Disease is spread by direct contact or indirectly, e.g. through infected grooming equipment and [[Biting Flies|biting flies]]. Once established in a population it is very difficult to eradicate, which is not helped by the long incubation period. New cases can develop weeks or months after the infection appears to have been eradicated. | Disease is spread by direct contact or indirectly, e.g. through infected grooming equipment and [[Biting Flies|biting flies]]. Once established in a population it is very difficult to eradicate, which is not helped by the long incubation period. New cases can develop weeks or months after the infection appears to have been eradicated. |