Quick refreshers on key topics , by Frank Ruedisueli

ABSTRACT Helminths are divided into three types : nematodes ( roundworms ), cestodes ( tapeworms ) and trematodes ( flukes ).

All three types occur in companion animals , although flukes are not common in cats and dogs in the UK and mainly affect ruminants .

There are thousands of species of cestodes ( tapeworms ). This article will focus on the species in Table 1 [ 1 ] . In most cases a cestode ' s pathogenicity is limited in the end host ( EH ) but infection of an unintended intermediate host ( IH ) can cause disease . Cestodes have a flattened body plan ( Figure 1 ), in comparison to the cylindrical shape of nematodes ( see article on nematodes , from page 50 ).

This article will focus on the morphology , life cycle and treatment of cestodes , with special attention given to Dipylidium caninum , Taenia species and Echinococcus granulosus .

Keywords helminths , cestodes , tapeworms , life cycle , treatment

Figure 1 . Cestode ( tapeworm ). [ Image : iStock ]

54 Veterinary Nursing Journal