Eradication of sarcoptic mange from a Belgian pig breeding farm with a combination of injectable and in‐feed ivermectin

Abstract

Sarcoptes scabiei var suis was eradicated from a Belgian pig farm by using a combination of injections of ivermectin and ivermectin in the feed. The detection of mites in ear scrapings, and calculations of an average dermatitis score and a scratching index were used to evaluate the mange status of the pigs before and after the treatment. Before the treatment 28 per cent of ear scrapings of finishers were positive for the presence of mites, their average dermatitis score (ADS) was 0.92 and their scratching index was 2.0. There was a significant decrease in all three measurements during the year after the treatment, and one year after treatment, no mites were found in the ear scrapings; the ADS of the finishers was 0.31 and their scratching index was 0.16. Adult animals were negative for the presence of mites at all times, the ADS was below the cut-off level before and after treatment, and the scratching index decreased after treatment There was an economic improvement among the breeding sows and the fattening pigs. The feed consumption of the sows decreased by 5 per cent; rebreeding decreased by 4.55 per cent; average litter size increased by 0.33 live piglets born per litter and the farrowing index increased by 0.075 litters per sow per year. As a result, the production index increased by 1.34 more piglets weaned per sow per year. There was an immediate improvement in feed conversion during the five months after the treatment. The costs of the treatment were recovered within 3.7 months.

Prevalence, risk factors and economic importance of infestations with Sarcoptes scabiei and Haematopinus suis in sows of pig breeding farms in Hesse, Germany

“…The aim of both the traditional ‘targeted’ (selective) and ‘non‐targeted’ (whole‐herd) treatment strategies is to prevent the piglets from mite infestation, but the infestation is usually kept at a subclinical level in the farm. However, only the whole‐herd treatment strategy with at least two treatments at an interval of 2 weeks enables, in principle, an eradication of sarcoptic mange from a farm (Jacobson et al ., 1999; Smets et al ., 1999).…”

Elimination of Mange Mites Sarcoptes scabiei var. suisfrom Two Naturally Infested Danish Sow Herds Using a Single Injection Regime with Doramectin

“…The specificity of the test, however, makes it insufficient for use as the only tool. According to findings in other studies [22,17] a rubbing index at or above 0.4 may be found even in mange-free herds. A seasonal variation has been suggested [17] with a higher index recorded during the summer months.…”

“…In conclusion, a 2-injection strategy which has been used successfully under field conditions for many years [10,12,18,19,14,7,21,15,22] seems to be the most effective method, when using ivermectin. According to this study, the results from an experimental trial [6] and results reported in a field trial [17], the single injection strategy is effective when using doramectin.…”

“…In farrow-to-finish, continuous flow production sites, a barrier zone must be established between treated and non-treated pigs ( Henriksen et al 1986) in order to prevent reinfection of treated pigs from non-treated fatteners. Alternatively, pigs close to slaughter could be treated with an acaricide that has a shorter withdrawal period than the injectable avermectins [22]. …”

Vaccination against parasites – status quo and the way forward

“…An exception is the control of mange; S. scabiei has no long-lived environmental stage and relies on direct contact for transmission, so systematic application of acaricides can effectively reduce infection and stamping out the parasite on a farm is possible when quarantine measures and proper diagnostic screening are in place (e.g. [38]). However, sustainability is jeopardized by the development of acaricide resistance as reported from human scabies [22].…”