Ask Horse Journal: 01/00

Equine Narcolepsy
My mother’s horse has been falling down when she falls asleep. She sometimes acts lackadaisical or a bit strange. Mother doesn’t know if her mare is getting old or if there’s some other cause. She’s still great to trail ride and just has problems occasionally when mounting. Do you have any suggestions for this’

-Susan Henry

This sounds most like narcolepsy — a sleep/seizure disorder that makes the horse literally fall asleep at unpredictable times and be excessively sleepy or “dopey” at others. The falling down episodes are probably catalepsy, a rapid falling into deep sleep without warning that makes the horse (or person, or other animal) suddenly drop, muscles flaccid. Attacks may be triggered by excitement or eating but at other times have no obvious precipitating cause. The disorder is probably genetic, but genetics are not worked out and age at onset of symptoms is variable. It has been reported in many breeds but may be more common in cold/warm/half-bred horses. There is no good treatment. Nervous system stimulants have been tried with variable success and lots of side effects such as nervousness and irritability. There is a brand new drug available for people, Modafinil, which is said to have fewer side effects but it’s not clear if it is any more effective.

Less likely but definitely to be ruled out would be a cardiac arrhythmia. Older horses may develop heart rhythm disturbances. One that actually causes the horse to drop would be extremely rare but the possibility needs to be checked out. Also less likely would be an encephalitis of some sort or an encephalopathy of metabolic cause, like liver disease. The horse needs a thorough medical check up, probably by an internal medicine specialist.


White Spots
I just read your article about hair mineral analysis (September 1999). My 10-year-old gelding has hives and white spots, like your test horse. I did not understand exactly what to do about the possible aluminum toxic condition or what supplement would help this condition. My horse does not get any supplements and is fed pellets with pasture turn out all day.

-Barbara Dankworth
Ballinger, Texas

The first thing you have to do is determine if the problem is indeed due to a mineral deficiency. If your vet isn’t having any luck treating the problem and has ruled out allergies, take the analysis slip off your pellet bag and ask your vet, or local agricultural extension agent or an equine nutritionist if his diet is adequate (you will need to know the type of grasses in your pasture, too). Even if it checks out OK, you should probably get a hair mineral analysis done to pinpoint any deficiencies and find out exactly what they are. Some testing services (like Uckele) will give you specific recommendations regarding how much of what to supplement to correct your horse’s individual profile. We also advise you to evaluate the recommended supplements and your horse’s current diet with your own veterinarian or equine nutritionist.


Apple Cider and EPM
Is it true the more acidic/lower pH horse has an increased risk of falling prey to EPM protozoa (see “Controlling EPM From The Inside Out” July 1999)’ How about a horse with a lower temperature’

My six-year-old mare has had apple cider vinegar added to her feed since she was born. There’s a theory that doing so will decrease the chance of enteroliths — a big problem in Southern California with our alkaline soil and hay as well as hard water. The one cup she gets a day seems to make her unpopular with flies, too.

Her temperature has always been on the low side, around 97-98?°, and when I read that, “McLean found EPM horses . . . often register temperatures lower than normal” I got concerned. We board at a public stable of 112 horses — six or so have had EPM symptoms to the point where they don’t function well or were put down.

My horse is the picture of glowing health. In addition to a daily dewormer, she receives every day: 6 lbs. alfalfa (tested 18% protein); 6 lbs. bermuda grass (7% protein); 6 lbs. carrots (vitamin A) and 1 apple; 1 lb. alfalfa-oat pellets; 2 cups wheat bran (phosphorus); 1 cup apple cider vinegar; Grand Meadows Grand Vite Plus; Vitamin E 8000IU; Vitamin C; Magnesium 8 grams; NuSelect Coat Conditioner; Electrolytes (July-November).

I read an article in another magazine that says an acidosis condition in the horse leads to a rough coat, grouchiness and no appetite. Even worse, it said, is the “dire effect on the hind gut’s bacterial population,” which doesn’t survive in low pH environments, creating endotoxins that are “implicated in a number of serious outcomes, including laminitis and shock.” While my mare is anything but grouchy and is a real chubbette, I don’t want to give her something that would lower her resistance to EPM or predispose her to laminitis. Do you have any thoughts on how much apple cider vinegar could be safely fed to a horse without lowering her pH’ A friend in Utah says her vet says no more than three tablespoons of apple cider vinegar a day or the enamel on the horse’s teeth will be eaten off. I guess I’m lucky I don’t have a grouchy, rough-coated, laminitic, toothless scrawny mare with EPM!

