Question:  I recently built three 14' x 65' drylots for my horses.  The soil in my area is heavy, mucky clay.  What do you recommend using as footing to ensure proper drainage and as little mud as possible?

Response:  Unfortunately, with heavy clay soil, drainage and mud is going to be a continued problem unless the drylot is renovated.   The below system, called a high traffic pad, has proven to work (tested at the Universities of Kentucky and  Vermont) and will dramatically decrease mud problems in drylots.  To install a high traffic pad:

· Remove the 8" of top soil

· Install drainpipe to direct water out of the pen.  The pipe must be sloped towards an outlet. 

· Roll out geotextile fabric.  The fabric comes in large rolls. 

· Add 4" of crushed limestone (usually 1 ½ to 1 ¾ in diameter).

· Add second layer of geotextile fabric.

· Add 4" of dirty pea stone (small gravel)

· Refresh the top layer as needed; usually once every year or two.

 

The estimated cost for installing a high traffic pad is about $0.80 per square foot.  In one of your 14' x 65' drylots, the cost to renovate the entire paddock will cost just under $800.  To lessen the investment, renovate one  drylot per year. 

 

The University of Kentucky has a factsheet further outlining the process.  It is available online at www.ca.uky.edu/agc/pubs/id/id164/id164.pdf

 

By:  Krishona Martinson, PhD, University of Minnesota 

Q: I want to install wood fence posts around my horse paddock. Would you recommend using treated wood?

A: Wood posts are a common and safe option for horse paddocks. However, wood has natural enemies including insects, mold, fungi, and bacteria. Some species have natural resistances, such as, cedars, junipers, locust, and redwood. Treated wood is more expensive than un-treated lumber, however, it will help extend the life of your wood fence, likely more than paying for the additional expenses. Current chemical treatments include copper cremated copper arsenate (CCA), ammonical zinc copper arsenate (ACZA), copper amines (copper azole, CBA-A & CA-B; alkaline copper quat, ACQ-B, ACQ-C, ACQ-D), and copper naphthenate (CU-Nap).

Pressure treated wood should last 30 to 35 years in Minnesota, compared to untreated wood, which generally lasts between 7 and 15 years. In drier climates, some posts can last longer. For example, cedar posts in western South Dakota can last longer than 100 years. In wet soils, filling the bottom 6 to 12 inches of the hole with a builders grade sand will increase the life of the post. Setting posts in concrete is not recommended because of the expensive and difficultly in replacing or moving the post.

Although horses do commonly chew on wood, I am not aware of any health problems (not counting dental issues) related to horses chewing on treated wood. If a horse is known to crib or chew, CU-Nap treated wood is the best option as no known health risk have been determined if ingested (maybe difficult to find). Another option is to install a single strand of electrified barbless wire, which will help keep the horses from both pushing on the fence and chewing on the wood; further extending the life of the fence and reducing maintenance costs.

CCA and ACZA treated wood has limitations because of arsenic, and has been band in the residential construction market; but still can be purchased in the agricultural sector. If CCA or ACZA is used, recommendations are to not have the CCA treated wood come in direct contact with feed; not used for bunks (support legs are OK), feed storage boxes, etc. The arsenic treated wood is also not recommended for use in playground equipment.

By: Chuck Clanton, PhD, University of Minnesota

Q: When cooling a hot horse after exercise, many people simply spray the horse all over with water and do not scrape away the excess. Does it really offer a benefit to spray the entire body as opposed to just the legs and belly?

A: Spraying water on a hot horse to cool it off promotes convection cooling and assists the horse in lowering its core temperature. The reason you spray the legs and belly is because the blood vessels are closer to the skin in those locations and it promotes faster cooling of the horse's core temperature by carrying the cooler blood to the heart.

Another important part of cooling out horses is evaporation. After the horse has been sprayed off, it is very important to scrape the water off, because once the horse is sprayed, the water absorbs the horse's heat and becomes warm. In order for evaporation to occur effectively, this warm water must be removed. This process can be repeated until the horse's temperature comes down (i.e., spray, scrape, spray, scrape). If the water is not scraped off, it could act as an insulating layer, and actually make the horse hotter than when you started.

In extreme circumstances, ice can be added to water buckets to increase the speed of cooling the core temperature. It is commonly thought that ice will be a shock to the horse's system and could cause tying up (muscle cramping); however, with extreme heat and internal body temperatures, this is not the case.

If a horse is prone to tying up, it may be recommended to not directly apply the ice to the large gluteal muscles in the hind end, but focus on those key areas where the blood vessels are more superficial.

By Carey Williams, PhD, Rutgers University

Q: With winter coming, should I blanket my horse?

A: Blanketing a horse is necessary to reduce the effects of cold or inclement weather when:

1. there is no shelter available during turnout periods and the temperatures or wind chill is below 5°F;
2. there is a chance the horse will become wet (i.e. rain, ice, or freezing rain);
3. the horse has had its winter coat clipped;
4. the horse is very young or very old;
5. the horse has not been acclimated to the cold (i.e. relocated from a southern climate); and
6. the horse has a body condition score of 3 or less.

Keep in mind a horse will continue to develop a natural winter coat until late December; and blanketing before late December will decrease a horse's natural winter coat. Horses, given the opportunity to acclimate to cold temperature, often prefer and are better off outdoors.

By Marcia Hathaway, PhD, and Krishona Martinson, PhD, University of Minnesota

Q: I use rubber mats over a concrete floor in my box stalls. I use only enough sawdust to absorb the urine and moisture in the stall and clean it out completely each day. I have never seen a horse lay down in the stall. Is there any reason to add more bedding in the stalls?

