Prevalence of lice infestation in alpaca crias from the southern Peruvian Andes

Lice are very common ectoparasites of humans and other animals. These ectoparasites cause various health problems in the hosts, like alpacas, such as intense itching, skin irritation, hair or wool loss, anaemia, and, in severe cases, reduced milk and meat production due to the stress they cause in the host. Epidemiological studies in alpacas are necessary to determine the magnitude and distribution of lice infestation, which would assist in the implementation of control measures. The aim of this study was to determine the prevalence of lice infestation in newborn and young alpacas (crias) from the provinces of Canchis and Espinar, located in the southern Peruvian Andes. Veterinarians examined a total of 383 alpaca crias less than 6 months of age to diagnose lice infestation. Lice were collected and preserved in 80% ethanol for morphological diagnosis. Also, all animal data such as sex, breed, province, and herd size were recorded for analysis. Lice were detected in 352 out of 383 (91.9%; confidence interval (CI_95%) = 88.7%-94.4%) alpaca crias, and three species of lice were identified: two Anoplura from the Microthoraciidae family corresponding to Microthoracius praelongiceps (Neumann, 1909) (91.9%; 353/383) and M. mazzai Werneck, 1932 (18.5%; 71/383), and one Mallophaga from the Trichodectidae family corresponding to Bovicola breviceps (Rudow, 1866) (11.5%; 44/383). The parasite load was very high, especially in the areas of the neck, arms, legs, armpits, and groin in the infested animals. Only the infestation for M. praelongiceps was associated with provinces but not with other variables. M. mazzai and B. breviceps infestations were not associated with any variable. Future epidemiological studies will be necessary to better understand the interactions between the species of lice and risk factors such as local characteristics and livestock husbandry, as well as the negative effect caused by this parasitism in alpacas.