A Disease Description

Editors note: I noticed the following when vaccinating my young birds. It is a short and accurate description of the disease and wanted to include it on this site so that it would be readily available for those using the search feature on this site.

Paratyphoid (Salmonellosis) in pigeons is an acute or chronic bacterial disease caused by Salmonella. The most common species identified in cases of paratyphiod in pigeons is Salmonella typhimurium. ( Murium is Latin for mouse)

The primary means of infection is through fecal contamination of feed, water or the environment( by rodents). The devastating nature of this disease is impacted by the occurrence of asymptomatic carrier birds which show no signs of illness and spread the disease to other birds. The organism may localize in the gallbladder or intestine and may then intermittently be shed through the feces.

Clinical manifestation of paratyphiod is broad in its range of symptoms. Of the several forms of expression, the disease in squabs (nestling pigeons) causes high mortality. Symptoms are usually evident soon after hatching and appear as retarded growth, diarrhea and death. Necropsy often reveals an unabsorbed yolk sac in addition to typical intestinal lesions. The squabs which survive the initial infection may develop swollen wing joints which prevent them from flying.

Adult birds may only show a mild infection or be completely without symptoms. Hens often develop infected ovaries and reproductive tracts leading to transovarion transmission of the Salmonella to the developing embryo and newly hatched chicks.

An articular form of the disease usually develops through a chronic course and involves the joints of the wings and legs. Dropped wings or leg lameness are clinically visible in this form. Another characteristic sign is apparent as joint swellings or "wing boils". The swelling is due to a collection of gelatinous exudate in the joint capsule. The Salmonella organism can readily be cultured from this exudate.

A septicemic form may be acute or chronic in course and clinically appears as depression, poor performance, weakness and watery, muciod diarrhea which leads to dehydration. Any stressful conditions exacerbate these symptoms. Other symptoms may be evident in the form of respiratory distress, anemia, or torticollis, a neuromotor defect due to encephalitis or inner ear infection causing the head and neck to be twisted to the side or extended over the back. Septicemia often causes an acute, severe enteritis with diarrhea and emaciation. Peracute deaths may occur as well.