b. Paratyphoid is a common infectious disease of pigeons and is probably the most devastating of bacterial infectious diseases at the present time. It may affect the bird in many ways, and produce such a variety of symptoms that it is often mistaken for numerous other diseases. The only definite way of diagnosing paratyphoid is by laboratory tests. A tentative diagnosis can be made, however, upon observing typical symptoms.
(1) Symptoms. The course of the disease varies from a rapidly fatal blood poisoning to a slow, chronic disease with, or without, complete recovery. The infection may take place through the egg, by way of milk fed to youngsters, or by contaminated feed, water, and grit. The manner of infection has no bearing on the course of the disease. The germs may get into the blood-stream, go all through the body, and cause sudden death; or the infection may be less severe and localize in any one of the numerous organs.
(a) Bacteria may localize in the intestines and produce mild to very severe inflammation. This usually results in diarrhea.
(b) Localizations in the lungs are very common and appear as hard, dried abscesses. These are seldom so serious as to cause respiratory distress.
(c) Joint boils result from direct localization of the germs in the joints of the legs or wings. Naturally this produces lameness.
(d) Inflammatory reactions of the spleen and liver are often the result of the localization of the germ in these organs. Chronic inflammation of the entire liver is also observed. The abdomen of such birds usually fills with fluid and the bird then gets thin and dies.
(e) Paratyphoid germs quite often localize in the brain and cause abscess formation. Such abscesses cause a variety of symptoms, depending on which part of the brain is involved. Usually the bird shows loss of equilibrium. It may twist its head and neck about, show trembling of the head and neck, or other nervous symptoms. Such birds rarely recover.
(f) Occasionally the germ will localize in the eye. The inside of the eye turns white and sight is lost. Only rarely are both eyes involved. Such birds appear to be very ill and usually die in a short period of time.
(g) Germs may localize in the ovary of the female or testes of the male. Such birds may show no symptoms, or they may become sterile. Eggs laid by such birds may be infertile. Youngsters, if hatched, may be weak and die soon after. Germs may localize in the oviduct and cause an impacted oviduct.