practice if you are vaccinating the mares themselves for rhino’

-Patricia Orgas

First, it’s important to realize that rhino vaccination does not protect mares from rhino-induced abortion.??It does reduce shedding, though, and??is used as a management strategy for helping to reduce the amount of virus circulating on farms where there are pregnant mares.?? If the virus load is kept down, the chances of abortion are lessened.

Adult horses don’t need rhino vaccinations. Most adults are asymptomatic carriers anyway and can handle exposure to rhino viruses without developing any symptoms.?? In fact, many experts feel that the vaccination of adults for rhino may put them at a higher risk of developing the neurological form of the disease since this seems to have a strong antibody-mediated component.

If you can find it, the best boarding situation for an adult horse is a facility that has neither pregnant mares or young horses.?? Your horse’s rhino exposure under those circumstances will be minimal and you will not have to vaccinate only for the sake of other animals on the farm.


Horse Needs To Gain Weight
My vet suggested adding one-quarter cup corn oil to my horse’s grain in an effort to add weight. However, she won’t eat her grain with corn oil. You’ve mentioned CocoSoya oil. Could this be used as an additive for weight gain and, if so, where can I purchase it’ What else could I use for weight gain’

-Susan Gannon

Yes, CocoSoya oil (, 800/248-0330) has the same calorie content as corn oil, plus the added benefits of being unprocessed and containing natural vitamin E and other antioxidants.?? Most horses find it palatable.

If you haven’t already done so, you should also have your horse’s teeth checked and have a fecal examination done for parasites.?? Be picky about the quality of your hay and grain.?? Improving the efficiency offiber digestion by supporting the microorganisms in the large bowel also often leads to weight gain.?? We would recommend Ration Plus ( 800/728-4667).??

In addition, rolling, crimping, cracking, steaming of grain improves digestibility, especially if the horse doesn’t or can’t chew it properly.?? You might also try an extruded senior feed as the “cooking” also improves digestibility.


Feeding Supplements Without Grain
I don’t feed my horses grain, and I don’t like bran because I’m worried it will cause mineral imbalances and cause digestive problems. Is there anything better to mix supplements in that isn’t fattening and won’t bother digestion and won’t cause any other problems’ I prefer to mix it with water as it carries the supplements better if it is wet.

-Lee Lattin

A good option for your situation is beet pulp, which doesn’t have a perfect mineral profile, but you would need so little of it that the impact is negligible.??A cup of dried beet pulp can soak up as much as two to three cups of water to create a substantial volume of feed as a carrier for your supplements.??It’s well and easily digested, well tolerated by horses with tou chy intestinal tracts and palatable to most horses. Shredded carrots, carrot juice or applesauce can be added to tempt the finicky.

Another option is to use hay cubes or pellets, alfalfa being especially well accepted. Again, it again takes such a small volume to get the job done that the alfalfa mineral profile is not a major concern.?? Both hay cubes and pellets will fall apart when soaked to form a “mash” consistency.


Allergies And COPD
I have a rescued Tennessee Walker who is COPD (heaves) and who breaks out in welts also. Is there a plant-based source of B vitamins’

-Gayle G. Schroeder
South Carolina

The best natural source of B vitamins is brewer’s yeast.?? The levels aren’t particularly high, though, and feeding large amounts can cause digestive upset.?? Bs alone also aren’t likely to help these conditions too much. We’d try Vita-Key’s Antioxidant Concentrate (, 800/539-8482), which will give you both good levels of Bs and other antioxidants, or HorseTech’s Nutra-Flax (, 800/831-3309) for vitamin and mineral supplementation plus the benefit of the anti-inflammatory omega-3 fatty acids from the flax seed.

In addition, magnesium has been found to be helpful for human asthmatics, so you may want to try adding enough magnesium to get the horse’s Ca:Mg ratio in the diet to about 2:1.


Autumn Health Awareness
??? Toxic Plants: As pasture quality and palatability drops off, horses will be less picky about what they will eat. Watch for odd-growing plants that seem to become dominant as grasses wane. Supplement hay to help prevent accidental ingestion of a bad plant.

??? Founder Watch: Freezing overnight temperatures can trigger grasses to produce high levels of sugars that may bring on an attack of laminitis in some horses (see July 2002). Limit grazing during these times for high-risk horses.

??? Bug Patrol: Fall is also a time to watch for biting-insect-transmitted diseases. If you’re in a high-risk area for encephalitis viruses and your horse was vaccinated in early spring, a fall booster shot may be wise.

??? Deworm For Bots: Your horse has been picking up bot larvae for several months by the time it’s fall, many of which are already large and damaging the stomach lining. We’d deworm for bots in the fall now and again in the winter.

??? Breeding Farms: Schedule any necessary trimming, deworming, vaccination for at least three weeks in advance of weaning and check the areas weanlings will be using carefully for injury hazards and fencing weaknesses. For pregnant broodmares, keep an eye on that calendar so that you don’t miss the five-month mark if you are going to use bimonthly rhino vaccines.


Vinegar For Weeds
Many owners worry, justifiably, about using herbicides in pastures their horses graze. In July, the Agricultural Research Station of the USDA released a study using a readily available and safe/organic substance for weed killing — vinegar. Saturating young weed plants with a 5% solution of vinegar reliably kills them. Older plants may need up to a 20% solution. One of the toughest weeds to eliminate from pastures, thistle, was actually the most sensitive. A 5% solution will kill even older plants. A 20% solution kills them in two hours. The 5% solution is what you buy in the grocery store. The 20% vinegar is available at organic gardening suppliers or feed stores. Note: Concentrations over 5% can irritate or damage the eyes. Do not use concentrated vinegar as a fly repellent on horses. Protect your skin and eyes when spraying weeds.


Let ‘Em Run
It’s well known that foals on full turnout have improved tendon strength compared to total or partial stall confinement. Now, a study from the Netherlands shows similar results for articular cartilage. After a foal is born, his joint cartilage undergoes several changes that allow it to withstand the forces it must undergo. In foals allowed to move around normally, the process is complete by five months. However, it’s delayed in foals deprived of exercise.

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