“Black Spot” – Derived from an article by Dr. J. Vanderborght (Belgium)
Black spot is caused by the circovirus, as outlined in an article by Dr. J. Vanderborght from Belgium. Most adult birds already possess a competent immune system when infected, allowing them to develop protective antibodies over a few weeks, ultimately clearing the body of the virus.
However, young chicks are highly susceptible during an outbreak, especially if the mother hasn’t generated sufficient protective antibodies to pass on to her eggs. As the hen hasn’t yet eliminated the virus, it replicates in the egg, compromising the immune system. Any secondary infection can then prove fatal to the newly hatched chick.
Stress is a significant threat to a healthy immune system, as it induces immune suppression. The breeding season’s onset often introduces stress to the breeding room. While immune stimulation measures are beneficial, they should be administered at low doses and intermittently.
Secondary infections can further weaken the immune system. While E. Coli is a natural inhabitant of birds’ intestinal flora, domesticated birds have been found to exhibit higher levels than their wild counterparts. These levels can be reduced through prebiotics, probiotics, and a robust hygiene protocol. Additionally, the addition of 5-10% egg yolk powder has demonstrated a reduction in E. Coli numbers, likely due to the protective antibodies it contains.
Black spot, in most cases, is not a disaster, unless there are massive outbreaks, which appear to be the exception rather than the rule. Currently, no vaccine is available. Understanding the disease is crucial for prevention and interpreting observed phenomena.
