Horse Health Care - Blister Beetle Threat

I received the following question a few days ago: “My friend was telling me that she read an article in a Horse Newspaper about beetles being poisonous to horses and that sometimes these beetles get into the hay where if the horses eat them, they will die. My friend couldn’t find the newspaper, so can you write about this?”

What your friend was referring to was a type of beetle called Blister Beetles. They are hard to identify as there are over 7,500 species. They are not so common in the Northern parts of the United States. There is an old wife’s tale about only spotted beetles can be blister beetles and this is not true. They can be red with black spots, or plain black or really any color. Do not rely on markings or color to identify Blister Beetles. They are pretty damn odd looking bugs, with a separate head, shoulders and body – although I doubt the technical body terms are correct. They do have three pairs of legs (6 legs total). Look at the pictures below and you’ll see what I mean.

I have only seen Beetles present in alfalfa maybe three times in the past 12-15 years. I threw out that bale, and was careful to pull apart and go through the other bales from that load, which came from the Dallas , Texas area. It did not keep me from contracting hay loads from the same transport or farm, but I always check my alfalfa, flake by flake when I feed, not only for Beetles but for mold and foreign contaminants. Heck, I have found turtles, rabbits, old shoes, paper bags, string, newspapers, beer and soda cans and a lot of other objects as well. So it just pays to check your hay.

What is dangerous to horses is that these Blister Beetles secrete a blister agent type of chemical called Cantharidin. Alive or dead these beetles can poison a horse with this chemical. It will blister the gut and cause pain and colic type symptoms, and there may be ulcer type sores in the mouth as the horses chew their hay, crush the beetles and release the toxin.

I am told the Blister Beetles feed off of the alfalfa flowers, which appear usually after the first cut. It only takes a horse to eat three or four of these beetles to kill it. So you can see that a very small amount of Cantharidin to be toxic and lethal.

I looked up the other symptoms and they may include frequent urination and dehydration. Treatment includes treating for colic; Some treatments include treating for colic; use of mineral oil to help move the poison through the gut more quickly and maybe to absorb some of the toxin and coat the lining of the gut; some people advise Charcoal may also be used to help absorb some of the toxin.

Consumption of Blister Beetles is life threatening for a horse you must take quick and effective action to save the horse, but it starts with checking your alfalfa and knowing what to look for. Safe Journey.

The Basics of Horse Nutrition: Understanding Hay

I don’t know how many times I have been asked questions such as…. “Just how hay do I need to feed my Horse?” …..”Could you look at my horse and tell me if I’m feeding enough?”….. I like these questions since it shows the horse owner wants to ensure he/she is taking care of their horse. I always remind these people that my answers are my opinion and if they asked several other people, they will get several different answers. The following opinion is for people who do not have their horses on pasture.

Generally, a horse currently in decent body condition needs 2% of his body weight in daily feed. That means a 1,000 lb horse needs 20 lbs of feed each day. And I’m talking hay here. There are two general types of hay: Grass Hay and Alfalfa. Grass Hay usually runs about 10—12% protein and Alfalfa Hay generally runs about 17 –23% protein depending upon what cut of the growing season it is.

Hay should make up the bulk of the horse’s daily feed. With the feeding of grains or processed and bagged horse feed, the daily requirements of hay can be reduced, however, again hay should make up the majority of the horse’s diet and most horse’s do well on hay alone providing it’s a good quality hay and must be free of mold. If it smells bad, don’t feed it!

Although thousands of horses do well on Alfalfa alone, the protein content can present problems that are somewhat avoided with a mix of grass and alfalfa or a grass only diet. There is a saying that everything a horse eats goes straight to their feet. That’s true but it goes the way of the gut and digestive tract before it gets to the feet. High levels of protein are thought to cause blockages or colic in the horse’s gut and can affect the hooves in negative manner such as leading to founder. Generally a horse that gets into grass hay storage and eats and eats and eats won’t have near the problems that the same horse would have if he got loose and overfed on alfalfa.

The more times you feed a horse a day, the better, however most horses do just fine on being fed twice a day. I feed my horses four times a day, dividing up grass and alfalfa in near equal amounts.

My reference bible on horse feed is Equine Clinical Nutrition, Feeding and Care, by Lon D. Lewis, DMV, PhD available from Amazon. I understand that this book is used as a textbook in some college equine management programs. It is worth the cost.