Medicated grit has become an important part of intensive grouse moor management to tackle parasite and disease issues arising from artificially inflated grouse populations. By providing grit containing veterinary medication, grouse moors aim to reduce the chances of game birds being badly affected by disease, ensuring more grouse breed to be shot and mitigating the consequences of intensive management.
The use of medicated grit is regulated by the Veterinary Medicines Regulations 2013, which outline safety standards which must be met for wildlife and environmental protection. These regulations specify medicated grit must be administered under supervision by a veterinarian or qualified individual and dosage based on worm counts. However, it remains unclear how effectively these regulations are enforced by the Veterinary Medicines Directorate on grouse moors.
With medicated grit being an important part of intensive grouse moor management, there are concerns about the widespread and unmonitored use of veterinary medicines on open moorland. The potential impact on wildlife and the environment raises alarm. Worryingly, a review of the scientific literature on the environmental impacts of grouse moor management noted concern that the widespread use of medicated grit may be leading to resistance to the prescribed drugs and emergence of new diseases among grouse populations. Medicating grit stations may serve as breeding grounds for respiratory diseases like cryptosporidiosis (also known as ‘Bulgy Eye’), resulting in sickly grouse with swollen eyes, lesions and breeding difficulties.
There is also evidence to suggest that Flubendazole, the active ingredient in medicated grit, can harm invertebrates, vital food sources for vulnerable breeding birds, and the risk of contamination in aquatic and terrestrial environments. To this effect, preliminary research by ecologists at the University of Leeds into the environmental impact of medicated grit found: “…soil samples spread across three different grouse moors contained concentrations…of the same order of magnitude as peak concentrations of veterinary medicines found in agricultural soils following manure application. These agricultural concentrations are significant enough to have driven the development of policy to better manage the presence of veterinary medicines in the environment.”