Systemic Histomoniasis in a Leucistic Indian Peafowl (Pavo cristatus) from Southern Brazil

Abstract

The pathological and molecular findings associated with Histomonas meleagridis are described in a leucistic Indian peafowl (Pavo cristatus) from Southern Brazil. The most significant gross findings were multifocal necrotizing hepatitis and diphtheric typhlitis. Histopathologic evaluation of the liver, ceca, kidney, spleen, and small intestine revealed systemic histomoniasis (SH) associated with intralesional and intravascular accumulations of histomonad organisms consistent with H. meleagridis. PCR was used to amplify the DNA of H. meleagridis from the liver, ceca, small intestine, spleen, lungs, and kidneys. Direct sequencing and phylogenetic analyses confirmed that the isolate of the flagellated trichomonad identified from this investigation is more phylogenetically related to H. meleagridis than Tetratrichomonas gallinarum, Tritrichomonas foetus, and Dientamoeba fragilis. These results confirmed the occurrence of SH in this peafowl and add to the diagnosis of this disease in birds from Brazil. This report might represent the first complete identification of spontaneous histomoniasis in a peafowl due to pathological and molecular characteristics and one of the few documented cases of SH in non-commercial birds.

Infecção natural por Histomonas meleagridis em pavões-indianos (Pavo cristatus)

“…A histomoníase afeta diversas espécies de aves domésticas e silvestres [1,14,15,23,24]. Dentre as espécies afetadas, os perus são os que apresentam maior morbidade e mortalidade [7,14], entretanto também pode acometer galinhas [1], perdizes chukar [18], faisões e pavões [17,24].…”

“…Além do ceco e do fígado, ocasionalmente pode haver parasitismo de forma sistêmica, tendo relatos de lesões nos rins, pulmões, baço e bolsa cloacal [4,17,22] o que não foi observado neste caso.…”

“…No Brasil, há poucos relatos da doença em pavões [17,24], no entanto essa condição deve ser incluída como causa de mortalidade para animais dessa espécie e produtores devem estar atentos para sua ocorrência especialmente em aves jovens e criadas em consórcio com outras espécies galináceas mais resistentes.…”

Pathoanatomical and pathogistological changes in organs and tissues of indian peafowl (Pavo cristatus) during histomonosis

“…It is difficult to overestimate the economic losses as a result of this disease, especially for industrial poultry breeding. Histomonosis remains a challenging disease not only for commercial poultry farms, but also for the ones dealing with exotic animals -especially among mini-zoos and homesteads where domestic and exotic birds are kept in small enclosures, irregardless of their age, breed and origin (Popp et al, 2011;McDougald et al, 2012;Oliveira et al, 2017;Costa et al, 2018). This disease has been studied substantially and mentioned as early as 1895 in turkeys, as well as in chickens.…”

“…Birds with their head down or head hidden under their wings, their eyes closed, can be often spotted within the flock. Bird's head may be turning bluish, but this is not always the case and it is not one of the pathognomonic indicators during histomonosis (Hauck & Hafez, 2013;Dolka et al, 2015;Michelazzo et al, 2017).…”