The common pigeon illness symptoms changes should be sum up in three main points: digestive system, respiratory system and nervous system.
Various pigeon disease caused by the microbes, parasites the same as most common diseases, end up will have the same symptom as digestive system diseases.
It is not hard to find out the changes in appetite and drinking volume of the group. Excluding the quality and quantity change of belles and other sudden change factors, a decreased desire to eat is is a symptom that pigeon is getting ill. In most case, the results weight loss and loss of appetite are the main symptoms of pigeons and they are suffering an acute communicable disease. So if the appetite of the group are decreased suddenly, you should enhance the management and other features in case the disease goes further.
Another symptom of the pigeon disease is the changes of crop and mouth. You can carry out first-stage diagnosis of disease like Trichomoniasis, lack of Vitamin A, Candidiasis and other problems according the change of the mouth. You can find out pustulelike white spot in the mouth if the pigeon is lacking Vitamin A.
Other symptoms can be the alteration of the cloaca and intestinal flora.
Respiratory System
The respiratory system changes of pigeon disease should show up as the breaths rate and breath posture, breath sounds and so on.
Normal Pigeon breaths is about 16/s to 40/s, but when the pigeon is ill, breaths number will become higher than normal status. If bathes number is become lower, it means that the pigeon is dying or in coma.
Changes of ill pigeon breath posture is not really obvious and hard to indentify breath sounds will be much different than the normal status. An irritating rattle shows up the pigeon is getting ill, it sounds like other bird coughs. Unusual breath sounds always show up as the inflammation of throat, windpipe and alveoli filled with some foreign matter.
Nervous System
Symptoms changes of nervous system include three main points: mental condition changes, hypanakinesia and organum sensuum changes.