-Micki Griffith
Harbor City, CA

The key to how healthful (or potentially harmful) a horse’s diet may be is to look at the overall balance. Your mare’s diet is a terrific example of how to build on an alfalfa base and balance the excess calcium with sources of additional magnesium and phosphorus. Many Californians would be horrified to hear you feed additional magnesium or wheat bran; they would think you are almost guaranteeing the mare will get enteroliths. You have probably avoided them because her diet is balanced.

As for feeding vinegar, how helpful or harmful any particular amount might be depends on your starting point. The abnormal intestinal alkalinity (high pH) found in the gut of horses with enteroliths has been attributed largely to low-grain diets, such as yours, although as you point out the alkalinity of the soil (and likely the water) also plays a role. One cup per day is within the range of recommended amounts for helping to prevent enteroliths under those conditions. As for it damaging tooth enamel, we have no direct information on that although you certainly are living proof it’s not necessarily true!

As for your other questions, intestinal acidity sufficient to cause shock and laminitis is something one would expect to see after something like grain overload — a horse getting free access to all the grain it could eat. Less pronounced acidosis can, over time, produce the clinical signs you mention. Feeding a cup of cider vinegar a day to a horse on a low grain diet is not likely to have this effect.

As for acidosis sufficient to potentially predispose the horse to EPM, this is a little more complicated. Local conditions in the intestines play a role to the extent that the integrity of the lining may not be normal but this also refers to a bodywide state of acidosis caused by environmental factors as well as intestinal conditions. This is combated by feeding the very same minerals in high or adequate concentrations in your horse’s diet (e.g. calcium and magnesium). However, you can confirm that your mare’s acid base status is normal by tests such as blood gas analysis, anion gap calculation, or even looking at the pH of a urine sample.

As for body temperature, each horse’s normal temperature will be individual. While lower body temperature in general could contribute to an increased risk of EPM surviving in the horse, if the horse is otherwise normal and has a healthy immune system this factor alone is not likely to determine whether or not the EPM organism can take hold.

More significant than ac tual temperature is whether or not the horse’s temperature shows wide swings from day to day, which could signal abnormal thyroid function and compromised immunity. If your mare’s temperature remains inside a narrow range when taken at the same time over several days’ readings, that is truly normal for her.


It’s Equine Cold And Flu Season, Too
A particularly nasty virus, probably a flu, with temperatures to 105?° is making the rounds in Southeastern Pennsylvania. Of course, young horses are the worst affected, but even old animals are showing a high incidence of less severe coughing and nasal discharge. Discharge changes from clear to white/yellow (indicating secondary bacterial infection) quickly, and a high percentage of the young horses have abnormal lung to go with their upper respiratory symptoms. The virus has spread rapidly between barns and among horses even without direct contact.

If you haven’t vaccinated yet, do it, but make sure none of the horses are ill before you do. (Vaccinating horses incubating a virus can precipitate a full-blown disease state.) Avoid any and all additional stresses, even to horses not showing symptoms, if cases begin to appear. Even routine dewormings may push the horse over the edge. Get your vet involved with high fevers or if discharges change from clear to colored.


Quick Test For Respiratory Tract Infection
Have you ever walked into your barn and heard a cough, but you weren’t sure who did it’ Most people’s first reaction is to grab a thermometer. While close temperature monitoring is a must, it won’t always alert you to irritation along the respiratory tract in time to avoid making it worse by exercise or other stresses.

The “tracheal pinch” test is a simple and reliable way to check for irritation. Locate the horse’s trachea high in the neck where it is superficial and you can get your hand around it. Using firm finger pressure, try to compress the trachea. A normal trachea is extremely firm/hard and will resist attempts at compression. Try this on a healthy horse so you know the difference before you need to use it.

With mild irritation, there is a distinct tissue softening, and you can compress it somewhat. Persistent efforts will usually induce a cough. With more advanced irritation, the trachea becomes extremely soft and even slight finger pressure will make the horse cough. The difference between an uninflamed trachea and one with even mild inflammation will be immediately obvious to you after you have practiced this just a few times.

Upper tracheal irritation correlates well with inflammation in the throat and possibly the bronchi but does not tell you to what degree the lungs are involved. Your vet will have to listen to the horse’s chest for that.


A Quick And Simple Halter Wrap
If you can’t find that “fuzzy” tube you use to prevent the halter from rubbing your horse on a trailer ride or when a halter needs to be in place for an extended time, don’t fret. Grab some cotton fleece or thick flannel (old sweatshirt works great), a pair of scissors and some tape. Cut the material in 1 1/2” wide strips and wind it around the top of the halter for an inexpensive, effective way to prevent halter rubs.

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