Almost all diseases are introduced into a flock through the introduction of diseased animals. Diseased animals are inadvertently introduced through lack of professional skills to detect subclinical disease or due to a lack of affordable diagnostic tests. Prior to any introduction, make certain that the animals you are purchasing come from a healthy flock. This can be ascertained by a thorough health examination, serological testing, and health records of the flock of origin. Always require documentation of health records. Prior to introducing new animals into the flock, establish a quarantine facility adequately separated from the flock. The new animals should be observed for a minimum of 30 days. If there are conditions that need treatment or testing for disease, these can be conducted while the animals are in quarantine.
An example of introducing disease: While working with sheep in Kosovo, a diagnosis was made of ringworm, a fungal infection of the skin. The disease had never been seen in the region prior to the introduction of a group of breeding rams from Kazakhstan. Contagious Ovine Foot Rot is a prime example of a purchased disease that requires close examination. A 30 45 day quarantine, including a zinc sulfate foot soak, must be intensively managed prior to introducing these sheep into the flock. Ovine progressive pneumonia (OPP) is a more subtle disease with no apparent clinical signs early in the course of the disease. The animals should have a negative serological test prior to entry and another negative test while in quarantine. Provide strict biosecurity between the quarantine facility and the existing flock, including separate boots and equipment. Always attend to the quarantine facility last in the daily routine. The diseases will vary with the specific locality, but the measures to prevent introduction of disease are generally the same.
Genetics may predispose individual animals to certain health problems, which may spread with time if poorly managed. Scrapie is a degenerative disease of the nervous system; specific genes have been identified that play a role in this disease. Through testing and selection of QR and RR breeding stock this can be managed. Breeding stock should also be serologically tested for Spider Lamb, a genetic skeletal deformation in the lamb, requiring euthanasia. Entropion, an inversion of the eyelid, left untreated could lead to corneal ulceration of the eye. The management of this disease includes identification and treatment early in the animals' life, not breeding these animals, and culling the dams from which they come. The tendency for rectal and/or vaginal prolapse has a genetic link as well as management causes (docking tails too short, poor nutrition and environment).
Was this article helpful?