I can appreciate that you want to quickly give your companion some relief, but many human medications are toxic to cats. Also, until you know what's causing the infection, you may be making things worse by offering a med that doesn't effect the source. For example, an antibiotic doesn't treat a virus.

Generally there are three lower urinary tract disorders in cats (not in any specific order):

FUS (Feline Urologic Syndrome), FLUTD (Feline Lower Urinary Tract Disease/Disorder) and LUTD (Lower Urinary Tract Disease/Disorder).

Early symptoms may be repeated licking of genitals, straining at the litter box, calling/meowing in pain, red or pink blood showing in urine, inappropriate urination or soiling (defecating) outside the litter box and just not acting right.

It's vital to get your cat seen as early as possible. Urine toxins and pressure can cause kidney failure in as little as 24 hours.

Most infections are ‘idiopathic cystitis', meaning there's really no identifiable cause. Other causes may be kidney stones, systemic disease, congenital abnormalities or even cancer. In cases of bladder stones, about 50% of them are struvite and 50% are calcium oxalate stones, not unusually accompanied by crystals.

Struvite (triple phosphate stones) are normal urine components that have clumped together; Calcium Oxalate stones are usually from feeding high acid, struvite-treatment diets (foods that are meant to prevent urinary problems).

The problem needs to be diagnosed by a vet who may do x-rays or ultrasound (which is usually best). Treatment will often include antibiotics and suggestions for modifying diet. Surgical intervention may be necessary, depending on clinical findings upon exam.

If urinary problems are not solved or recur, further exploration is necessary to determine what will often be a congenital abnormality.

Here is a valuable link to a vet's site discussing the necessities in a feline diet for overall best health http://www.catinfo.org/

For information about FLUTD, look here: http://www.thepetcenter.com/exa/uo.html

If you need assistance in paying for any of your companion's health care, start with these and do not give up!

http://www.imom.org/

http://www.help-a-pet.org/

http://www.uan.org/index.cfm?navid=163

http://www.animaladvocacy.net/shelters-rescues.html

http://www.lovethatcat.com/spayneuter.html

http://www.spayusa.org/

http://www.mspca.org/site/pp.asp?c=gtIUK4OSG&b=126801

Don't forget to call your local Humane Society for guidance as well. If you have a Pet Smart in town, they often have the numbers for rescue organizations that may also help, at least with recommendations for where (or who ) to go.

It's obvious you love this lucky little girl. I wish I could offer a home remedy, but as you see from the information here, it's just not that easy.

Once treated though, you may be able to avoid it ever happening again with the info offered at the link (above) for the nutritional modifications.

I hope this works out simply and quickly for you and your pet. God bless