One of the reasons that cats are popular companion animals is that they are clean.
When compared to dogs, most cats require little, if any, toilet training.
As my colleague veterinary behaviour specialist Sarah Heath wrote in the Journal of Feline Medicine and Surgery, "the ability of cats to reliably use litter facilities provided within the home makes it easy for owners to go out to work and spend time on their leisure pursuits without worrying about whether the cat is desperate to toilet."(Heath, 2019)
Yet one of the common problems encountered by veterinarians is the cat who urinates outside of the litter tray.
This is very distressing for owners, who don't appreciate cleaning up after their cat.
So, why might a toilet trained cat urinate outside of their litter tray?
One reason is the presence of an underlying physical condition.
Urinary tract infections or inflammation can cause painful urination, which may cause cats to associate the litter tray with a painful experience.
Some cats develop stones in their urinary tract (uroliths).
Other painful conditions like arthritis may create a similar negative association, or make it difficult for cats to climb into a tray.
Diseases that cause a marked increase in thirst, such as diabetes and kidney disease, increase urine volume.
For this reason, it is important to consult a veterinarian to rule out a medical cause.
Your veterinarian will perform a physical examination and potentially urine and blood tests.
In some cases, additional tests including imaging are required.
Diagnosis and appropriate treatment may resolve the problem.
Another reason for house soiling is territorial marking.
Even entirely indoor cats may feel threatened by other animals in the household, human household members (including those that are over-exuberant in showing affection to cats), or cats outside of the household.
My own cat Hero once urinated around the house in response to a neighbour's cat looking through the window at night.
Cats have specific preferences about litter trays - as humans do about their own latrines.
If cats are forced to share a tray, trays aren't cleaned appropriately, or the trays are positioned in a site where cats are not afforded privacy, they may avoid them altogether.
Every case requires individual trouble shooting.
It is not uncommon for me to chat to an owner and find out that their cat began urinating outside of the litter tray when the litter tray was moved, another cat was introduced, a new baby arrived in the household, renovations began or the type of litter used was changed.
You can assist your veterinarian by telling them when your cat began to urinate outside of the litter tray, the number of animals in the household and how they behave towards each other.
It is also important to mention the location and types of litter trays available, the type of litter used (and whether this has changed) and the location of other critical resources in the household.
From a cat's perspective, critical resources include food, water, favourite sleeping places and entry and exit points.
After medical problems are ruled out, I work with owners to identify and remove stressors from a cat's environment, while ensuring that litter tray facilities are up to scratch.
I also advise owners never to clean previously soiled sites in the house with chlorine or ammonia.
While they smell better than cat urine to humans, they smell like very strong cat urine to cats - who may then be moved to mark the site with their own scent.
REFERENCE: HEATH, S. 2019. Common feline problem behaviours: Unacceptable indoor elimination. Journal of Feline Medicine and Surgery, 21, 199-208
Dr Anne Quain BVSc (Hons), MANZCVS (Animal Welfare), Dip ECAWBM (AWSEL) is a lecturer at the Sydney School of Veterinary Science and a practising veterinarian.