Circo viruses are only descibed in pigeons since last year in Europe. The disease only occurs in youngsters from six weeks to one year old. The age of four months appears to be the most sensitive.
There is no seasonality like the classic example adenovirosis.
The mortality in nestlings and recently weaned pups up to 8 weeks of age up to 100. Sometimes the death is minimal and it occurs after three to four days after the onset of symptoms.
It is clear that the circovirus frequently occurs in young birds. How the infection exactly expires is not known . There may be a contamination by manure. For example in the travel baskets. It is thought that the virus suppresses the resistance (imunosuppressie). This is still unproven. Often this virus is demonstrated when other diseases are present. It is therefore questionable whether the abnormalities found post mortem are to be allotted to the virus or the accompanying diseases.The accompanying diseases areoften responsible for mortality. Probably the disease can be associated with poor general condition of the birds and mortality in nestlings. This is because the virus replication takes place in the organs of the defense system.The result is that the immunety is deficit and there are no good reactions to vaccinations . Possible that many young have an asymptomatic infection. If the infection occurs later in life than the consequences of the contamination is limited.
In section often only a pale or swollen spleen is found, semi-liquid green stool green and a green colored stomach contents. In the bursa of Fabricius inclusions are found.
The diagnosis will be based on the histological detection of inclusions in the bursa. Virus isolation is not yet implemented. In connection with the impairment of the immune organ it may be important to keep the defense of the older animals as high as possible. Bony SGR contributes to an increase in overall resistance. 5 ml per liter of drinking water. Several days a week.