Whipworms and hookworms can affect both dogs and cats, and both types of worm live off the animal’s blood. Though they are not very big (around 70 mm and 100 mm respectively) their feeding habits can make them very damaging, particularly in young animals, where they can cause diarrhoea, anaemia, weight loss and lethargy.
Hookworms, incidentally, are a growing threat, largely because so many foxes are infected. Studies have shown that about 7 out of 10 UK foxes carry the hookworm Uncinaria stenocephala, and with an ever-growing urban fox population, even city-dwelling dogs are at risk.