Vetguard's active ingredient is Permethrin. My only caution would be if you have cats, keep this product away from your cats. Permethrin can be deadly for cats. Permethrin is one of the two ingredients in Advantix. I have a cat and am not comfortable having these products in the house. (I did use a permethrin based insecticide on my horses, but they had minimal contact with my cat.)

I prefer fipronil based products for my dogs, ie Frontline or its generics, fiproguard and others.

Since your dog is suffering from fleas, you need to get her on some kind of flea protection. If you have no cats, I'd go ahead and use the vetguard. Good luck.