Some advice for pet owners from DROVE VETERINARY HOSPITAL.

  • What are Worms?

There are a many species of parasitic worm in the UK that commonly infest our pets, including various species of roundworm, hookworm, lungworm and tapeworm.

Toxocara canis and toxascaris leonina are the most important roundworms as they are the most common worms to infest our pets and they are a risk to public health, especially children.

The adults live in the guts of dogs and cats, and shed eggs in the faeces. The worms can be several centimetres long and look a bit like spaghetti.

The eggs are really sticky and are extremely hardy, being able to survive in the environment for years.

Once ingested, the eggs hatch into larvae which develop into adults in the gut. In pregnant dogs, the larvae can cross the placenta into unborn pups, and can be transmitted via the mother's milk.

In cats, there is no placental transmission, but larvae can be transmitted via milk. Any larvae ingested by small prey, such as mice, lay dormant within the prey until hunted, when they reactivate and develop into adults. This mode of transmission most commonly occurs in cats that are keen hunters.

Adult tapeworms live in the gut of dogs and cats. They shed segments of their tail which contain large numbers of eggs, into the faeces. In some species, these segments look like short, fat, white worms, and wriggle around a lot when alive. When dead they resemble grains of rice.

All tapeworms need to complete part of their lifecycle in a suitable intermediate host, which becomes infested by eating the tapeworm segments. The dog or cat then eats the intermediate host, allowing the larval stage of the tapeworm to develop into an adult, and start laying eggs in the faeces.

Dog tapeworms commonly use sheep or larger prey species as their intermediate hosts, while cat tapeworms often develop within small prey species.

The most common tapeworm, dipylidium caninum, is transmitted by fleas, and it is the segments of this tapeworm that owners most commonly notice in the faeces.

The eggs are ingested by flea larvae, which then develop into tapeworm cysts within the adult flea. When the animal grooms, or when licking its bottom, it inadvertently ingests the adult fleas, allowing the tapeworm to develop into an adult.

Although truly revolting to look at, and often the reason that pet owners wish to worm their pets, these segments are harmless to humans. Indeed, it is those worm eggs that are not visible to the naked eye that are the real threat.

  • Why do I need to worm my pet?

Worms can cause weight loss and tummy upsets in our pets. They can cause a significant pot-bellied appearance and abdominal discomfort in puppies and kittens, and in severe infestations can cause gastrointestinal obstruction, which may require emergency surgery.

Some dog and cat worms can cause serious disease in humans. The roundworms, toxocara canis (dog) and toxascaris leonina (cat) can both cause serious disease in humans.

They can cause a syndrome called visceral larval migrans whereby the larvae burrow into the human, infest muscles and can cause blindness if they manage to migrate into the eye. Some of you may well remember publicity surrounding this as a cause of blindness in children in the 1980s.

Hookworms can cause cutaneous larval migrans - a term used to describe the process by which hookworm larvae may burrow through the skin of the feet or legs of humans, leaving an intensely itchy trail. Cases of chronic diarrhoea and anaemia have been reported to occur in small children.

  • So how do we treat worms?

All adult cats and dogs should be wormed every three months, throughout their lives.

Unweaned pups and kittens should be wormed fortnightly from three weeks old. Once weaned, this can be reduced to monthly until six months old, then every three months. Pregnant bitches should be wormed daily in the later stages of pregnancy, until a few days after whelping. Mothers should be wormed at the same time as the pups/kittens thereafter.

There are a number of suitable, reliable wormers available. The ideal one for you will depend on you and your pet's personal circumstances.

Wormers are available in granules, pastes, tablets, spot-on preparations and injections.

Some spot-on preparations also treat fleas and mites, providing good all- round cover. However, they do not usually treat for tapeworm so a wormer that can mop up any tapeworms should be administered at least twice yearly.

Please ensure that you use an appropriate product.

Consult your local vet for further help and advice.