What to Do When Your Newly Adopted Rescue Cat Won't Use the Litter Box, According to a Vet

It is common for rescue cats to stop using the litter box after being brought into a new home.

If a rescue cat isn't using the litter box, how long should you wait and see? We will explain the causes and countermeasures for when a rescue cat does not use the litter box in detail.

Causes of a rescue cat not using the litter box

It is common for rescue cats to stop using the litter box shortly after arriving at your home. There are three possible reasons why they may not be using it, which we will explain below.

High anxiety

Rescue cats experience significant anxiety right after they are brought home.

Cats have a natural instinct to finish eliminating and leave the area as quickly as possible because they are vulnerable during the process. Cats under high stress tend to hold it in to avoid being seen in such a defenseless state.

They don't like the litter box

Since the ancestors of cats lived in deserts, they instinctively prefer to eliminate where there is sand. Litter comes in various sizes and materials, and individual preferences vary.

Also, the box must be large enough. If the litter box doesn't meet the cat's preferences, they may hold it in.

They have cystitis or constipation

When cats are under high stress, they can develop idiopathic cystitis, which is believed to be linked to stress. Because cystitis causes pain during urination, they will try to avoid using the box. Furthermore, if blood in the urine caused by cystitis creates a blockage in the urethra, the cat will become unable to urinate at all.

If a cat is highly stressed, they may not eat or drink enough. This reduces the water content in their stool, leading to constipation and difficulty defecating.

Countermeasures when they won't use the litter box

While solutions depend on the cause, you must first ensure the rescue cat's living environment is appropriate. Here are the countermeasures for each situation.

When they are highly anxious

For a while after arriving, your rescue cat will be in a state of high tension. Let them spend their first two weeks in a cage to gradually get them used to their new surroundings. It is best to choose a quiet location for the cage. Additionally, since they are hypersensitive to stimuli like noise, using a towel to cover the cage can help them feel more at ease.

Even after they are allowed out of the cage, the litter box should be placed in a spot where people rarely walk by.

From a veterinary perspective, the ideal number of litter boxes is at least the number of cats plus one. You should have one in their primary living area, and others in hallways or rooms that are not frequently used. Using a hooded litter box may also be helpful.

When they don't like the litter box

Are you aware of the issue where stray cats use park sandboxes as toilets?

Because cat ancestors lived in deserts, they have an instinctual desire to use sand as a toilet. It is easy to understand their preference if you imagine the sand in a park sandbox; cats generally prefer litter with fine, sand-like particles.

Also, cats cover their waste with sand after using the box to hide the smell. Because of this, it is known that they also prefer litter with high deodorizing effects.

Types of cat litter include mineral, paper, wood, tofu, and silica gel. Each has different particle sizes, clumping abilities, and deodorizing effects. If your rescue cat is not using the box, we recommend trying a few different types of sand. Change the sand in each box to observe which one they are more likely to use. However, as a veterinarian, I do not recommend tofu litter, as cats often try to eat it.

Regarding the depth of the litter, at least 5 centimeters from the bottom is ideal. Anything less than 5 centimeters prevents them from covering their waste properly, which often leads cats to avoid using the box.

The size of the box is another factor that determines if a cat will like it. The ideal size for a cat's litter box is said to be 1.5 times the length of their body. This size allows the cat to enter the box, turn around, and not have any part of them hanging off the edge.

Have you ever seen videos of cats using the litter box with their upper body sticking out or their paws resting on the rim? While treated as "funny cat" content, this is actually the cat's way of telling you that the box is not the right size. It is necessary to provide a sufficiently large litter box.

As for hooded boxes, I mentioned earlier that they are good for anxious cats. However, since odors can get trapped inside, cats may also tend to avoid them. It is best not to make every single box a hooded one, but rather to have at least one hooded box among the others you provide.

Furthermore, cats do not want to use a dirty toilet. Cleaning the litter box every day is also essential.

When they have cystitis or constipation

When a cat has cystitis or constipation, they may take the elimination posture in the box but nothing comes out. Going to the litter box repeatedly, meowing while in the elimination posture, or doing the same actions outside of the litter box are also signs to look for.

If you see these behaviors, go to an animal hospital immediately. It could be life-threatening. Do not attempt to diagnose the situation yourself.

Cystitis and constipation require not just an improved litter environment, but potentially a change to a therapeutic diet and ensuring fresh drinking water is always available. You must follow the veterinarian's instructions, as oral medication may also be necessary.

How long should you wait? When should you visit the vet?

When a rescue cat doesn't use the litter box, it's hard to decide how long you should watch and wait. I recommend checking for the presence of symptoms as a guide.

If there are symptoms of cystitis or constipation, go to an animal hospital immediately.

If there are no symptoms, but they still don't use the box for more than a day after you have improved the litter environment, you need to see a vet.

If you are unsure, consult your animal hospital.

Summary

If your rescue cat is not using the litter box, you must first review the litter environment. In most cases, making these adjustments will lead to improvement.

However, since there are times when they cannot use the box due to illness, do not wait too long; consult a vet early.