Everything pets are itching to tell you about fleas

Press, 11 October 1985, Page 8

Everything pets are itching to tell you about fleas

If you were asked, “What parasite is most commonly found on cats and dogs?” you would probably answer “fleas.” You would be right. Fleas are found on most cats, and on about one in three dogs. As summer approaches they will be the cause of an increasing amount of skin disease in our pets. They will also act as carriers for other disease.

Fleas are wingless insects with long legs adapted for jumping. They are brown in colour, are 1.5 to 3mm long and their bodies are flattened sideways. There are many different species of fleas. Most are adapted to a specific host. So we have cat fleas (Ctenocephalides felis), dog fleas (Ctenocephalides canis), rat fleas (Xenopsylla cheopis), and yes, even human fleas (Pulex irritans).

Fleas are not too fussy about where their next meal comes from, so they may move from one host to another. The most common flea found on dogs is the cat flea.

Fleas are a major cause of skin irritation in animals. The bites are itchy, and dogs are especially likely to injure themselves as they scratch and chew at their skin.

A number of animals become hypersensitive or allergic to flea bites. This is because the fleas inject saliva containing an anticoagulant to stop the blood clotting. It binds with proteins in the skin to form an antigen, and animals sensitised in this way will have an aller-

gic reaction to their own skin components. Flea bite dermatitis is normally seen in the areas of skin that fleas prefer — the lower back ana tailbase — but the whole body can

be involved. Symptoms include loss of hair and small red swellings which may merge to form large patches. These may become infected with bacteria and look pussy. There will be small, black, comma-shaped flea droppings, small (o.smm diameter) white flea eggs, and some fleas in the coat. Fleas are notorious carriers of disease, the rat flea in spreading bubonic plague and typhus. The rabbit flea spreads myxomatosis. Fortunately these

diseases are not in New Zealand at present. Fleas carry a common tapeworm of cats and dogs called Dipylidium caninum. Not a serious health problem, it causes irritation round the bottom and sometimes loss of condition. Fleas are difficult to control. The eggs fall off the host onto the ground or carpet. A maggot-like larva, about smm long, hatches out and crawls into the soil, crevices, or bedding. It spins a silken cocoon and hatches out as the adult

flea. The whole lifecycle takes at least three weeks, but adults may live up to fifteen months and lay 500 eggs.

Most insecticides are effective against fleas, but they must be used regularly on both the host and its environment.

Flea powders, shampoos, and sprays are the most economical treatments, but flea collars seem the most effective, at least on cats. This is probably because they are constantly releasing a small amount of insecticide. If your pet suffers from fleas you will need to clean its bedding weekly. Vacuum the house thoroughly, and use fly spray throughout regularly. Clean kennels and spray with any garden insecticide such as malathion, lindane or diazinon. Favourite sleeping areas in the garden should also be sprayed. If this is done every three weeks it should break the flea’s life-cycle. Pets that are allergic to fleas often need veterinary treatment. This normally involves corticosteroids to soothe the inflamed skin. Some animals can be desensitised by injections of flea antigen. However, there are no simple solutions. Professor Keep, an Australian veterinary dermatologist, once said: “The flea is probably the cause of more dermatological disorder in small animals than all other agents together and, like the poor, it is always with us.”— By HANS ANDERSEN.