Ticks, fleas and heartworm: building a year-round defence in Hong Kong

Hong Kong's subtropical climate means there is no winter break for parasites. Ticks, fleas and heartworm are twelve-month threats, and the cheapest, safest approach is consistent prevention rather than treating the disease that results.

Ticks here carry babesiosis and ehrlichiosis — blood parasites that can cause severe anaemia and organ damage. Dogs that hike in country parks, walk through long grass, or share parks with stray dogs are at highest risk, but ticks travel on other animals and on people, so even city dogs are exposed.

Fleas cause more than itching. They trigger flea allergy dermatitis (one flea can set off weeks of skin inflammation in a sensitive dog), transmit tapeworm, and in heavy infestations can anaemia kittens. Fleas also infest the home, and clearing an established infestation takes months.

Heartworm is the one I worry about most. Transmitted by mosquitoes, the worms mature in the heart and pulmonary arteries over months. By the time a dog coughs, tires on walks or loses weight, the disease is advanced — and adult heartworm treatment is prolonged, expensive and itself carries risk. Monthly preventive is close to 100% effective.

A practical plan: a monthly broad-spectrum product covering heartworm, fleas and intestinal worms, with explicit tick cover added for dogs that go to country parks. Some owners prefer three-monthly oral products for ticks and fleas combined with monthly heartworm — both are valid if used on schedule.

Indoor cats are not safe by default. Mosquitoes carry heartworm to indoor cats, and fleas hitchhike in on shoes and other pets. Heartworm in cats has no safe adult treatment, which makes prevention the only real defence.

Test annually. A heartworm antigen test at the yearly check confirms your prevention is working, and a faecal screen checks the worm programme. Prevention only works if it is genuinely every month, all year — gaps are where infections happen.