COCCIDIOSIS
In young birds and adults under stress an acute form of the disease may be seen.
The organism affects the lining of the gut causing diarrhoea and blood may be present.
Affected birds are depressed, rapidly become emaciated and may die.
Keep a eye on your birds droppings Here’s a picture of a bird with digestion issues.
Here are some links that will help you.
http://www.Pigeonmad.com/pigeon_medication.php#COCCIDIOSIS_CANKER
http://www.Pigeonmad.com/pigeon_medication.php#COCCIDIOSIS