Found fleas on a new pet? Here's what to do

Becoming a pet parent is full of fun, but there’s bound to be the odd curveball. So, if a new puppy or kitten has also brought fleas into our lives, or a rehomed or adopted pet has brought fleas home with them, don’t worry. Just take a look at what to do now to sort the issue and how to keep the new family member protected in future.

Find out if they’ve been flea treated before

The first step is to find out if they’ve already been flea-treated by the breeder, animal rescue centre or previous owners, what they’ve been treated with and when. The answer to that determines what to do next.

If they’ve already been treated…

If they’ve recently been flea-treated, it’s important not to treat them again until the next treatment interval comes around. For example, some flea treatments can only be applied once a month, others can only be used once every three months.

Sadly for us pet parents, there aren’t any flea treatments that stop fleas from jumping onto pets. If we see fleas on a treated puppy or kitty, it’s probably a new flea that’s just jumped on them from the environment and the flea treatment will soon sort it out. 

The key thing to remember is that the treatment they’ve recently had should be working against these newly arriving fleas. Want to know more about why fleas are still alive after treatment? Take a look at our dedicated info.


If they’ve not been treated…

If a flea treatment hasn’t been given at the previous place, now’s the time to treat them. 

Regular flea treatment helps prevent flea problems building up. Which is good, because female fleas can lay as many as 50 eggs in a day and these eggs will fall off our pets around our homes, leading to a home infestation. That’s the last thing we need when we’re trying to help our new pet settle in!

We’ve got some specific advice on how to get rid of fleas. And it’s good to know that FRONTLINE® spot-on treatments are suitable for puppies aged 8 weeks and over who weigh at least 2 kg and kittens aged 8 weeks and over weighing at least 1 kg.

Was there previously a pet in your home?

It’s a bit yucky to think about, but homes that haven’t had a pet in them for a while can have a flea infestation that’s laid dormant there for months until a new pet arrives and triggers these dormant fleas to hatch. In this case, it’s not the new pet that brought fleas home – instead, the new pet has simply brought these fleas out of hiding.

How does this happen? Well, flea eggs that have fallen off a previous pet (yours or someone else’s, if you’re in a new home) can develop into flea larvae that burrow into carpets, furnishings and nooks and crannies. These larvae then develop into flea pupae, which each contain a developing flea. The presence of a new cat or dog would encourage the new fleas to hatch out and start biting. 

Fortunately, household flea sprays like FRONTLINE HOMEGARD® kill adult fleas, eggs and larvae in our homes. A word of warning – flea pupae are super-strong and impervious to any chemicals, so if they’re already there, new fleas will still hatch out of them. Luckily, the household spray and flea treatment on the pet will kill these new fleas off quickly.

Worried about a dormant flea infestation? Use a household flea spray, just in case – and remember to treat pets with a suitable product too.


What to do to help pets stay safe from fleas in future

Regular treatment is always important for our pets. It’ll help them stay happy and healthy in their new homes with us, and that’s what we want. Take a look at our flea prevention advice to see how to stay on top of these parasites.

Now we know what to do, we can deal with what’s happening and carry on basking in all the love and laughter a new pet brings!

Get answers from the experts

Got a question about fleas, ticks or worms? We can help! Take a look at our FAQs or send us a message.

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