We live near a large forest which is great for walks, but no so great for muddy dogs. This means that we not only have to stay on top of tick and flea treatments, but also baths due to the mud our dog gets caked in every week.
Our dog has his topical flea medicine treatment applied once a month, and often the date it falls on happens to coincide with him getting really dirty and needing to be washed the next day.
Just like you, I wondered how soon after flea treatment it’s okay to bathe and wash your dog. After all, water would assume could wash the topical flea treatment away.
To get to the bottom of it I checked out various brand names such as Frontline and Advocate. I will share the information below so you know whether you can bathe your dog after flea treatment.
How long after flea treatment can I bathe my dog? You should wait at least 48 hours to bathe your dog after flea treatment. Whilst most topical flea medicines are waterproof, it’s best to wait for 2 days as a bath or shower could wash the flea treatment off, rendering it ineffective.
Will a bath wash off flea medicine?
If you’ve recently applied flea treatment to your dog, taken them for walk, they’ve got really muddy, and then they need a bath within 48 hours… will the bath wash off the flea medicine?
The majority of flea medicines that you spot-on your dog will be waterproof, so after 48 hours a bath or rain should be fine. Under that time limit, then yes, it could wash off the flea medicine.
If you do decide to bathe your dog during the first 7 days after they have had a flea treatment, use a non-stripping shampoo that won’t remove their skin’s natural oils. This will help to ensure that your dog continues to get the best protection against ticks and fleas.
The bottom line is, you can bathe your dog 48 hours after flea treatment, anything under that and you could be risking the treatment being washed off.

What the flea treatment manufacturers say
I also decided to check in with what the big-name brands say about how long after flea medication you can bathe a dog. Here are what their websites state:
How long after using Frontline can I bathe my dog?
Frontline say that your dog should not get wet up to 24 hours after applying their Frontline Plus flea treatment. Whilst that’s not as long as I personally advise, it’s key to understand that by wet, they might simply mean a little rain.
There’s a big difference between a dog getting wet from rainfall and being scrubbed in a bath or shower. Here’s what Frontline also say:
“Re-treatment may be necessary on some occasions, for example if your dog is a frequent swimmer; in these cases, do not treat more frequently than once weekly.”
Based on that, I’d still recommend you wait 48 hours after applying Frontline flea treatment before you bathe your dog.
When can I bathe my dog after advocate flea treatment?
Advocate are a little clearer with their instructions explaining that showers and baths can wash off flea medicine if done within 48 hours of being applied.
WARNING: In the last 12 months there has been research to suggest that dog flea collars can be very dangerous to dogs.
What about bathing a dog before flea treatment?
The guidance is the same, leave a 48-hour window. The reason being, topical spot-on flea treatments are dispersed through the dog’s coat by their natural oils.
A bath and shampooing can strip a dog’s coat of natural oils; the flea medicine will pool up by the dog’s neck and not be as effective.
In fact, most topical flea treatments actually work far better on dirty dogs, as there’s plenty of oil in their skin and coat to help absorb and move the flea treatment around effectively. You can read more about how this works, in this guide.

Alternatives to flea treatment that won’t wash off
Of course, you could switch to an alternative flea treatment that doesn’t need you to think about the perils of bathing and showering.
Many owners will give their dog an oral flea treatment. I appreciate not all dogs like taking tablets, but it won’t be affected by bathing and pills are said to be more effective than a topical spot-on treatment.
Another alternative is a tick and flea collar. We actually double-up the topical spot-on liquid with a flea collar; primarily because our dog is at risk of ticks due to walking daily in a forest environment.
Here are some links on Amazon to both flea tablets and the popular Seresto collar.