The Veterinary Medicines Directorate (VMD) is warning horse owners of the dangers of illegally imported veterinary medicines available on the Internet, at shows and through word of mouth.

Products in question include vaccines, wormers and antibiotics, most of which come from the Republic of Ireland, but also from the US and Australia, and are sold at a fraction of the retail price of authorised products. Some are copies of UK-authorised veterinary medicines, some are legal in their country of origin but not in the UK, and others are illegal in either.

“People buy them because of the price differential – legal products can cost as much as 70% more,” says Simon Hack, head of the enforcement team at the VMD, the body responsible for authorisation of veterinary medicines in the UK.

“But the cheap illegal products can do more damage than good – for instance, if the treatment doesn’t work, the vet comes, but he won’t know what has been administered and treatments can clash.”

The enforcement team at the VMD has been working to stamp out the practice for several years, and has brought a number of successful prosecutions. Those caught buying, selling or using illegal products face imprisonment or a fine of up to £5,000.

“Sellers have turned up on spec at shows with products in the back of a van. It’s a huge occupation for many people, but we are beginning to get a handle on what’s going on.

“Horse owners are starting to contact us when they’re offered anything suspicious.”

Products that have been through the authorisation process are marked with the letters Vm or PL followed by a five-digit code, an oblique and a four-digit code: for example Vm 04321/4000. Some European-authorised products, also legal in the UK, are marked with the prefix EU.

However, when buying over the Internet, it can be impossible to tell the difference between a bona fide product and an illegal import, because the buyer can only identify the authorisation code on receipt of the product.

The black market also inflicts considerable harm on legitimate manufacturers, who spend large amounts on having their medicines licensed.

Claire Williams of the British Equestrian Trade Association says: “We know it happens and it’s damaging to the industry. We warn our members about it and ensure that they can identify illegal wormers and other products.”

Anybody offered unauthorised veterinary medicines should contact Simon Hack or Barry Haycraft at the VMD (tel: 01932 338308).