Intranuclear coccidiosis caused by Cyclospora spp. in calves

Abstract

Abstract. Intranuclear coccidiosis in 3 calves is described. Two calves with no genetic relationship were kept in the same pen, and the third calf was on another farm. The animals suffered from watery diarrhea or severe emaciation. Histologic examination showed epithelial desquamation (cases 1 and 2) or atrophy (case 3) of the jejunal villi. Coccidial meronts or merozoites were present in the nuclei of the majority of villus epithelial cells. There were rare intranuclear macrogametocytes, macrogametes, microgametocytes, microgametes, and oocysts in cases 1 and 2, but these were more easily observed in case 3. Parasite 18S ribosomal RNA sequences from case 1 showed 99.5% sequence identity with Cyclospora sp. Guangzhou 1, which has been found in fecal samples of cattle from China. In addition to the molecular results in one of the cases, the fact that the microgametocytes and oocysts were noticeably smaller in size than those of Eimeria alabamensis in all cases indicates the close association between Cyclospora and the 3 cases described herein.

Coccidiosis in Wild Eastern Newts (Notophthalmus viridescens): An Unexpected Finding in Consecutive Mortality Events in Tennessee, USA

“…Coccidia PCR was performed on liver from 2017 and pooled liver and intestine from 2019, and FFPE on intestinal sections from both years. We performed an initial PCR amplifying the Eimeria 18S ribosomal DNA with primers Ei18sr1 and Ei18Sf1 (Yamada et al 2014) followed by another PCR targeting the 18S ribosomal subunit of tissue cyst–forming protozoa with primers tg18s48F and Tg18s359R (da Silva et al 2009). Reactions were 25 µL with 1 µL of each primer, 12.5 µL of dreamTaq Green PCR Master Mix (Thermo Fisher Scientific Inc.), 8.5 µL of nuclease-free water, and 2 µL of DNA.…”

Pathology in Practice

“…Intranuclear coccidiosis has been described in many other species of reptiles, as well as farm animals, small mammals, and birds, and this condition is most often caused by coccidia of the genus Eimeria or Cyclospora. [9][10][11] Intranuclear coccidiosis is believed to most often be asymptomatic or cause minimal clinical signs in most species, but there have been reports 9,10 of substantial morbidity in calves. Clinical signs typically include anorexia, growth retardation, and watery diarrhea, and most animals either die or are euthanized after failure to respond to treatment.…”

“…Clinical signs typically include anorexia, growth retardation, and watery diarrhea, and most animals either die or are euthanized after failure to respond to treatment. 9,10 Case reports [9][10][11] from both calves and geese demonstrate fecal-oral transmission, and oocysts appear to also be difficult to detect on routine fecal flotation. 10 Gross abnormalities in calves range from none to enlarged mesenteric lymph nodes and thickening of the small intestinal mucosa.…”

“…9,10 Case reports [9][10][11] from both calves and geese demonstrate fecal-oral transmission, and oocysts appear to also be difficult to detect on routine fecal flotation. 10 Gross abnormalities in calves range from none to enlarged mesenteric lymph nodes and thickening of the small intestinal mucosa. 9,10 Interestingly, Yamada et al 10 described absence or atrophy of the thymus in 2 cases.…”

“…9,10 Interestingly, Yamada et al 10 described absence or atrophy of the thymus in 2 cases. In both calves and geese, intranuclear coccidia are present throughout the gastrointestinal tract, [9][10][11] but in calves, the highest concentration is in the jejunal villi with atrophy of the villi a common histologic finding in this species. 9,10 Intranuclear coccidia in calves can lead to major economic loss because the organisms are difficult to detect on routine fecal examination and affected individuals typically show nonspecific clinical signs.…”