Older "Feral" Outside Female Tortiose Shell Color Cat

I have a beautiful female Tortiose cat, age unknown; I am suspecting she is older than 7 years.  She started anal light blood drops this morning when I checked on her.  She is came from a nearby neighborhood housing addition that has a "Feral Community"  Apparently, these are people who "supposedly" take care of outside wild feral cats by feeding, water and Animal Control sponsored support with very minimal medical care and spay and neuter.  Sadly, they clipped the top of one of her ears indicating she has been spayed.  To me this is criminal because it is disfiguring and the ASPCA should be notified so they can so the Animal Control for animal cruelty.  I am worried about the bleeding being my fault because yesterday I administered a dose of (Hartz First Defense) flea treatment.  Could that have caused this rectal bleeding?  I purchased this on Amazon; I did give one treatment each to my indoor cats, another 1 year old tortiose and a shorthair 6 year old cat.  They are not suffering from the same symtoms (anal blood drops)  What concerns me, is if the Hartz First Defense could be defective and, of so I will file legal action against Hartz and Amazon if she dies!View media item 372952

Can you get her to a vet?

I've never heard of that as a symptom.  It may simply be that she's constipated.  Sometimes that happens, but there shouldn't be MUCH blood, and it would only be fresh.  Is she scooting or do you see her seeming to strain to go to the bathroom?

BTW, every Trap, Neuter and Release organization I have every known has clipped or notched an ear so they know if that cat gets trapped again to immediately release it out of the trap.  It's  done while they are under anesthesia for the neutering. 

Hartz has had many many complaints against them. Google for more info. But I've never heard of anal bleeding being mentioned as a side effect of their products. It's most likely worms or something like that. Will your vet do a fecal exam without seeing the cat? That might be the least stressful way to do it.

And, yes, while I would normally be against eartipping, it's really a necessary evil. It saves the cats from being killed at a shelter or having to be "spayed" again. It would be much worse to put a cat through being cut open again because nobody could tell she was spayed. But if you have an alternate idea on how to identify which feral cats are spayed we'd all like to hear it!

Plus the ASPCA wouldn't get involved anyway---many people cut their dog's ears for cosmetic reasons, which of course I'm very much against. . .but it's not yet illegal in the US. So they definitely aren't going to object to ear cutting done for a better reason.

It stopped, I called my sister a Vet, she says constipation.