Current anthelmintic treatment is not always effective at controlling strongylid infections in German alpaca herds

Abstract

Background Endoparasites are considered a major health problem of South American camelids as shown in a recent survey among German and Austrian camelid owners. Although prophylactic and therapeutic measures such as application of anthelmintics are commonly used, treatment efficacy is usually not assessed. Owners have expressed significant concerns regarding the effect of antiparasitic therapy, so this study aimed to evaluate the outcome of anthelmintic treatment in German alpaca herds with different drugs. Results Overall, 617 samples from 538 clinically healthy alpacas > 1 year-old from 27 farms ( n = 11–157 animals/herd) were examined. The most common parasites detected by flotation were Eimeria spp. (75.1%) followed by strongylids (55.0%), Nematodirus spp. (19.3%), cestodes (3.1%) and Trichuris (2.7%). After initial coproscopical examination by flotation and strongylid egg quantification by the McMaster technique, positive animals excreting at least 150 eggs per gram of faeces were included in a faecal egg count reduction test (FECRT) using fenbendazole ( n = 71 samples), moxidectin ( n = 71) or monepantel ( n = 66). Pre-treatment larval cultures ( n = 23 positive pooled farm samples) revealed Haemonchus (87% of the farms), Cooperia (43.5%), Trichostrongylus (21.7%), Ostertagia (13.0%), Nematodirus and Oesophagostomum (4.3% each). Fenbendazole treatment reduced egg excretion by 45%, moxidectin by 91% and monepantel by 96%. On the farm level, 13/18 farms that used fenbendazole, 6/6 farms that used moxidectin and 2/5 farms that used monepantel had individual FECR values < 90% (fenbendazole) or < 95% (moxidectin, monepantel). Haemonchus and Cooperia were overrepresented on the farms with reduced treatment efficacy. Conclusions Gastrointestinal strongylids are common in German alpacas and fenbendazole in particular was not sufficiently effective to reduce strongylid egg excretion. Although the FECRT could not unambiguously determine anthelmintic resistance in the present study, the finding that small ruminant strongylids, especially Haemonchus , are common in alpacas indicates that determination of effective anthelmintic doses, monitoring of efficacy and adapted (selective) treatment regimens must be implemented as part of sustainable deworming practices in this species in accordance with recommendations for ruminants.

Eimeria control in baby alpacas using toltrazuril as a prophylactic measure in humid Puna

“…With reference to the effect of the drug among eimerias species, 94 % (47/50) of alpaca offspring have the presence of some eimeria species, a higher percentage than that reported by Salazar Robayo 24 , Camareno et al 25 and Kultscher et al 26 It is important to distinguish the species of parasites, because they can be simultaneously infecting a host, and vary in pathogenicity in their biology 29 , so we take as a reference for pathogenicity E. macusaniensis. This specie causes moderate to severe lesions in the gut alpaca and can kill them with signs diarrhea 23 .…”

Anthelmintic resistance in small ruminants in the Nordic-Baltic region

“…In addition, domestic interactions through contacts with "exotic" livestock, such as alpacas, may also be a contributing factor. It has been documented in some countries that imported camelids are sometimes infected with Haemonchus that are refractory to anthelmintic treatments [61,62].…”

Survey of anthelmintic use in South American camelids in the UK

“…14 Anthelmintic resistance has already been reported in camelid helminths in USA, Belgium, Australia, and Germany. [5][6][7][8] While many anthelmintics have wide safety margins, overdosing may be causing unnecessary toxicity in animals without improving anthelmintic efficacy and will be a cause of economic loss on commercial farms. 15 Despite the small scale of this study, it raises concerns about the use of anthelmintics for the treatment of camelids in the UK and highlights the need for quality efficacy studies to provide veterinarians with appropriate evidence-based knowledge that they can then pass onto their clients.…”

“…Despite this, there are no products licensed for anthelmintic treatment in camelids and no published thresholds over which treatment is indicated in these species. This uncertainty can lead to animals being treated according to anecdotal evidence, or to regular blanket deworming by the owner, potentially resulting in either over‐dosing or emergence of anthelmintic resistance, which has been reported in camelids in the USA, Belgium, Germany and Australia 5–8 …”

“…This uncertainty can lead to animals being treated according to anecdotal evidence, or to regular blanket deworming by the owner, potentially resulting in either over-dosing or emergence of anthelmintic resistance, which has been reported in camelids in the USA, Belgium, Germany and Australia. [5][6][7][8] There is very limited information available on the use of anthelmintics in UK camelids. The aim of this study was to assess current gastrointestinal helminth control practices among alpaca and llama farmers in the UK, with particular emphasis on anthelmintic usage.…”