A cat on lasix will drink a lot of water and quite often, which is what we want to see. The meds drive the cat to drink. Drinking helps support kidney function; helps hydrate the body as the lasix withdraws fluids-which can lead to severe dehydration, which we want to avoid for numerous other health reasons. And the frequent drinking combined with the diuresis process from the lasix, will drive the cat to want to urinate often, sometimes large amounts, possibly every 2-4 hours. The cat will be comfortable using the box. But sometimes they may go out of the box as the urge to go so frequently may overwhelm them. Valium or Buprenex may work to ease their discomfort (search Valium to read why Myrna takes it for this very reason.)
If the cat's NOT on lasix, then you can assume there's an issue with the kidney/bladder. You may see the cat drink a lot of water and quite often as the body seeks a way to support kidney function and/or to help flush out any bacteria/crystals/inflammation in the kidney/bladder. You will see the cat urinate a few times a day if an issue is just beginning or every few minutes with increasingly small amounts of urine when a flare-up is hitting. Often, blood is in the urine. The cat may also choose to go out of the box on paper, rugs, cold floors, blankets, etc. as the box may be uncomfortable to use. You may see the cat sit in the box for a minute or longer trying to expel urine. You may see the cat push urine out, as if straining to excrete urine. The cat must see the vet or ER vet as soon as possible.
The typical protocol is for the vet to collect a urine sample by needle withdrawal so that the sample is clean. They will check for bacteria or crystals, and check the WBC (white blood cell count). A flare-up can occur if crystals formed in the bladder, irritating the bladder. Crystals can also lead to a very painful blockage in the urethra. This blockage is more dangerous for male cats than for female cats. If your male cat urinates out of the box, it must see the vet or ER vet immediately to see if there is an infection or blockage. Because a blockage can allow bacteria to enter the kidneys and cause other physical issues, often male cats will die from blockages if treatment is not sought early. If the WBC count is high, that indicates an infection. Often with only crystals in the urine, the WBC will be low. With an UTI or actual bacterial infection, the WBC will be elevated. The cat may also have a fever and will probably be in a lot of pain. IV fluids or sub q fluids should be given to help flush out the bladder. If there is an infection, pain meds and antibiotics such as Clavamox will be prescribed. Without an infection, usually the vet will give pain meds and suggest that the cat only eat SO or CD wet and dry foods, foods that promote bladder health and fight the formation of crystals and help fight formation of bacteria. The cat could also take Methigel, a urine acidifier which helps change the pH of the bladder to help prevent crystals and bacteria. For other kidney/renal/bladder issues, there are other brands of foods for these specific issues. Ask the vet which prescription cat foods might work best. Other tests that may be needed would be xrays to check for stones and an ultrasound to image the kidneys and bladder to look for other physical causes such as blockages, cancers, and for idiopathic cystitis. Idiopathic cystitis is caused by a thickened, inflamed, irritated bladder, usually without bacteria or crystals present. Pain meds to relieve the pain and the swelling and the irritation will be needed and probably a psychotropic to keep the cat calm, not only as it heals but going forward for the rest of its life. This is what Elizabeth has had since a kitten but hasn't had a flare-up in over two years. But this is what MSU believes is what she now has and not a UTI.
We had been told by the ER on Sunday that Elizabeth had a UTI, that bacteria presented in the urine sample and that the WBC was elevated. Except, it turns out, they captured the sample from the exam table and probably picked up bacteria there. AND the WBC wasn't that elevated to point to an infection-the WBC should have been much higher had she had this bad of a flare-up due to bacteria. So, after two days of urinating small bloody samples, and still doing so today, and because her regular vet couldn't see her (nor did they seem too concerned that she wasn't responding-they suggested we come back on Thursday when they do ultrasounds-THURSDAY???!!!), and because the ER didn't (in my estimation) handle this matter fully, I took her to Michigan State Vet Hospital.
After four doses of Clavamox 62.5mg on Sunday, and more antibiotics Monday, she continued to urinate tiny amounts of bloody urine. It was unusual that she was not responding to meds. We gave her plenty of Buprenex to relieve the pain and the fever but it didn't seem to help. We also gave her 12ml of water by mouth every couple of hours. We had a blanket and some washable rugs on the floor for her to use. When cats have UTIs or any flare-up that makes urinating painful, they will often choose soft fabrics and cold floors which feel more comfortable, which is what she did. That's why we also kept her isolated in a bedroom and constantly scooped the litter boxes.
At MSU, they are keeping her overnight for treatment. They gave pain meds and IV fluids. They cultured the urine; they did blood work; they did an ultrasound of the bladder. They reviewed the xrays from the ER and the ER records. The vet called to say Elizabeth is resting well with pain meds and IV fluids. She doesn't have a UTI. No bacteria in the urine sample they withdrew with a needle. The WBC in that specimen was low, too low for an actual UTI flare-up. Hence, lack of response to antibiotics. They will finish tests tomorrow; try pain meds for home and a psychotropic. They hope she will come home tomorrow if she responds to treatment.