Our dog gets really messy and not a week goes by without us having to shower or bath him. The fact we live near a forest doesn’t help as he’s constantly in and out of mud baths. This also increase the risk of fleas and ticks, meaning we have to be really on top of his flea medicine.
Last week it was his monthly flea treatment date. Given our dog’s propensity for needing a bath, it did make me wonder whether it was ok to put the flea medicine on after he’d been bathed…. plus, whether a bath could even wash flea medicine off.
I decided to research into it, checking out what all the top flea treatment brands have to say about putting flea medicine on your dog after a bath. And if you can, how soon can you apply it, or do you need to reapply it?
Here’s the short answer according to my own online research, followed by the what the individual flea treatment manufacturers say:
Can you put flea medicine on a dog after a bath? You should not put flea medicine treatment on a dog right after a bath. 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.
When you bath your dog, and especially when you use a doggy shampoo, their natural oils in their coat will be removed. Topical flea treatments use your dog’s natural skin oils to move around their body to be effective – this is why you only need to spot the treatment between a small dog’s shoulder blades.
How soon can you put flea medicine on a dog after a bath?
Vets estimate that it can take as long as 3 days after a bath for the oils in a dog’s skin to be replenished.
After this period of time, you can then put flea medicine on their coat, as the natural oils should be enough after 3 days to help carry the treatment around the dog’s coat.
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.
Having said that, most people seem to agree that 48 hours is a good rule of thumb to follow when applying flea medicine after a dog’s bath.
Do you have to reapply flea treatment after bath?
As a general rule of thumbs, when you apply flea medicine to your dog you should wait for 48 hours before you let them get wet. After 2 days, providing they have the natural oils in their coat, the treatment should have started to work effectively.
The only time you might want to reapply flea treatment after a bath would be if you had to clean your dog inside of 48 hours from the application point.
Will a bath wash off flea medicine?
But what 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.
What the flea treatment manufacturers say
I took a look at the most popular brands of dog flea medicine to see what they say on their websites about treatments washing off in baths. Here’s what they say…
Can I put Frontline on my dog after a bath?
Frontline is one of the most popular brands of flea treatment and say this in their packaging about application after a bath.
“If FRONTLINE Plus is to be applied after a bath, make sure your pet is completely dry before application.”
I would disagree with that given what I’ve now researched and the 48-hour rule. But what about before having a bath or getting wet?
“FRONTLINE Plus remains effective for 30 days, even if your pet swims or is bathed. After application, keep your pet from getting wet for 24 hours.”
Can I apply Advantage after bathing my dog?
Advantage are another leading flea treatment brand, and they say this about bathing a dog after Advantage flea treatment.
“It’s recommended that you avoid bathing your dog for at least two days after treatment with the Advantage flea medicine.”
How soon after a bath can I put advantage on my dog?
Like the advice I’ve given, Advantage also believe that the 2-day rule for applying flea treatment should be observed after a bath:
“If you’ve recently bathed your dog, it’s recommended you wait at least two days before treating them with Advantage flea drops.”
The Advantage website goes on to say that their flea treatment absorbs into the waterproof layer of a dog’s skin. I assume by this they mean the natural oils in the coat. They explain that the flea treatment will be waterproof even in heavy rain and swimming.
However, they do place a slight caveat in their FAQs when they 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.”
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.
To conclude, when it comes to putting flea medicine on your dog and how a bath can affect it, 48 hours either side of getting wet seems to be decent barometer to follow.
And even if your dog does get a little wet inside of the first 48 hours of applying flea treatment, I would not worry too much. A little bit of rain will probably not do any harm, so unless your dog gets completely drenched in the first 2 days after application, there should be no need to reapply the treatment again.
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