Challenges in oral administration of clioquinol dispersed in gel to pair-housed rhesus monkeys (Macaca mulatta)

Abstract

Entamoeba spp. is a common protozoa in rhesus monkeys (Macaca mulatta) and humans (Johnson-Delaney, 2009; Levecke et al., 2007). This parasite can affect the health status of macaques as the infection can cause severe diarrhoea (Johnson-Delaney, 2009). Therefore, in some cases, treatment can be mandatory. Metronidazole is the most common treatment for Entamoeba spp. in veterinary medicine (Jiang et al., 2008; Wright 2012). To handle the animals as little as possible, oral administration of the medication in e.g. drinking water would be optimal. However, the administration of metronidazole in drinking water was not successful in rhesus monkeys due to low fluid intake attributed to undesirable taste (Labberton et al., 2013). We investigated whether another anti amoebic medicine, clioquinol, administered via drinking water could be used to treat rhesus monkeys. A cross-over study was designed in which water, medicated fluid and non medicated fluid was provided to macaques. The normal daily water intake of 16 macaques over a 27-day period was determined. Secondly, it was investigated whether the addition of clioquinol dispersed in gel influenced the daily fluid intake. Furthermore, it was determined if the monkeys drank enough medicated fluid to receive a dose of 20 mg/kg/day clioquinol. The mean water uptake was 78.8 ml/kg. Clioquinol addition resulted in a statistically significant decrease of 15.7 ml/kg in fluid intake. The mean intake of the non-medicated fluid compared with water intake did not significantly differ. The mean intake of clioquinol for five days was 22.4 mg/kg. This study shows that it is possible to administer clioquinol in gel to rhesus monkeys in the desired dose.