The chemicals in many dog pest treatments keep your pet flea-free – but according to scientists, they are also poisoning our rivers and even killing bees. James Fair investigates whether there are any other options.
Bruno is an energetic, 18kg lagotto romagnolo, an Italian breed of water dog with floppy ears, thick curly fur and handsome chocolate-and-white markings. He’s in the prime of his life and gives every appearance of being indestructible – but he does, as owner Kath explains, have one Achilles heel. He’s very prone to picking up ticks.
- How to prevent tick bites in dogs
- Deadliest parasites: terrifying microscopic creatures that could haunt your dreams
During one family holiday on the west coast of Scotland, she picked off more than 30 ticks from his body, and his groomer found another 13 the following week. “I try to use an oral tick treatment when I remember to give it to him,” Kath says. “But he spits it out, so I have to break it into small pieces and feed it to him with yoghurt.”
Apart from the sheer unpleasantness of ticks – those little fat bodies that swell up like Augustus Gloop in a river of drinking chocolate, the fact that they actually bury their heads into their victim’s skin, leaving their little legs waving about like a toy doll’s – there’s another reason why you’d want to avoid them. They spread diseases – not just Lyme disease, but others such as babesiosis and even (though it’s still very rare in the UK) tick-borne encephalitis, which can cause some very nasty symptoms.
- How to get rid of fleas on dogs and cats
- How pet owners can be more sustainable, improve pet welfare - and save money - from veterinary surgeon Justine Shotton
For ticks, and other parasites such as fleas and intestinal worms, vets will normally recommend a course of drugs that contain a range of different pesticides, some of which are known as neonicotinoids. Two common ones are fipronil and imidacloprid, but you will also find others such as afoxolaner and milbemycin oxide in some of the many brands that are available. NexGard Spectra is a common one, as is Advocate.
They are mostly very effective at repelling pests, but there is a downside – scientists are increasingly finding evidence that these toxic chemicals are getting into the environment – and rivers and other freshwater courses – in worrying quantities and may be having devastating impacts. Fipronil and imidacloprid, which are the only two that have been properly studied, are 7,000 times more toxic to bees than DDT.
“There are studies from the Netherlands that have shown correlations between imidacloprid and fipronil concentrations and declines in macro-invertebrates, and declines in bird species, at concentrations we see in the UK,” says Rose Perkins, who is a vet and has authored papers on the environmental risks posed by these pesticides. Impacted groups included freshwater snails, flies, mayflies and dragonflies.
Exactly how they are getting into our rivers isn’t completely clear, but some treatments are applied in what are known as ‘spot-ons’, which means they remain on the skin of the pet. If that pet then goes for a swim in the river or gets a treated to a shampoo (and, who knows, a blow-dry?), then the insecticide is washed down the drain and conceivably into a river.
Many vets now recommend year-round treatment (whether or not the pet has any ticks, fleas or intestinal worms at all) as the norm. Perkins is critical of this approach. “We have got into this mindset of recommending general blanket treatment of the whole [pet] population, which would make sense if these products were harmless but that isn’t the case,” she says. “It’s become embedded in the veterinary business.”
Many vets, for example, offer clients health plans that include vaccinations but also year-round parasite control. Perkins argues this is largely unnecessary, and that pet owners should take a more targeted approach, assessing the risk of the dogs and cats according to the season and their lifestyle.
But, argues Ian Wright, also a vet and director of the European Scientific Counsel Companion Animal Parasites (ESCCAP), part of the problem is that the wrong products are recommended or that people are not shown how to use them correctly. That they can be bought online or in supermarkets doesn’t help. He says people regularly come into his practice having applied a ’spot on’ parasite treatment and then promptly washed their pet with flea shampoo. “All that insecticide just goes down the plughole,” he points out.
Ultimately, though, vets have a responsibility to treat pets suffering from any sorts of parasites. “We can debate the pros and cons of prevention, but once you have an infestation, that’s a welfare issue if it’s causing dermatitis in the pet,” he says.
Partly as a result of the growing evidence of the environmental risks of conventional parasite treatments, though for other reasons, too, an increasing range of alternative, eco-friendly products is now available . But neither Wright nor Rose Perkins have any faith that these are viable alternatives. “There is not currently any evidence that what you would call a natural product works,” says Wright.
He makes the point that fleas are an especially tricky pest to deal with – one female can lay 50 eggs a day, so if you don’t eliminate an entire infestation, it’s going to come back. “Using a product that’s 30 per cent effective is pointless, because the other 70 per cent are laying 50 eggs a day. You need something that’s close to 100 per cent effective.”
Most of the so-called natural parasite products use a mix of essential oils such as cedar, lavender and citronella and a product called neem, an oil derived from an Asian tree that has been used traditionally to control pests and diseases. Its active ingredient is azadirachtin, which is said to act as an insect repellent and make it harder for insects to feed and reproduce.
Oliver Bristowe, who founded Pets Purest, which produces a range of natural pet parasite products, says he started the company because “I wouldn’t want to put a load of chemicals into my own body, so why would I want to do the same to my pets?”
There may not be much in the way of science demonstrating the ingredients they use are effective, but Bristowe points out that they have been used for hundreds, if not thousands, of years.
One of the problems, he says, is that no one is funding research into these alternative active ingredients, though there is some science out there which shows they haven’t been simply picked at random. Neem oil, for example, has been found to kill, inhibit growth and result in malformed adults in a species of stink bug, while a paper looking into the use of essential oils to kill and repel ticks found some of them were 100 per cent effective.
Kath, meanwhile, says she had been thinking about changing Bruno’s meds to ones that are applied to the skin because he’s fussy about the oral ones, but changed her mind after she heard they were worse for the environment. “I am particularly cautious of things that are bad for rivers because I like wild swimming,” she says.
So, what should you do if you’re concerned about your pet’s health but don’t want to spend what can be hefty sums on treatments that could also contaminate your local river? There’s no perfect solution, but if you resist the all-year-round prophylactic approach keep an eye on any signs or symptoms, and if you opt for tablets rather than those products that are applied to the skin, then you need to bag and bin all their poo because harmful active ingredients are excreted out in them.
But you should also regularly inspect your pet for fleas and ticks, and have a brush and deticker (a little device with a hook which can be used to twist out the head of the tick) at home. You could also clean your pet’s bedding on a regular basis. And then hope your dog isn’t as attractive to ticks as Bruno.
