blood in the litter box

Question
I have three cats, one neutered male, 2+ yrs., one spayed female, 2+ yrs., one spayed female, 7+mos.  They get along fine, play actively, sleep well, eat well.
They each have their own dish.  I split 1/2 a 5.5 oz can Friskies between them twice a day plus they also each get about 2.5 tablespoons of Friskies dry for indoor cats.  They get the dry food 3 times a day.  They also get pinches of fat free turkey breast I share with them from my breakfast.  No more than 3 pinches per kitty.  In the evening the get a couple of Whiskas Temptations treats for tartar control.  They share a water dish which I freshen twice a day and add an ice cube since the male seems to like his water colder?!
They don't get outside except in summer and only on a lead so we can see what they are into.  They get regular checkups at the vet and this past fall the two older ones had a midlife blood screening along with their boosters.
They share a litter box (the new Breeze system) and I clean it whenever I see feces in it and change the urine pad when it looks well used.
All seems well but every now and then I find blood on the Breeze pellets.  None on the feces, none on the urine pad.  Seems thick like from a wound, no real "blobs", just several Breeze pellets globbed together by blood.
None of them seems to have a problem, though the male does "dig" in the litter box a lot and cleans his rear a lot, but these are not new behaviors.  He has always been like this.  We have had him for 1+ yrs.  I resued him from work where he had been eating out of the dumpster.  He gets regular vet care since we brought him home.
The blood has been showing up since before we got the younger cat which I brought home from a friend at Thanksgiving.  The older female we got from a shelter.  Our vet knew the people whose cat had given birth to her.
I can't think of anymore info but will gladly answer anything I can.  Thanks so much for any help.  Trying to avoid another trip to the vet if I can until I get the latest spaying paid for.

Answer
Blood on or in the stool is a sign of some sort of irritation in the colon, the rectum or the anus. It can be from sores, from the entire lining becoming raw and irritated or from fissures, or cracks.

Most of the time this is a result of food irritating the area. Some cats don't do well with the food that the other cats are eating. This new kitty might have a more sensitive stomach than they have.
If you have only just begun to see it since she was brought into the house it's a good bet it's from her.

While the amounts you feed are rather small, the food you are using is not of the highest quality. You are a very good pet owner by evidenced of the way you care for these darlings, so why are you using such terrible food?

I would switch over the course of seven days, to Science Diet Sensitive stomach for all of them. It won't hurt the cats that are not affected and will help the one that is. She could need something that the other food is not giving her.

It is a completely balanced diet without excess nutrients that unfortunately, Friskies is known to have.
This food is also made to help their teeth and urinary tracts so it is perfect for the male too. The tartar control treats you are using really do nothing for their teeth. The best way to help with this blood issue is to do the switch and see if it stops. I have to say when I fed cheap food to my cats many years ago I remember many times seeing blood in the stool of my cats. I have never once, in 28 yrs, seen that since they have been on Science Diet.

I use Whiska wet myself in the morning and my cats only get a spoonful of it twice a day but they live on Science Diet Mature cat and have no dental issues or any health issues. I have a 14 yr old and a 6 yr old.

I have had cats live to be 19 on this food. I have fed and recommended it for over 28 yrs and I have never had a client return it or stop using it.

With the excellent care you give these cats you should add the most excellent food with it. Hills has over 50 yrs of veterinary research behind it and more vets feed it than any other food for a good reason.

I hope this helps some Liz. If you do switch, make sure that you do it over a 7 day period. Another thing I would do is stop the turkey because while it is fat free- deli turkey is high in sodium. Something neither cats nor we need.
If you need to feed them treats, get some Science Diet ones. My cats went bonkers over them and so did my dog!

If you have any more questions please let me know.