Kittens are first exposed to intestinal worms soon after birth, as they commonly become infested with roundworm transmitted in their mothers milk. Adult cats are exposed to worms through soil in the outdoor environment, as well as from eating small animals like mice who can act as intermediate hosts for some species of gastrointestinal worms. Heavy infestations with worms can cause diarrhoea, weight loss, poor growth and anaemia. Kittens are particularly susceptible to problems caused by infestion with intestinal worms, so they should be wormed more frequently than adult cats. Kittens should be wormed every fortnight from 2 to 12 weeks of age, then every month until 6 months of age. Adult cats and kittens over 6 months old should be wormed at least every 3 months. Safe for kittens weighing over 0.5kg from 6 weeks of age as well as pregnant and lactating queens.