Pros: It is administered by a drop to the back of the head and between the shoulders, very easy to apply. One pipette for one normal weight cat.
Cons: It works out quite expensive when you have more than one cat and it is applied every 5 weeks.
I have been using Frontline for years. It was first administered by my vet then became available in certain pet shops in England. It is classed as a perscription drug so has to be signed for at the counter.
My cats hate the smell, though it doesn't smell too bad to me. It leaves a slight greasy residue on the fur so be careful when giving your cats a stoke after application, but this is gone in a few hours. One pipette does for a normal weight cat -between 7.5 -15 mg/kgl- so I don't have to worry too much about having to weigh them first.
The solution works on contact with the skin so no oozing into the cat's blood stream. It is applied by parting the fur and putting a drop on the back of the head and then again to a spot between the shoulder blades. A quick job, without the fighting I had to do when using a spray ( deffinetely not a good idea to use with cats) or powder. Neither worth the money or time and effort.
I very rarely find any fleas on the cats when I comb them and I haven't had any problems with fleas in my home.