Would reapplying flea medication 2 weeks before the next dose be more effective in killing the fleas for a severe case?

Original Question: My three dogs and three cats have the fleas. I applied a dose of revolution on Saturday but I have read depending on the severity you can re-apply another dose two weeks later? Also, what spray can I buy (will need lots) to spray on floors and surfaces (I do not have carpets). I have already bagged bedding and using the dryer to help kill fleas on sheets, etc. HELP. - Emily

Would reapplying flea medication 2 weeks before the next dose be more effective in killing the fleas for a severe case? Nov 22, 2017

Hi Emily,

I really like this question. Revolution will absolutely resolve the flea infestation but you have to understand how it works and why. You also need to understand the life cycle of the flea to know why failures can happen.

The first thing to understand is that the fleas you see on your dog are only 10% of the problem. 90% of the fleas are in the more juvenile forms of larvae and eggs which are present around your home. The fleas you’re seeing are only the adults. There are waves of hatching eggs and growing larvae coming up right behind them that will jump on your dog once they reach adulthood.

These medications largely kill the adults. If you apply one dose, then you’ll kill the fleas on your dog but this will not resolve the issue because of the presence of the maturing fleas throughout your home. You can wash everything, spray every surface and vacuum, but you will not get rid of all of the larvae and eggs in your home. And even if only a few survive, they will ensure that your dog becomes re-infected.

The medication is completely reliable and will not only resolve the issue on your dog but also in your home. The only way that they work is by applying them multiple times over a period of time. Most veterinarians recommend an application once a month for 3 months. The first dose will kill the adults currently on your dog. The second dose will kill the adult fleas that grew from the larvae and eggs in your home. The third dose is to be certain that success is achieved. I have never seen this fail with these medications. Giving one dose is absolutely guaranteed to fail because the fleas in juvenile form in the environment will simply jump back on your dog when they mature.

In a case where the 3 applications actually fail, there are causes but they are rare. The most common would be a source of fleas from another animal that your dog is coming in contact with that keeps spreading fleas to your dog. You could be petting a neighborhood dog on a consistent basis and fleas are attaching to you and you’re bringing them home but this would be extremely uncommon. In cases where this medication fails after following this protocol, I would call the company and you’ll find that they are extremely helpful in recording and resolving your issue.

I hope this helps and good luck.

Dr. Clayton Greenway

Disclaimer: healthcareforpets.com and its team of veterinarians and clinicians do not endorse any products, services, or recommended advice. All advice presented by our veterinarians, clinicians, tools, resources, etc is not meant to replace a regular physical exam and consultation with your primary veterinarian or other clinicians. We always encourage you to seek medical advice from your regular veterinarian.

Related Q&A

  • Could revolution for dogs have caused an allergic reaction in my puppy?
  • Answered by: Dr. Alex Avery, BVSc
  • May 15, 2019
  • Are flea and tick medications safe for dogs?
  • Answered by: Dr. Alex Avery, BVSc
  • May 15, 2019
  • How often should I give my dog heartworm medicine?
  • Answered by: Dr. Alex Avery
  • Jan 28, 2019
  • What are the side effects of Propalin and Stilbestrol for dogs?
  • Answered by: Dr. Alex Avery
  • Jan 28, 2019
  • Can I give my dog Benadryl for anxiety?
  • Answered by: Dr. Alex Avery
  • Jan 28, 2019
Question & AnswerQ&A
Subscribe To Our Newsletter
Be the first to get the latest pet health news and exclusive content straight to your inbox.
Stay Updated
Give it a try, you can unsubscribe anytime.