A: Horses need to lie down in order to get an adequate amount of deep sleep and will eventually, over weeks or months, become sleep deprived if they cannot or will not lie down for some reason. Opinions vary, but research on the subject suggests that relatively hard ground doesn't usually deter horses from lying down and getting enough sleep. Wet ground and deep mud will be a significant deterrent, however, as will a slippery surface.

If it were only one of your horses that never seemed to lie down, I would worry about musculoskeletal or lameness pain playing a role. Older or arthritic horses, for example, tend not to lie down as much as they should and go on to suffer sleep deprivation. In those cases, treatment of the pain is very helpful. If none of your horses lie down while in the barn, it makes me wonder whether they prefer to lay down outdoors for some reason. If you are worried, it is certainly worth running an experiment by bedding them more deeply for a time and looking for any change in their sleeping behavior.

By Christie Ward, DVM, University of Minnesota

Q: Do you know if horses can get any diseases from deer? With the amount of snow we had this winter, the deer are eating hay out of the round bale feeder.

A: Unlike cattle and bison, which can contract tumberculoss (TB) from deer, horses seem to be less susceptible. I have never personally seen a case of TB in a horse in approximately 20 years as a practicing veterinarian. The risk exists, but is very low. There have been extremely rare reports of meningeal worm (Paralaphostrongylus tenuis); a parasite in deer feces that can migrate into the central nervous system of animals grazing contaminated pastures. Meningeal worm is a significant problem for sheep, goats, and camelids, but horses are minimally susceptible.

Some horse owners do prefer to fence the deer out of hay piles, which is basically impossible to do at a round bale feeder, unless horse access is also restricted. If the deer herd is large, fencing can reduce the economic impact of hay loss associate with deer feeding, which is likely of greater concern.

By Christie Ward, DVM, PhD, University of Minnesota

Q: There are small flying bugs that are turning horse manure into large areas of flattened mush. There are hundreds working on each pile. Do you know what they are?

A: Your "bugs" are actually small dung beetles or Aphodius haemorrhoidalis. We researched them in cow dung 15 years ago and found they were most abundant in spring, and tapered off in the fall. The ones you are seeing descended from a bountiful summer population and they are working on your horse's manure to build up nutrients for overwintering.

The beetles are actually beneficial; they spread out the manure, which speeds incorporation into the soil, and break up piles. It is possible that internal parasites eggs in the manure could become more spread out. However, any increase in parasite transmission would be minimal if you routinely deworm your horse(s).

By Roger Moon, PhD, University of Minnesota

Q: I'd like to purchase fly predators, but do they work? I have 5 horses on a dry lot over the winter and on pasture in the spring, summer, and early fall. I do spread my barn manure on 1 of the 3 pastures. I then drag it and let it sit for a month, and then rotate to another pasture. Can I get my fly population down with predators?

A: First, do you know what kind(s) of flies are bothering your horses? How do the horses respond when attacked by the flies? This fact sheet illustrates the main kinds of flies we have in Minnesota.

Fly Predators kill house flies and stable flies, but not other kinds of flies. House flies and stable flies develop as maggots in moist, decomposing organic matter, such as accumulated horse manure, soiled (wet) bedding, and spoiled feed (hay or grain).

I recommend people do the following to prevent flies from building up to annoying levels:

1. Dispose of accumulated waste in spring, so flies have little to develop in when weather warms in June.
2. From June thru September, spread manure daily, keep bedding dry, and keep feed from getting wet and decomposing.

If you do all these things, then you will keep house and stable flies from developing on your farm. Adding Fly Predators may not help much.

You might also ask if the flies bothering your horses could be coming from neighbors? Flies will travel a half-mile easily, and flies could be coming from other stables or livestock facilities. If your neighbors are a source, then all you can do on your place is spray residual insecticides to kill the adult flies. Source reduction would require your neighbors to improve their debris management, and maybe Fly Predators would be of help there.

By Roger Moon, PhD, University of Minnesota Livestock Entomologist

Q: I have an off the track thoroughbred who collapses periodically. I have had him since November and he has gone down twice in the cross ties and once by the mounting block. He is 8 years old and approximately 17 hands. I recreated the situation and discovered that if I tighten the girth he goes down. He has not done this with me riding him. I do not think this is behavioral. I am just looking for directions and answers.

A: Some horses develop this odd form of collapse when they elevate their heads or when the girth is tightened without it being a specific medical issue. Sometimes muscle soreness is involved. The collapse could also be a result of sore withers, ribs fractured, or fainting from cardiac issues. I would recommend a complete physical for the horse. During the physical, I would also recommend you tightening the girth while the veterinarian watches to see if there are other areas that need exploration.

By Stephanie Valberg, DVM, PhD, University of Minnesota

Q: I purchased a high frequency rodent controller (puts out high frequency sounds to deter mice, rats, etc...). I would like to know if it is safe to put in my horse barn? The box says it is safe for "pets", but does not mention horses. Will the high frequency harm my horses or "drive them crazy"?

A: We are not aware of any research that specifically addresses this issue. Have you contacted the manufacture of this product with your question? Horses do hear better than we (humans) do at high frequencies, but so do dogs and cats. If the manufacture says the product is safe for use around horses, we recommend trying the product further away from the horses at first, and then gradually moving it closer if the horses do not seem to react. We would encourage that while trying the product, someone is watching the horses and the horses have a way to evacuate the area. Finally, watch for any behavior or eating changes while using this product and stop using it immediately if you observe any adverse reactions.

By J. Wilson, DVM and E. Malone, DVM, University of Minnesota