Thank you for your question.
There are a host of medical issues that may result in inappropriate elimination including infection, bladder stones, structural abnormalities, kidney
disease, and diabetes
Your vet has determined that she does have a UTI. UTI's create a painful burning sensation and an urgency to urinate. A cat is not mentally sophisticated enough to understand that she has an infection and the infection is causing her pain. She just knows that sometimes when she is urinating in the litter box, she experiences pain. To her, this means that maybe it's the litter box causing the discomfort. As a result, she avoids the box- this is called a litter box aversion. She's found that urinating on something soft seems to decrease the pain when she pees, and so has elected to go on the couch when she is uncomfortable.
Prior abuse is not likely to contribute to her litter box aversion. If it had, she would likely have never used the litter box since you had her.
Hopefully, your vet put her on an antibiotic and some pain medication to treat the urinary tract infection. Often, UTIs are secondary to a condition called Feline Lower Urinary Tract disease (FLUTD).
FLUTD- probably one of the most frustrating diseases affecting cats, owners, and their veterinarians.
It is one of the top reasons that cats are relinquished to shelters every year.
These cats seem to have periodic sterile (absence of infection) inflammations of the bladder wall. As a result of this, they feel an urgency to urinate and don't always make it to the litterbox. Moreover, cats begin to associate the discomfort of urination with the box itself and so then begin to develop a litter box aversion. They don't understand why they hurt, they just know that they hurt when they're in that darn box so they begin to avoid it.
FLUTD has been compared to idiopathic interstitial cystitis in women (idiopathic is a fancy way of saying unknown cause). This condition is so painful, that women will sometimes attempt suicide to be free of it.
FLUTD cats typically urinate outside the litter box, and can have any, all, or none of the following: blood in the urine, difficulty urinating, urinating small amounts frequently.
Flare-ups seem to last for 7 days or so, and usually resolve without any treatment. They may occur at any time.
Stress seems to exacerbate the symptoms of this disease, and it seems to be a little more prevalent in cats that are high strung.
Certain breeds like Persians and Himalayans seem to be slightly more predisposed to development of FLUTD but no evidence for a hereditary basis for the disease has been established.
FLUTD is managed, not cured and steps include:
-increasing water intake: canned foods
and easy access to fresh water (sometimes fountains or leaving the tap dripping).
- minimizing stress
- frequent litterbox cleaning
- sometimes the tricyclic antidepressant, amitriptyline, works because in addition to it's mood altering properties, it's also believed to have anti-inflammatory and analgesic properties.
- Cosequin- a polysulfated glycosaminoglycan, it's believed that since the lining of the bladder wall consists of similar components that supplementing with Cosequin helps the inflamed bladder repair itself. Anecdotally this seems to help, but I've not come across too much really hard evidence that it does.
Often, because both UTI's and FLUTD result in a litter box aversion, the affected cat will development a behavioral component to the inappropriate elimination. Some other things to try include:
- cleaning all soiled areas with an enzymatic cleaner such as Nature's Miracle or Anti-Icky Poo
- adding additional litter boxes. The rule of thumb is one litter box per cat plus one, so ideally you should have 2 boxes if she is your only cat.
- cats have a depth preference believe it or not. Most cats like litter to be 2 inches deep.
- unscented litter is best
- uncovered litter boxes because covered ones hold in odor
- some cats prefer to defecate in one box and urinate in another.
- dump out all litter and wash boxes in mild soap once a week
- some cats, like your girl, have a substrate preference. Since she likes the softness of the couch, sometimes lining the box beneath the litter or the wall behind the litter box, with the same substrate encourages the cat to use the box.
- behavioral altering drugs like amitriptyline or buspirone
Your cat would also benefit from a diet which modifies her urinary pH and helps to prevent crystal formation and inflammation. You can get such diets through your vet.
As frustrating as this condition is for you, it's important to remember that it is also very uncomfortable for her. However, there are things that can be done to help.