Toxascaris Leonina: Dog and cat roundworm

General Description: Typical roundworm; males up to 7cm long, females up to 10cm. The eggs are oval with thick smooth coat.

Life Cycle: This roundworm infects dogs, cats, foxes and wild animals such as wolves. Toxascaris leonina has a simple, direct life cycle. The infective second-stage larva develops inside the egg 3 to 6 days after leaving the host. Larvae hatch after being ingested. The larvae burrow into the wall of the intestine, moult and return to the intestinal lumen to mature. The prepatent period is 6 weeks. Mice serve as transport hosts.

Location: Small intestine.

Geographical Distribution: Worldwide

Significance: Damage occurs only in young cats, producing poor general condition and possibly death if uncommonly large infections are present.

Effect on Host: Infected kittens have potbellied appearance and intermittent diarrhoea and show poor general condition. Intestinal obstruction can be caused if large numbers of worms are present.

Diagnostic Information: Characteristic eggs can be identified in the faeces of infected cats.

Control: Infected cats can be treated with appropriate drugs. Faeces removal is important in controlling feline ascarids.

Tangled mass of ascarids		T.leonina – scanning electron microscope photo of mouth parts
Eggs – T. leonina – cat faeces		T. leonina – egg enlarged