Eimeria macusaniensis infection in 15 llamas and 34 alpacas

15 llamas and 34 alpacas between 3 weeks and 18 years old with fecal oocysts or intestinal coccidial stages morphologically consistent with Eimeria macusaniensis were examined. Nineteen of the camelids were admitted dead, and 30 were admitted alive. Camelids admitted alive accounted for 5.5% of all camelid admissions during this period.

Many severely affected camelids had signs of lethargy, weight loss, decreased appetite, and diarrhea. Camelids with clinical infection also commonly had evidence of circulatory shock, fat mobilization, and protein loss. Nonsurviving camelids also had evidence of shock, edema, bile stasis, renal insufficiency, hepatic lipidosis, muscle damage, relative hemoconcentration, and sepsis. Postmortem examination frequently revealed complete, segmental replacement of the mucosa of the distal portion of the jejunum with coccidial meronts and gamonts. For 17 of 42 camelids, results of initial fecal examinations for E macusaniensis were negative.

Most camelids admitted alive were treated with amprolium hydrochloride, plasma, and various supportive treatments. Fifteen of the 30 treated camelids died or were euthanized.

Findings suggest that E macusaniensis may be an important gastrointestinal tract pathogen in camelids of all ages. Clinical signs were frequently nonspecific and were often evident before results of fecal examinations for the parasite were positive. As with other coccidia, severity of disease was probably related to ingested dose, host immunity, and other factors. The clinical and herd relevance of positive fecal examination results must be determined.