Vertical enrichment: designing a home in height for your cat

The cat descends from a solitary predator that is itself prey to larger animals. Two simultaneous needs follow from that double condition: seeing without being seen, and having an escape route that does not run along the ground. A shelf at a metre and eighty satisfies both, which is why a cat with access to raised positions generally shows less reactivity to household events than one living only at floor level.

In a multi cat home, height serves a second and even more important function: it allows space to be shared without sharing the level. Two cats that dislike each other can coexist in a room if one can occupy the high band and the other the low one. Without that option the only available strategy is horizontal avoidance, which is hard in a flat and produces chronic tension.

International feline medicine guidelines organise a cat's environmental needs into five points. They are not a shopping list but a way of working out which need is unmet in a specific home, which is why they are worth reading before ordering anything.

1. A safe place to withdraw to: enclosed on several sides, raised where possible, where the cat is not disturbed. In a multi cat home more than one is required.
2. Key resources separated and in multiple locations: food, water, litter trays, scratching posts, resting places and toys should be distributed rather than clustered in one corner.
3. The chance to express predatory behaviour: short frequent play sessions that reproduce the hunting sequence and end with a catch.
4. Predictable and consistent human interaction: initiated by the cat where possible, with a style and duration that stay stable over time.
5. Respect for the sense of smell: avoid harsh detergents on marked surfaces, do not wash every bed on the same day, do not introduce strong scents into resting areas.

The practical rule that follows from the second point is the number of cats plus one: key resources should be at least as many as the cats, with one spare, placed in different locations. It applies to litter trays, to bowls and also to raised resting spots, which are resources in their own right and are contested as such.

The figures below are starting points for a healthy adult cat of medium size. They should be adapted to the individual: an older, overweight or arthritic cat needs smaller steps and deeper platforms.

The most common mistake is buying a tall scratching tower, putting it in a corner and considering vertical enrichment done. An isolated element is a destination, and destinations get little use. What cats actually use is a continuous route: a sequence of platforms that lets them cross the room without touching the floor.

• Continuity: the gap between platforms should be crossable with a step or a short hop, not with a maximum leap.
• Two exits from every platform: a shelf you can only back out of becomes a trap in a multi cat home and is abandoned after the first unpleasant encounter.
• No bottlenecks: the route must not force the cat past another cat's bowl, litter tray or bed.
• Away from slamming doors and noisy appliances: a station above the washing machine gets used only until the machine starts.
• Non slip surface: an anti slip mat or a felt pad changes perceived safety and therefore how often the spot is used.
• A view of the room entrance: cats pick places from which they can see who comes in, not the ones with the nicest view.

In households with a dog the vertical route has an additional role: it creates a zone where the cat is structurally out of reach. A high access point in every shared room, and in particular a litter tray placed where the dog cannot go, defuses many conflicts without separating the animals.

Radiographic studies in older cats have found signs of degenerative joint disease in the large majority of animals over twelve years, often in cats that were not limping and that their owners simply considered calm. Cats do not limp the way dogs do: they reduce jumping, change resting places, stop using the high level. An abandoned vertical route is therefore one of the earliest signs of pain, and should be read as such.

• Replace jumps with ramps or intermediate steps, keeping the same destination: the goal is to preserve access, not to lower expectations.
• Bring essential resources down to floor level: water, food and at least one litter tray with a low rim and front access.
• Check the resting surface: an arthritic cat avoids hard cold surfaces well before it avoids height.
• Warm the favourite resting spot: gentle warmth increases the time spent lying fully stretched.
• Note the date a station stops being used and mention it at the consultation: it is clinical information as useful as body weight.

Every environmental change should be treated as a trial with a measurable outcome, otherwise expensive unused objects pile up. Seven days and a simple observation method are enough, with no need for cameras.

1. 1

   Introduce one change at a time

   If you add three shelves and a new bed simultaneously, you will not know which of the four worked. One change per week keeps every result readable.

2. 2

   Observe at three fixed moments

   Early morning, afternoon and evening, noting where the cat is. Three observations a day for seven days are enough to tell a used station from an ignored one.

3. 3

   Make the novelty interesting without forcing it

   A treat on the shelf in the first days, the play session that ends up there, a blanket that already carries the cat's own smell. You do not carry a cat up to a new station: exploring must be its own choice.

4. 4

   If it is unused after seven days, change one factor

   In this order: height of the last step, surface of the platform, position relative to noise, presence of a second way out. The problem is almost always one of those four.

5. 5

   Rotate toys, not stations

   Prey like objects lose interest and should be alternated every few days. Resting stations, by contrast, must stay stable: moving them wipes out the habit you have just built.

A short record of which stations get used, with the dates of any change, turns out to be useful beyond this exercise: it reveals shifts in habit before they become obvious and gives the vet an objective reference when mobility or behaviour changes.