Keep the Litter Box Odour to a Minimum With These Vet-Approved Tips

The best way to keep odour to a minimum is to clean the litter box consistently and as frequently as possible, said Rachel Barrack, DVM, CVA, CVCH and founder of concierge practice, Animal Acupuncture. "Scoop at least twice per day," LaFontaine said. "By removing the liquids and the solids in the pan, you're removing the source of the odour. You're also keeping your cat happily using the pan. The only thing that can smell worse than a dirty litter box is the smell when a cat starts refusing to use the litter box." Jennifer Coates, DVM, serves on the advisory board for Cat Life Today, explained that the more urine and feces in the box, the more it's going to smell. "Also, the smells associated with urine get worse over time as bacteria start to break it down," she said.

Experts advise adding litter to the box after each time you scoop to replenish what you've removed. "Don't raise the overall depth of the litter as cats prefer their litter to be a bit shallower than you might think," LaFontaine said. Dr. Barrack noted that the ideal litter height is two to four inches, or more for cats who like to scratch to the bottom. She also stressed the importance of changing the litter out in the box. "Generally, I suggest replacing litter about twice a week, but if you clean the box daily and use clumping litter, you may be able to wait until once a week or every other week to replace it," she said. This will help prevent odour build-up. "A very thick layer of clumping cat litter will help prevent urine from reaching the bottom of the box where the odour can be hard to remove," Dr. Coates said.

Experts advise to wash the litter box on a regular schedule to eliminate odour that could be building up in the box — some urine and feces can get stuck to the sides or bottom, says Dr. Coates. "Thoroughly washing and then disinfecting with a bleach solution physically removes waste and kills bacteria, keeping smells and illness-causing microbes to a minimum," LaFontaine said. "If you have clumping litter, clean at least once every two weeks. If you have traditional non-clumping litter, aim to thoroughly wash and dry the pan once a week." Dr. Barrack also recommends cleaning the scooper whenever you clean the box.

Changing the litter box helps to maintain optimal hygiene. "You should replace the litter box about once per year," Dr. Barrack said. "Over time, your cats may scratch the box and bacteria can hide in these scratches causing it to smell, meaning replacement is the best option."

The size of the litter box can play a role in litter box odour. Dr. Barrack recommends getting a box that is bigger than your cat. "A box that is too small means your cat will not have enough personal space and may leave feces in places they shouldn't, including next to the box," she said. Additionally, "A larger box could help with odours by potentially reducing the chances that urine or feces would become stuck on the sides or bottom," Dr. Coates added. This is because a large box has more litter; therefore, more liquids will be absorbed and solids will be covered, LaFontaine explained.

Having multiple boxes helps to keep odours under control. "Always have at least one more litter box in your home than the number of cats who live there," Dr. Coates said, noting that it also takes some of the pressure of owners when it comes to scooping. "Ideally, we'd come in right behind our cats and clean out their boxes, but that's not really feasible," she said. "By having several boxes, particularly in multi-cat households, each should remain relatively clean in between scoopings."

People often place litter boxes in laundry rooms or cold, dark basements, which are some of the worst areas for a litter box in terms of odour control, LaFontaine said. Dr. Barrack emphasised the importance of placing litter boxes in areas that have air movement. "You don't want to put a box in a small, enclosed area," she said. "A larger, well-ventilated area is best for both combating odour and for helping your cat feel comfortable and happy." LaFontaine also explained how cat's preferences need to be taken into consideration with regard to placement of the litter box. "Litter boxes need to be placed where the cats like to go," she said. "Just because you'd like the box to be in the attic, doesn't mean your cat will be comfortable going there to toilet." Additionally, if you have a multi-cat household, Dr. Barrack recommends keeping the boxes in different locations around the house for each cat.

"Baking soda can be used as a deodourizer to help keep the litter box smelling fresher," Dr. Barrack said. This is because bicarbonate of soda neutralises acids that are responsible for many unpleasant smells, Dr. Coates added. You should sprinkle some bicarbonate of soda on the bottom of your freshly cleaned litter box, then add new litter on top. "As your cat digs around the box, she'll mix a little bicarbonate of soda into the litter as she goes," LaFontaine said. "You can add a little more fresh bicarbonate of soda every time you scoop, too."

Deodourizers can be tricky as they may discourage your cat from using the litter box. That said, they can work if your cat likes them, according to Dr. Barrack said. But bear in mind that they merely mask the smell — not eliminate it. "The scent tends to dissipate rather quickly, negating any odour-hiding benefits," LaFontaine said. "Moreover, cats have a far more sensitive sense of smell than we do and might find the perfume-y smell offencive."