Thank you for your patience. It certainly sounds like Sasha is having some relatively large blood clots in her urine off and on. There are a number of possible causes for this including urinary stones, a severe cystitis and/or urinary tract infection, or even a urinary tumor (although much less likely given her age). Blood clots in the urine typically indicate severe inflammation of the lining of the bladder which leads to bleeding, the blood then clots in the urinary environment. For such severe inflammation to occur in the bladder, urinary stones or a urinary tract infection are highly likely.
The best next step here is for a full physical exam with your local vet, along with a full urinalysis. By testing your girl's urine for it's pH as well as checking the sediment under the microscope, they will relatively quickly be able to tell if any urinary crystals are present. Likewise, a full urinary culture and sensitivity will help to rule out a urinary tract infection that could just be smoldering away and causing intermittent issues here. I would also recommend an abdominal xray or ultrasound to try and rule a urinary stone (or stones) out as the cause of her intermittent urinary bleeding.
If the blood is IN the urine, then this is very unlikely to be related to a uterine issue, but it is likely your girl is spayed anyway. If she isn't spayed, then we do have to consider whether this could be a uterine problem potentially here.
For now, definitely continue to encourage your girl to drink plenty of water. Hopefully she is doing this already, but make sure you have plenty of fresh water available for her around the house. If possible, please also feed a wet diet rather than a dry diet, to assist with this moisture intake as well. If you can get her seen first thing on Monday morning, that will be the best approach here. Do take in a fresh urine sample with you as well if you can (in a very clean container, or urine sample container if you happen to have one!). I hope all of the above makes sense? If you have more questions or if I can help in any other way, please do not hesitate to ask! If you would like to accept my answer, please press RATE OUR CONVERSATION (I am not compensated in any other way). Bonuses are always welcome. Thanks! I hope to work with you again soon!
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