Treatment and prevention of tapeworms in dogs and cats.
Tapeworms grow in the small intestine of dogs and cats and pass their eggs into the environment in the pet’s faeces. The life cycle consists of an intermediate host and there is the potential for humans to become infected through accidentally ingesting infective eggs. Although their life cycles are similar, there are three important genera or types to consider because of their prevalence and risk to health:
This species of tapeworm is associated with flea infestations because the flea larvae ingest the tapeworm’s eggs in the environment. When they develop into adult fleas, the tapeworm eggs are ingested by the pet when it swallows the ‘carrier’ flea, which is the intermediate host, whilst grooming. Dipylidium caninum is unlikely to cause serious problems but may produce irritation around the anus and therefore it is recommended to worm your pet if it has fleas.
There are several species of Taenia tapeworm and the intermediate host can vary depending upon the species – ranging from goats, sheep, cattle, pigs, rabbits and rodents. For example, Taenia taeniaeformis eggs may be ingested by a mouse, the larvae develop inside that mouse which is eaten by a cat. Following ingestion of the mouse the larvae will continue their development in the cat to form the adult tapeworm in the small intestine. Like Dipylidium, Taenia species are unlikely to cause serious illness in dogs and cats but are common and may result in irritation around the anal region. The risk of infection is high if you have a cat that likes to hunt or if your dog has access to raw meat or offal.
Distribution of E. granulosus. (Source: ESCCAP Guideline 01, 6th Ed, 2020; www.esccap.org/guidelines/gl1/)
There are two species of Echinococcus that are important because they can cause serious disease in animals and humans due to the formation of cysts in the body, particularly in the liver and lungs, these are Echinococcus granulosus and Echinococcus multilocularis. Infection can occur either directly by the ingestion of eggs that may be in the environment or indirectly by the ingestion of larval stages existing in the intermediate hosts. For Echinococcus granulosus the intermediate host may be cattle, sheep, pigs or horses and therefore it is important to keep dogs away from raw meat, offal and slaughter waste in areas where the parasite is endemic. In the UK, there is a high prevalence in Wales and around the Welsh borders.
Echinococcus multilocularis is found in central and eastern Europe where red foxes are the main reservoir of infection. Therefore the only risk is when travelling with your dog to these regions or importing a dog, particularly rescue cases into the UK. You can read our blog for more information about travelling abroad with your pet and the Pet Travel Scheme. It is strongly advised to get veterinary advice to ensure that your pet is protected whilst abroad.
For effective tapeworm control, it is recommend to use a wormer containing the active ingredient praziquantel.