Clostridiosis as the cause of deaths in hand-reared parrot chicks.

Abstract A parrot breeder reported a problem with hand-reared chicks’ deaths. Pale skin and mucous membranes, sometimes convulsions, growth retardation and diarrhoea were observed in these birds. Post-mortem examination showed changes in the liver in two chicks, paleness or mottling of the kidneys, dilation of the proventriculus and gizzard, and bloating of the intestines in some birds. Microscopic examination of stained preparations from the intestinal content showed the presence of numerous spore-forming bacilli. Histopathological examination revealed degenerative and necrotic hepatocytes, lymphocyte depletion of spleen, bursa of Fabricius, and thymus and damage to the intestinal mucosa. Microbiological and direct molecular investigation of intestinal specimens showed the presence of Clostridium saudiense/Clostridium disporicum, in most samples tested, and Clostridium perfringens in one parrot. However, our study demonstrated that protein extract-based MALDI-TOF spectra, along with 16S rDNA sequencing, although commonly used for the reliable identification of many bacterial species, were not effective in distinguishing between C. saudiense and C. disporicum. Although the isolated clostridia, excluding C. perfringens, are not obligatory pathogenic bacteria, and they are a part of the intestinal microbiota in mammals.