I'm sorry your cats are suffering from this issue, which can cause a lot of discomfort and is frustrating for owner and cats alike.
When it comes to flea treatment, not all are created equal. Though you have undoubtedly paid good money for the products that you have purchased, they are unlikely to be effective if they are not prescription products you have bought from the vet. Flea bombs, shampoos, collars, store-bought tablets etc are rarely strong enough to eliminate the issue.
Frontline spot-on can be purchased from a supermarket and is effective in some but we are seeing a lot of resistance issues in recent years, meaning many fleas are no longer affected by it.
Non-prescription products bought online, from pet stores or from supermarkets are generally not strong enough to tackle the issue. They may kill some fleas but not all of them, meaning the fleas never go away.
We absolutely need to use a prescription treatment to deal with this issue. A spot-on such as Advocate or Prinovox is ideal. You will need to see your vet to be prescribed these products, but I can guarantee it is worth it. If you opt for a spot-on, remember they must stay dry for 1 day before and 2 days after to ensure it is effective.
Of course, any other cats, dogs or rabbits in contact with you own will also need to be treated. The 3 cats that are affected should ideally be treated on the same day.
Similarly, as 95% of the flea burden live off the cats and in their environment, we need to treat the home on the same day as the cats. This means hot washing any bedding and blankets over 60'c, hoovering all around (focusing on dark/warm areas such as under sofas and behind curtains) and ideally using a flea spray such as RIP or Indorex. If this is not done, the fleas will just jump back on at any opportunity they have.
As fleas carry tapeworm, most cats who have fleas will also have tapeworms. Ensure they are up to date with a good quality wormer such as Droncit or Panacur.
If their skin is irritated/scabby or infected, they may well need additional therapy such as antibiotics. Hopefully this is not the case.
It has been a pleasure helping you out today, and I hope that you feel I have earned a five-star rating. Please remember to rate the service by selecting the stars at the top of the screen, otherwise the website will not compensate me for my time. There is no extra charge for this (it’s included in your question fee). Even after rating, you are more than welcome to continue asking questions. Thank you, ***** *****