Animals - War against fleas and ticks

By David HaughWhen I came to work in Northland, back in the 1980s, I remember turning up on farms in the summer and looking over at the working dog(s). So often they had next to no hair on the rear half of their backs. This is where they had spent much of their spare time biting at the itch caused by fleas biting them … and the fleas were winning.

Each adult female flea, which can live and feed for many months on your pet, can produce 400 to 500 eggs which fall off the cat or dog host. In ideal conditions (guess where) the egg/larva/pupa/adult life cycle can be completed in three weeks. Then you have young adult fleas in the environment looking for a life-long relationship with the first host to walk past within jumping distance.

Back in the ’80s we had organophosphate powders, rinses and sprays to treat fleas. They worked for a few days, but were soon gone, especially if your dog jumped in a trough or a stream. There were OP collars which worked pretty well up the head end for a few weeks. Then came the OP pour-on, which was too borderline poisonous to gain popularity.

‘Program’ and ‘Capstar’, which went in your pet’s food, came and went next. The former made their fleas infertile, the latter killed adult fleas for one day. Permethrin rinses and collars became available … safer than OPs but, again, easily lost from the coat.

The 1990s brought a huge breakthrough – fipronil (‘Frontline’) and imidoclopramid (‘Advantage’). Fipronil treats fleas and ticks. It comes as a spray and a pour on. Imidoclopramid treats fleas and comes as a pour on. These products are very safe and hang in there for weeks, even with some host swimming. In recent years the patent restrictions have come off Frontline and Advantage, so cheaper generics are available.

Manufacturers have added extras, such as insect growth regulators to make the fleas infertile in the period before they die, and also wormer preparations. This decade we have seen the arrival of the tablet spinosad (‘Comfortis’) which kills fleas on cats and dogs for a month. Then came the tablets afoxolaner (‘Nexguard’) for dogs, that kill fleas and ticks for a month, and fluralaner (‘Bravecto’) for dogs that kill fleas and ticks for 12 weeks. The modern permethrin collar, ‘Seresto’, has a much advanced formulation compared with its 20th century forerunners and is claimed to kill fleas on cats and dogs for eight months.Flea bite saliva is not the only allergen causing trouble in our pets, but it is number one, and these days you have a large choice picking effective weapons to fight it. If you have one dog or cat without many neighbourhood cats visiting then I recommend, at theses latitudes, treating fleas regularly for the nine warmest months of the year. In multiple-pet households, treat all year round.

Ticks have a different life cycle from fleas. The larvae, nymphs and adults of the cattle tick we have can jump on our cats and dogs to feed for a while before they decide to hop off, but we need cattle to maintain flourishing tick populations. So if you live in town you may never see them. They are nowhere near as annoying as fleas, but aren’t a good look. If you see them, the impulse is to brush them off, but this can leave their mouthparts still embedded in your pet’s skin. Ideally, use a tickicide. While our ticks can carry and transmit a microscopic, protozoal parasite that can affect the health of (predominantly very young) cattle, there is no worry for other species.

David Haugh

Animals - Wellsford Vet Clinic

Animals – War against fleas and ticks

David Haugh

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