If an infection in the urine hasn't been detected she could have chronic idopathic cystitis. The symptoms include litter box aversion, straining, and possibly blood in the urine. Treatment can include a diet change, elavil, and cosequin DS for cats. I would recommend considering a diet change to Walthams SO formula as it has marked improvements in this condition as well as increasing the amount of canned food even to the point of eliminating dry food altogether. Repeating a urinalysis will help to determine whether infection is present, if changes have occurred in the protein, specific gravity, pH or if crystals are present. Elevated protein can be seen when infection and blood are present as well as if kidney disease may be involved. I highly recommend bloodwork to determine the cause of her weightloss as I believe these may be unrelated unless bladder cancer is present. An xray of the abdomen should be done to rule out the presence of kidney or bladder stones that could be the reason for persistent blood in the urine. If all bloodwork comes back clean then an abdominal ultrasound of the bladder should be done to determine if neoplasia is present. Bloodwork will really be beneficial in her case as with a cat her age several conditions come to mind that can result in weight loss, like kidney failure, liver disease, and thyroid disorders to name a few. Hyperthyroidism is a very very common ailment in older cats and with her weightloss and poor coat quality this is a very strong possibility. It is easily treated with daily medications to reverse the condition. Other symptoms include increased appetite, vomiting, diarrhea, increased heart rate, potential murmur, and hypertension. Not all symptoms need to be present for this condition to occur. Early renal disease is also a possibility. This usually presents gradually with increased urination and thirst, decreased appetite, vomiting, etc. Damage to the kidneys doesn't show up in bloodwork until they have lost over 70% function, but the urine can detect it slightly earlier. If this condition is highly suspect considering SQ fluids and canned food or low protein foods would be recommended.

Good luck

Theresa