Efficacy of doramectin against naturally acquired nematode infection in Iberian swine

Studies were carried out to determine the therapeutic efficacy of doramecti n, administered intramuscularly at a dose of 300 mu g/kg live weight, again st naturally acquired helminths of extensively farmed Iberian pigs. The fir st study (slaughter study) evaluated, through necropsy of the study animals , the product's efficacy against gastrointestinal and pulmonary nematodes ( Ascaris suum, Oesophagostomum dentatum and Metastrongylus sp.) whilst the s econd, faecal egg count reduction study, (FECR study) evaluated the drug's efficacy only against gastrointestinal helminths (A. suum, Trichuris suis a nd Oesophagostomum sp.). The first study used 20 animals divided into two equal groups of 10 on the basis of body weight and faecal egg count. One group constituted saline tre ated controls and the other was doramectin treated. On Day 14 post treatmen t half of the animals in each group were necropsied and the number of paras ites present counted. On Day 15 the remaining half of each group underwent the same procedure. The second study was carried out with 40 animals divide d equally into two groups of 20. This study determined the effect of dorame ctin treatment on faecal egg counts as an indicator of parasite burden. The first study demonstrated an efficacy of 100% against adult Metastrongyl us sp. and A. suum, whilst the efficacy against O. dentatum was 96.3%. The second study indicated that at Day 21 post treatment there was a 100% reduc tion in egg counts in faeces in comparison to untreated controls. (C) 2000 Elsevier Science B.V. All rights reserved.