Cat peed blood after switching to grain-free 4health

Last night my 3-year-old tortie girl peed on the floor a little. I wiped it up and was shocked to see it was blood.

I'm really curious if the cause could be related to her food. I've been feeding 4health, dry in the morning and wet at night. I've been happy with 4health because it made her poo and coat better. I recently decided to try the grain-free 4health dry food, and she has been eating it for breakfast for a week along with her usual wet food at night. I'm reading the threads here about male cats having urinary problems on grain-free food...maybe not so much from lack of grains but from what is in it, and grain-free 4health is whitefish & potato. I'm not sure if this could be related to the bloody urine at all - my cat is a girl, and it's only been a week! Coincidence maybe?

I'm taking her to the vet tomorrow.

   I am not familiar with that brand,  but there have been other people on here who told about cats getting urinary problems on grain free dry food,   and it was thought it might be due to the high mineral level in the food   I think more so when they were on all dry,  but even with half dry,  it might mean  not getting enough water for the amount of minerals?    Fish can sometimes mean too high in phosphorus.  

  I would consider switching back to just the wet food since she is experiencing urinary inflammation.

I'm going to feed wet only until this is over. She is not happy right now without her kibble, but I'd consider wet only from now on if that is what it takes.

I'm assuming even on a wet-only diet she'll still need to go in for tests tomorrow. I am so worried!

 Yes,  I  agree,  I do think I'd take her to the vet  .  

Female cats don't tend to get blockages,  but they can get inflammation / cystitis.

  Cats'  urinary problems are seldom a real bacterial infection,  so antibiotics are not usually needed   but pain medicine might be helpful,  and keeping her on a diet with plenty of fluid. 

If it turns out she has developed a lot of crystals the vet might want to put her on a temporary diet to dissolve them.  

If you have been reading those threads you might have seen a link to this article about feline urinary tract health.  http://www.catinfo.org/?link=urinarytracthealth

In addition to a wet diet ,  Dr Pierson suggested keeping phosphorus under 1.2% of dry matter .   She has a chart on her site with information about a lot of cat foods that includes phosphorus amounts.  ( mostly U.S. brands ,  so I don't know if that is useful to you or not.)

  It's kind of a balancing act,  because you don't want high carbs either. 

Hope she will feel much better soon.