In this column veterinarian Dr Liesel van der Merwe provides practical assistance for common problems in companion animals. She is a specialist physician at the Onderstepoort animal teaching hospital and a senior lecturer in the section of small animal medicine. Send your questions to This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Dr Liesel van der Merwe

Oh the lovely rich pungent smell of cat urine as you open your front door after a long day at work. Cats urinate in the house for two basic reasons: a bladder inflammation (cystitis) or due to behavioural stimuli.

Bladder inflammation can be due to bacterial infection, bladder stones or nerve-induced inflammation due to stress. Affected cats strain to urinate, often vocalise whilst attempting to pass urine and will also lick under the tail. Luckily they often urinate small volumes of blood-stained urine inside the house, usually in the bath, shower or kitchen sink, almost as if they want to show their owners that there is a problem. Take your cat to the vet to determine which of the underlying causes is to blame.

Behavioural urination can be due to territorial behaviour or stress and anxiety. Urine marking is a method by which cats interact socially. Normal urination occurs in a squatting position whereas spraying occurs against a vertical surface while the cat is standing with its tail upright.

Scent marking helps avoid direct confrontation between cats from different households who share the same territorial space. Most cats will spray at the periphery of their territory but leave the centre, your home, alone.

Territorial spraying is minimised if cats, especially males, are sterilised. The mating season become much less “fraught” for all concerned. Neutered males and females may spray or urinate in the normal squatting position in abnormal areas when feeling anxious or threatened. Inter-cat stress in multi-cat households and challenges by other unfamiliar cats coming into the home may cause this anxiety.

So how does one stop it? Try to identify and eliminate the cause. If other cats are coming into the house, I suggest an all-in-all-out policy: all cats out during the day with no access to the house when you are not there; free access when you are there; all cats in with no way out at night when you are sleeping. If your cat is being bullied by other cats, keep all cats in with no free access, unless you are at home. This may only be necessary for a couple of weeks to break the cycle of behaviour, to get you through spring or the arrival of a new cat in the neighbourhood.

Feline anxiety in a multi-cat household can be reduced by ensuring that sufficient food and water bowls and litter trays are available in separate areas of the house. Have one more of each than the number of cats in the household. Place your cats’ food bowl or bed near a favourite elimination site as they will not mess where they eat and sleep. Punishment does not help as it increases the cat’s anxiety levels.

Various commercial products can deter your cat from its favourite spraying area. These only help if the underlying cause is being managed and if the area is properly cleaned. A feline pheromone Feliway®, available as a spray and an aerosoliser, has a calming effect and can be used as part of a control program.

Remove the scent marks, especially of strange cats, both for your own and your cats’ peace of mind.

The urine of male cats is more pungent than that of females and has a fatty ingredient which allows it to adhere to surfaces. Once the urine has been wiped up you need to wash the area with an enzymatic or biological washing powder to remove all fatty residues. A final brush with alcohol will remove the last vestiges of fat.