Question: When we went to buy my new horse a salt block there were so many choices! I was told the brown one was best, then a customer in the store told me to buy the red one, so I didn’t buy anything! And they have blue and white ones too!! Help! Are the colors poisonous?
Answer from April Reeves: In my opinion, the perfect salt block for horses does not exist yet (hint to equine feed manufacturers – form one from sea salt please).
Red salt blocks: contain iodine – choice of horse owners. Same as our table salt (iodized).
Blue: contains iodine and cobalt – while there is no hard evidence that cobalt is bad or toxic for horses, many owners leave the blue behind for the cattle owners. Horses need cobalt in their diets – about <0.05 ppm. It is incorporated into vitamin B12, by the microorganisms in the cecum and colon and is an essential nutrient only if sources of B12 do not exist in the horse’s diet (Merck Veterinary manual: http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/182602.htm).
White salt blocks: contain nothing but plain salt (sodium chloride).
Brown blocks: these vary according to the manufacturer (read label). Generally, they contain selenium, and are more of a mineral block. I use them in conjunction with a regular iodine salt block.
I have heard that some people will not feed a colored block as the colors are from dyes. While I am not comfortable eating dyes myself, there are no studies for horses that have died from dyes, and personally, horses do not live long enough to accumulate such small quantities of contaminants like a human would. I still want to see that white sea salt block one day though (hint hint).
I have never heard of any study or research about any horse dying from incorrect salt intake, just from lack of salt (where they eat dirt and sand and die from sand colic instead). If anyone out there has valid information I would love to hear it. I have heard of horses not cleaning up their feed because owner’s add too much salt in it. Horses are smarter than we give them credit for, and will adjust their feed imbalances as they feel appropriate.
I let my horses take in the salt levels they require, by themselves (I do not add it to feed). None of the horses are stalled daily, and they do not chew their blocks in boredom.
The next time you go to a store, ask the people who work there for advice. Try not to walk out without a salt block; it’s your horse that will pay the price.