Equine tapeworm infections: Disease, diagnosis and control

Abstract

Summary Equine tapeworm infection has gained increasing attention over the past few decades and a number of research studies have already been published. These focus primarily on the most common of the 3 tapeworm species, Anoplocephala perfoliata, although some new information has also been generated for the other two species, Anoplocephala magna and Anoplocephaloides mamillana. The preponderance of research studies have focused on development and validation of diagnostic techniques for tapeworm detection and the role of these parasites in equine gastrointestinal disease. Several diagnostic techniques have been found useful for diagnosis of A. perfoliata but each has its strengths and weaknesses. Egg counting techniques have been modified to achieve acceptable to good diagnostic performance but the trade‐off is often a more time‐consuming method. Validation studies indicate that these methods can reliably detect tapeworm burdens above 10 worms. Several enzyme‐linked immunosorbent assays (ELISAs) have been developed and made commercially available. These can generate useful information about tapeworm exposure on the herd level but are less reliable for individual diagnosis. Unfortunately, none of the available diagnostic techniques are useful for evaluating anthelmintic treatment efficacy. Coproantigen testing may find use as a future diagnostic modality but further characterisation is required. The large body of scientific evidence supports an association between A. perfoliata infection and certain types of equine colic, although some discrepancy exists between studies. Tapeworm surveillance and control should be considered as part of the overall parasite control strategy. When properly used, the currently available diagnostic tools can guide the veterinarian to make strategic decisions regarding tapeworm control.

Parasite Occurrence and Parasite Management in Swedish Horses Presenting with Gastrointestinal Disease—A Case–Control Study

“…The prevalence of A. perfoliata reported here is in accordance with a previous Swedish case-control study that showed positive samples in 13% (18/134) of horses [11]. Previous studies have shown conflicting results regarding the association of tapeworm infection and general colic [7]. However, A. perfoliata has consistently shown to be associated with ileocecal lesions [8,10,[45][46][47][48][49].…”

Use of a saliva‐based diagnostic test to identify tapeworm infection in horses in the UK

“…In comparison, coprological diagnosis of Anoplocephala infection is highly variable, in part due to the sporadic release of tapeworm eggs, poor distribution of eggs in faeces, the FEC technique used and the burden present . Modified FEC methods, such as the centrifugation/flotation technique, are most sensitive, reporting up to 61% sensitivity; however, they are more time‐consuming and labour intensive than standard methods . Sensitivity of the centrifugation/flotation technique can be increased to approximately 90% when diagnosing infections with >20 tapeworms present .…”

“…Studies in the UK and Ireland have shown A. perfoliata to be present in 51–69% of horses examined . These parasites have been associated with colic, weight loss and colitis . Previously, frequent all‐group administration of anthelmintics was used to control equine helminths; however, interval treatment‐based practices strongly selected for anthelmintic resistance, especially in cyathostomins and P. equorum .…”

Equine de-worming: a consensus on current best practice

“…Less than 50% of adult horses in the UK are infected with adult tapeworms (Proudman and Trees, 1996;Lightbody et al, 2016), and many of these have subclinical infections. The risk of tapeworm-associated disease in adult horses is not well quantified (Nielsen, 2015) and colic associated with tapeworm infection appears to be relatively uncommon in most populations of adult horses (Bowen, Rendle unpublished data). Treatment should only be administered to adult horses in response to positive serum or salivary antibody testing.…”