Full disclosure: I'm a cat man. Yes, they're pretty much useless and their meat is stringy, but for 25 years or so I've lived with a bunch of rescue cats that, like me, have parts missing. (an eye here, maybe an ear or tail off, or a missing foot.) Treating multiple cats or small dogs for fleas can run into some real money in a hurry with the little pre-packaged topical treatments that work best for my critters. Add the trouble of cats under 5 pounds and over 12, and now I need different doses. When I was dealing with a local cat rescue group to trap and neuter all my feral cats, I learned that they were using treatments that were safe for both dogs and cats, although in different doses based on weight. I checked with my small local pet store owner and we sat down and carefully read some labels. Finding identical ingredients in Extra Large Dog and Cat under 9 pounds we then did the math and figured out that I could get 9 cat doses out of a single extra large dog vial. (the under 9 pound dose works fine on my big cats) With the purchase of a syringe and needle for $1.00, (only for neatly drawing the doses from a needle hole under the cap in the original container.) I realized an instant savings of about $75.00. I'm not endorsing a product or saying that this is a good idea for everybody. There are dangers, you could prick your finger or something. Life is dangerous. If you're smart enough to do your own product research, find a cat and dog compatible product and develop safe dosing levels for your pets you could save some money. Saving money of flea treatment leaves more for pet preps, including future flea treatments as well as stock piling their food. If you don't think of a flea infestation as a survival issue, try entering a property that had been infested and then left vacant for a couple weeks. I've entered vacant homes where the hungry fleas covered my legs as soon as I stepped in the door. Unchecked they will slowly kill smaller cats and dogs. They're no picnic for humans either, and if you unknowingly spread than to a friends home you may become unwelcome. A good flea treatment turns cats into mobile flea killing machines, and any flea that jumps on them after treatment is a goner.