Hi Mark, some of the more common feed contaminants are:
- Horderine, is a naturally occurring plant alkaloid produced during the sprouting phase of barley, closely related to epinephrine, known commonly as “elephant juice.” Brewers grains, malt combings, distillers dried soluble, and sprouted barley may contain hordenine. There is no threshold allowance for hordenine and therefore it is advisable to avoid the inclusion of any of the above mentioned products in the diet of a performance horse. However, the FEI has recently increased the screening threshold for hordenine.
- Dimethyl sulfoxide (DMSO). DMSO is found in the urine of all horses and is believed to be almost entirely of dietary origin, most likely from lucerne (alfalfa) hay. As a drug, DMSO is used as a topical anti-inflammatory and analgesic agent. A threshold of 15.0 mg/l of urine or 1.0 mg/l of plasma is permitted.
- Morphine. Opiates such as morphine can cause central nervous system stimulation in horses. Morphine occurs naturally in a number of pasture species and in poppy seed, which is used in certain bakery products. Codeine and heroin is metabolised to morphine and are other potential sources of contamination in horses. Poppies grow wild in many countries and their prevalence depends on seasonal and geographic considerations, so you should carefully check your oats for presence of poppy seeds and seek veterinary advice if you see them. There is no threshold for morphine.
- Feed bin or environmental contamination. Several positive swabs have resulted from contamination of the feed bin or stable environment with banned substances such as isoxsuprine. In some cases, treatment of the previous stall occupant has led to a positive swab in a subsequent occupant, weeks after the first horse was treated. Another avenue for a positive swab is contamination of the horse's feed by residue from a handler's illegal drug use. Residue of cocaine use on the hands of someone who mixes the feed may lead to a positive swab.
It is the responsibility of riders, trainers, and veterinarians to be aware of the regulations relating to their particular area of equine sport. More importantly, it is the responsibility of the riders and trainers to ensure that they do not feed, inject, or apply anything to their horses that may contravene these rules. Ignorance is not a legitimate plea against a positive drug test.
If you use ACP to sedate a horse to clip, or bute to assist with a slight swelling, check with your vet how long traces will show up in the horse’s bloodstream. It is probable that, if you sedate the horse on Monday, it would test positive if competed on the Saturday. However, this is a very inexact science.
Check that all the feeds and supplements you are using are certified free of prohibited substances, and be careful around feeds. For example, you could eat a bun covered in poppy seeds over the feed bucket, and then find your horse tests positive for opiate.
Also caffeine, is a methylxanthine alkaloid and is widely distributed in nature. The xanthine alkaloids also include theophylline (from tea) and theobromine (from chocolate). In addition to these sources, many of the so-called “natural” products on the market also contain xanthine alkaloids. Guarana is actually 60% caffeine and is commonly sold as an energy-uplifting product. Administration of products containing guarana extract would likely result in a positive swab. Methylxanthine compounds are mild stimulants, bronchodilators, and vasodilators.
There are banned substances that have been deemed by the FEI to have no legitimate use in equine medicine and/or have a high potential for abuse (e.g., human antidepressants, antipsychotics, nervous system stimulants, etc.). These simply should not be found in any horse at any level at any time.
Hey Mark,the official list of prohibited substances is on the FEI website! You can check if you're not sure!
There are a lot of banished products like sedative products, hormones, analgesic, anxiolytics, etc.