The short answer to your questions is that no, the spray cannot be used in the same fashion as the single-dose ampules. The dose of the spray is also approximated based on body weight and does not have a well-regulated, metered dose like the ampules do. Oral flea control products, or "flea pills," are given to a cat by mouth to kill fleas and prevent fleas.

Although topical flea control products are typically easier to use (no need to convince your cat to swallow a pill), there are some cases when an oral preventive is an ideal choice among the best flea treatments for cats. For instance, some cats with sensitive skin can't tolerate a spot-on treatment. "Comfortis is one of the ones I like," Harper says. "It's harder to get the cat to take an oral product, but if you can manage it, it's a pretty effective oral flea medication. It's strictly and solely for fleas." http://npic.orst.edu/factsheets/fipronil.html#:~:text=%2D858%2D7378.-,How%20does%20fipronil%20work%3F,bind%20to%20insect%20nerve%20endingsMinimum age and weight: Cats must be above a minimum age and weight to use flea medications. For this reason, there are fewer options for young kittens. Available without a prescription, Capstar is the only flea control product safe for kittens as young as 4 weeks and weighing at least 2 pounds. Kittens must be at least 8 weeks old and sometimes older to be treated with other topical or oral flea control products. Although Frontline Plus for both dogs and cats contain the same active ingredients, there are differences in the dosage of active ingredients and inactive ingredients, so the dog products should never be shared with cats.

con icon Two crossed lines that form an 'X'. Not labeled for use in breeding, pregnant, or nursing cats If for some reason you are unsure if the product was administered correctly or whether all of it was applied, it is usually safest to not apply an additional dose. Comfortis Chewable Tablets are fast-acting and good for cats that can't tolerate topical flea preventives. Spinosad, the active ingredient in Comfortis, starts to work within 30 minutes and kills 98% of adult fleas within four hours. FRONTLINE Plus also contains the important addition of (S)-methoprene which acts as an insect growth inhibitor. (S)-methoprene works to prevent the multiplication of fleas by inhibiting the development of the immature stages of growth (eggs, larvae and pupae) for up to 6 weeks of application. Flea shampoos kill fleas that are currently on your cat, but topical and oral flea control products are far more effective. Some flea shampoos are even harmful to cats since many contain pyrethrins. "Nowadays, flea shampoos are rarely if ever needed because the topical and oral flea products are much more effective and safer," Sawyer says. "For flea-infested animals, we typically give a fast-acting oral product such as nitenpyram [Capstar] and follow with a bath in Dawn dish detergent or another mild cat shampoo. You can use a flea comb to assist in removing dead fleas and flea dirt [flea feces]."

Both ingredients found in Frontline Plus (fipronil, (S)-methoprene) generally appear to have a low potential for toxicity both topically and even if accidentally ingested. If the product really doesn’t seem to be working, there are other things to consider like application errors, bathing within 24 hours of application, etc. Comfortis is one of two oral flea control products available for cats; the other is Capstar Flea Control Tablets. Unlike Capstar, which kills fleas for only 24 hours, Comfortis protects cats against fleas for an entire month. However, Comfortis is not safe for kittens younger than 14 weeks old, while Capstar is safe for kittens as young as 4 weeks old. Water exposure, bathing or shampooing does not affect the efficacy of the product as long as it doesn’t occur more than once a week or within 2 days of application of the product.