Efficacy of Ivermectin Delivered via a Controlled‐Release Capsule against Small Lungworms (Protostrongylidae) in Sheep

Abstract

To evaluate the efficacy of an ivermectin controlled-release capsule (CRC), which delivers 1.6 mg ivermectin per day intraruminally for 100 days to sheep weighing 40-80 kg (IVOMEC Maximizer CR Capsule for adult sheep, Merial), against small lungworms two studies with 48 naturally infected adult female Merino Landrace sheep were conducted. The sheep were allocated by restricted randomization based on bodyweight to untreated controls or received an ivermectin CRC. Eight sheep per group were necropsied 35, 70 or 105 days post-treatment. Lungworms were recovered by dissection or peptic digestion of the lungs. Baermann/Wetzel technique was used for faecal lungworm larval counts at weekly intervals. The efficacy of treatment was 100% against Dictyocaulus filaria and Protostrongylus rufescens (P < 0.05) at each necropsy day. The efficacy against Protostrongylus brevispiculum, Cystocaulus ocreatus and Neostrongylus linearis increased from 35 to 105 days after administration of the CRC and was found to be 100% (P < 0.01), 96.6% (P < 0.01) or 99% (P < 0.01), respectively, at 105 days post-treatment. The reductions of Muellerius capillaris counts varied and were 96.2% (P < 0.05) at 70 days post-treatment and 44.6% (P > 0.1) at 105 days post-treatment. Faecal lungworm larvae disappeared nearly completely from at least 3 weeks after the ivermectin CRC administration for all protostrongylid species including M. capillaris so that pasture infectivity will be subsequently significantly reduced.

Efficacy of eprinomectin pour-on treatment in sheep naturally infected withDictyocaulus filariaandCystocaulus ocreatus

“…The benzimidazole (Cremers, 1983; Bliss & Greiner, 1985; Hele, 1986; Jones & Worley, 1997), pro-benzimidazole (Cabaret, 1991; Kulo et al , 1994) and avermectin (Gıcık et al , 2002; Hidalgo-Argüello et al , 2002; Rehbein & Visser, 2002; Papadopoulos et al , 2004) class of drugs is used for the treatment of lungworm infections in small ruminants. Currently available anthelmintics are poorly effective against protostrongylid lungworms, in particular against the lung parenchyma-dwelling species.…”

Efficacy of Broadline® against Capillaria aerophila lungworm infection in cats

“…Lungs were examined by lengthwise opening of the accessible airways, extraction of lungworms with a needle and rinsing of the dissected lungs. In addition, the whole lung tissue was digested artificially as described previously (Rehbein and Visser 2002), and the digested material as well as the lung rinse were examined under a dissection microscope for capillarid nematodes. Capillarid nematodes recovered were identified to species based on their morphology (Skrjabin et al 1970) and counted.…”

Endoparasites of cats from the Tirana area and the first report on Aelurostrongylus abstrusus (Railliet, 1898) in Albania

“…Gastrointestinal helminths were recovered using standard techniques. Nematodes of the lungs were recovered following artifi cial digestion of the whole lung tissue according to the method described by Rehbein and Visser [52]. In addition, tissues of two lungs with lesions characteristic of lungworm infection were processed for routine histopathology.…”