Efficacy of prophylactic dosing of diclazuril for the prevention of coccidiosis in captive-reared North Island brown kiwi (Apteryx mantelli) chicks

Sep 30, 2026

Kiwi (Apteryx spp.) chicks raised in conservation captive-rearing programmes commonly develop coccidiosis, a parasitic disease that can cause morbidity and mortality in juvenile birds. Management typically combines husbandry prevention with coccidiocidal drugs, yet evidence indicates limited efficacy of toltrazuril and uncertainty about safe, effective alternatives for young kiwi. This study tested oral diclazuril prophylaxis in chicks naturally exposed in captive facilities, assessing health effects and drug performance using faecal oocyst counts, plasma drug levels, and molecular profiling.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages16

Reading Time40 min

AccessFree to download

Abstract

Introduction

Parasitology Research (2026) 125:3 [https://doi.org/10.1007/s00436-025-08572-3](https://doi.org/10.1007/s00436-025-08572-3) Efficacy of prophylactic dosing of diclazuril for the prevention of coccidiosis in captive‑reared North Island brown kiwi (Apteryx mantelli) chicks Emma Scheltema1 · Preet Singh1 · Laryssa Howe1 · A. Jonathan R. Godfrey2 · Bev Wilkinson3 · Veronika Pipe4 · Kerri Morgan1,5 Received: 26 June 2025 / Accepted: 13 October 2025 © The Author(s) 2026 Abstract Kiwi (Apteryx spp.) chicks in conservation captive-rearing programmes commonly suffer from coccidiosis, a parasitic disease that can cause significant morbidity and mortality in young birds. Current management combines preventative husbandry with treatment using coccidiocidal drugs. However, evidence suggests a lack of efficacy of toltrazuril, the primary drug used to treat coccidia, and limited information is available on safe and effective therapeutic alternatives for juvenile kiwi. This study evaluated the prophylactic efficacy of orally administered diclazuril (Coxiril 0.5%(5 g/kg) microGranulate premix, Huvepharma) for preventing coccidiosis in kiwi chicks naturally exposed to infection in captive-rearing facilities. Kiwi chicks (n = 6) received in-feed diclazuril at 0.5 mg/kg daily for 30 days, starting on the day of transfer to outdoor pens. An untreated control group (n = 6) was monitored in parallel. Health was monitored via clinical observation and blood biochemical analyses, while drug efficacy was measured using a combination of faecal oocyst counts, plasma concentration of diclazuril, and a molecular assay to assess changes in Eimeria spp. composition. In-feed diclazuril was well tolerated, with no adverse effects observed. Treated birds shed significantly fewer oocysts than control birds (p = 0.021) . Changes in coccidia species composition suggested differential susceptibility of some kiwi Eimeria species to diclazuril. Further investigation of the optimal dose and treatment duration is recommended before integration of diclazuril into standard management protocols. Keywords Wildlife health · Drug safety · Anticoccidial · Drug efficacy · Eimeria Introduction Operation Nest Egg (ONE) is a successful captive-rearing programme that aims to hatch and rear chicks of the iconic rare New Zealand native bird, the kiwi (Apteryx spp.), for Section Editor: Livia Perles * Emma Scheltema[e.scheltema@gmail.com](e.scheltema@gmail.com) 1 School of Veterinary Sciences, Massey University, Palmerston North, New Zealand 2 School of Mathematical and Computational Sciences, Massey University, Palmerston North, New Zealand 3 Save the Kiwi, Napier, New Zealand 4 VetServices Hawke’s Bay and Dannevirke, Napier, New Zealand 5 Wildbase, Massey University, Palmerston North, New Zealand release to the wild (Colbourne et al. 2005 ; Robertson et al. 2011) . The programme has been in place since 1994 and has contributed toward growing wild populations of kiwi, with the release of over two thousand juvenile kiwi back to the wild (C. Dean, personal communication, November 14, 2024). However, infection by Eimeria spp., a normally commensal protozoan parasite in healthy free-living host species, is a common cause of morbidity and, sometimes, mortality in captive-rearing facilities in which young immunologically naïve birds are held in naturalistic environments where they encounter much higher concentrations of oocysts than in the wild (Sainsbury and Vaughan-Higgins 2012 ; Morgan et al. 2014). To date, six different Eimeria species have been identified from kiwi: Eimeria kiwii, E. apteryxii, E. mantelli, E. paraurii (Morgan et al. 2017), E. paopaoii (Coker et al. 2023), and E. koka (Scheltema et al. 2025c) . At least one of these species (E. koka) migrates extraintestinally to infect the kidneys and sometimes other organs, such as the liver, spleen, and lungs (Morgan et al. 2013 ; Scheltema et al. 2025c) . Typical symptoms of clinical coccidiosi

FAQs

Why is coccidiosis a concern in captive-reared kiwi chicks?

Coccidiosis is common in kiwi conservation captive-rearing facilities and can cause significant morbidity and mortality in young, immunologically naïve birds.

How was diclazuril given and for how long in the study?

Kiwi chicks received diclazuril in feed at 0.5 mg/kg daily for 30 days, starting on the day of transfer to outdoor pens.

What measures were used to evaluate diclazuril efficacy?

Efficacy was assessed using faecal oocyst counts, plasma diclazuril concentrations, and a molecular assay to evaluate changes in Eimeria spp. composition.

Sep 30, 2026

Upload by Genevieve