Introduction
Many species of coccidia have been found present in geese, both farmed and wild. It is a more severe problem in goslings, from between 3 - 12 weeks of age, in which mortality will occur frequently. Coccidia is frequently introduced into domestic flocks by migrating wild geese, which are resistant to the disease.
There are two strains Eimeria truncata and E. anseris, which are of most pathogenic importance, with the latter causing intestinal disease and E. truncata causing renal coccidiosis.
Clinical Signs
Renal Coccidiosis
Signs include severe depression such as reduced appetite and huddling, emaciation and diarrhoea. Mortality rates are high, however, birds that recover from the infection remain strongly resistant to it for life.
Intestinal Coccidiosis
Signs include depression, weakness and general malaise. Haemorrhagic diarrhoea is also seen. There are high morbidity rates within the flock, but mortality rates are not as high as with renal coccidiosis. The presence of concurrent infections would increase risk of mortality.
Diagnosis
History and clinical signs, along with a post mortem of a sick bird (which will have been sacrificed for this purpose) should lead to a presumptive diagnosis. In the case of renal coccidiosis, post mortem will reveal enlarged, pale grey coloured kidneys, with petechial haemorrhages on the capsule and tubules. Intestinal coccidiosis will have characteristic caseous core lesions on the intestines as well as them being enlarged and filled with a reddish brown fluid.
Examination of a sample of the effected area under a microscope should reveal the oocysts and confirm the diagnosis.
Treatment and Control
Control is based on good hygiene and husbandry such as good ventilation and trying to reduce the risk of wild geese contaminating the area.
Treatment, if required, is a dose of sulphonamides. Other anitcoccidial drugs should not be used as their safety in this species is unknown.
References
Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition) Merial
Jordan, F, Pattison, M, Alexander, D, Faragher, T (1999) Poultry Diseases (Fifth edition) W.B. Saunders
Saif, Y.M. (2008) Disease of Poultry (Twelfth edition) Blackwell Publishing