Vets warn: Keep your cat indoors in March.

The real reason goes deeper than many people realise.

With the first mild days, gardens, parks and fields come back to life. While many owners want to give their cats more freedom again, specialists are sounding the alarm: early spring is a sensitive period - for wildlife, and for domestic cats themselves. Letting your cat roam without limits in March and April often harms nature without you meaning to, and also exposes your own pet to extra risks.

Why spring is such a sensitive time for cats

Between March and April, nature is working flat out behind the scenes. Many songbirds start nesting, and small mammals such as mice and shrews raise their first young. Young animals are everywhere - close to the ground, in shrubs or hedgerows - and they are often inexperienced, slow and easy to catch.

For a cat, that can feel like an all-you-can-eat buffet. Even calm, laid-back pets can switch instantly into hunting mode as soon as they spot fluttering wings or twitching movement. A cat’s prey drive has little to do with whether it has eaten - it is deeply rooted in its behaviour.

Between March and April, a particularly high number of inexperienced young animals encounter fully trained hunters on four paws - a dangerous combination for biodiversity.

European studies have been showing for years how much pressure breeding birds face in agricultural landscapes. Habitat loss and pesticides take their toll, and many populations have shrunk markedly. Add intense hunting pressure from domestic cats, and sensitive species can quickly be pushed to their limits.

How hard cats really hit bird populations

People often say, "My cat only brings back a mouse now and then." The figures suggest otherwise. In countries with lots of outdoor cats, biologists estimate that domestic cats kill hundreds of millions of small animals each year - especially birds and mice. Individual owners see only a fraction of this, because many prey animals are not brought home at all; they are eaten on the spot or left behind.

• Young birds often sit on the ground or on low branches - easy prey.
• Many species nest near the ground, for example in hedges or grassland.
• In spring, parent birds frequently forage on the ground and can end up quite literally under a cat’s paws.

So if you leave the patio door open for your cat throughout March and April, you increase pressure at exactly the time when already-weakened populations are most vulnerable. Every reduction in hunting helps more young animals survive.

Why keeping your cat indoors more often helps your cat too

Veterinarians do not recommend restraint only for conservation reasons. Spring brings several additional hazards for cats that roam freely outdoors.

More traffic, more accidents

As the weather improves, more people are out in cars, on bicycles and on motorbikes. Cats cross roads more often, chase beyond property boundaries and are more easily caught off guard. Collisions are especially common at dusk, and they can be fatal or lead to costly surgery.

More territorial fights and disease

Other cats are also much more active at this time of year. Territorial disputes increase, and toms fight over territory or receptive females. Bites and scratches can become infected quickly, and infections can spread through wounds or saliva, for example:

• Feline immunodeficiency (cat AIDS)
• Feline leukaemia
• Abscesses caused by bacteria
• Parasites such as fleas and ticks

If your cat spends more time indoors during this phase, the likelihood of these clashes drops - along with vet bills and stress for your pet.

How indoor cats can get through March without losing the plot

Many owners worry their cat will be miserable if it cannot go out as usual in spring. Vets and behaviour advisers offer reassurance - as long as one condition is met: the home needs to become more interesting.

Engagement instead of boredom

To stay content, a cat typically needs three things: activities, places to retreat, and opportunities to watch the world. If you take these seriously, you can get through the critical spring weeks just fine.

Need	Possible solution indoors
Hunting instinct	Wand toys, hiding food, dry food in puzzle feeders
Exercise	Scratching post, climbing shelves, short play sessions spread across the day
Viewpoint	A window perch with a cushion, a secured balcony, cat netting
Retreat	Covered beds, cardboard boxes, quiet rooms where no one crowds the cat

Consistency matters more than one big play session. Several rounds of intensive play for five to ten minutes a day often work better than a single half-hour stretch that leaves the cat completely worn out.

Why cats in the garden so often go after birds

Many owners are shocked when a normally affectionate cat suddenly appears at the door with a bird in its mouth. From the animal’s perspective, though, it is ordinary behaviour. Several factors feed into it:

• Movement trigger: Anything that flutters or wriggles can set off hunting instinct.
• Sense of success: After a successful hunt, the cat tends to seek out that feeling again and again.
• Territorial behaviour: The garden is treated as the cat’s own area, and “intruders” are chased.
• Hormonal factors: Unneutered animals often show stronger hunting and roaming behaviour.

Even if the cat does not eat what it catches, the outcome for the prey animal is the same. That is why many experts see owners as responsible for limiting hunting behaviour - at least during especially sensitive periods.

Practical tips: protect wildlife and your peace of mind

If you do not want to keep your cat inside all the time, a few compromises can still make a big difference.

• Limit timings: If possible, keep your cat indoors during the peak breeding period, especially at night and early in the morning. That is when many birds are most active.
• Structure the garden: Dense hedges, longer grass and shrubs give birds more cover and make hunting harder for cats.
• Consider neutering: Neutered cats usually roam less far and get into territorial fights less often.
• Use a secured balcony: If you do not have a garden, or you want to keep your cat indoors consistently, netting or screening can create a safe outdoor spot.

Many local authorities and nature conservation organisations now actively encourage keeping cats in for shorter periods during spring. In some areas with strictly protected species, there are even temporary requirements for outdoor cats to be kept indoors or on a lead. The aim is not to ban cats, but to relieve pressure on wildlife during its most vulnerable phase.

Why a few weeks of restraint can make a real difference

If you keep your cat indoors more often in March and April, you are doing more than making a token gesture. In a neighbourhood, lots of individual choices add up to a measurable effect: more young birds make it through their first weeks, and fewer cats end up at the vet after accidents.

For owners, the main takeaway is simple: a change of mindset. Cats do not have to go outside at every time of day and in every kind of weather to be happy. A well-designed indoor environment, regular play routines and a little patience are often enough for your four-legged companion to purr contentedly - while outside, blackbirds, tits and the rest can raise their young in peace.