Have Cat Questions? Ask a Cat Vet Online.
Hi, this is Dr. Hill. Spot on is not very effective and some cats can have a reaction. Your best option is to buy a Seresto collar on Amazon or Chewy.com. They are very effective (use them on my own cats). Are safe because no real toxicity and are breakaway collars. Plus they are the most cost effective because they last 8 months!!! Love them. Typically around $45 online for 8 months. It will take up to three months to completely clear the fleas from the home environment once the collar is place, which is the case with any product. Make sure to have your cat treated for tapeworms in about three months once the fleas are eradicated. Feel free to ask any additional questions. Take care.