Public demand is moving animal-based production toward organic systems. The standards required to allow an organic label for sheep products, although allegedly making the product safer for the consumer, do not tend to promote animal health. They prohibit the use of antibiotics, chemotherapeutics, and parasiticides (“chemicals”); therefore, organic producers cannot use preventive or therapeutic medications and rather must rely on “natural” or home remedies with questionable effects but no withdrawal times. This forces them to manage for disease prevention rather than use labeled medicines with known withdrawal times. These standards are often aspirational rather than practical and can lead to health issues and welfare concerns in organic flocks, even those that have excellent management systems dedicated to this approach. Veterinarians can be extremely helpful in this type of production system.
Organic flocks should be established from known health-status flocks that are free of testable and eradicable diseases such as orf/sore mouth, Corynebacterium pseudotuberculosis (cheesy gland, caseous lymphadenitis), Brucella ovis (ram epididymitis), footrot, maedi/ovine progressive pneumonia, scrapie, Johne disease, and chlamydial and Campylobacter abortion. Flocks should be maintained as closed flocks as much as practical, and new genetic stock should be sourced from known health-status flocks. New stock must be quarantined and thoroughly examined and tested before introduction to the flock and its pastures. Preventing entry of disease is critical, necessitating a high degree of biosecurity.
Parasitic gastroenteritis can be of particular concern in organic sheep production. In addition, although the regulations of some countries allow judicious use of anthelmintics and antiparasiticides, others do not. Management plans must include methods to avoid or reduce parasitic larval intake. Grazing crop aftermaths, using mixed species rotational grazing, attention to stocking rates, drylotting, and using pastures for hay and grazing only after a good freeze for a season, can all be used to limit internal parasites. Other strategies that have been suggested include grazing plants that may reduce GI parasitism such as chicory, sanfoin, birdsfoot trefoil, and the use of copper oxide needles. Breeding and selecting for genetic resistance is definitely a viable option and not too difficult using the help of individual fecal egg counts.
Last full review/revision January 2015 by Marie S. Bulgin, DVM, MBA, DACVM