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Indoors or outdoors? International owner demographics and decisions on the lifestyle of pet cats

05th May 2021

  •   Spotlight on Science
Indoors or outdoors? International owner demographics and decisions on the lifestyle of pet cats

Following on from last month’s Spotlight on Science, we continue with the theme of pros and cons of keeping pet cats indoor-only versus giving them outdoor access.

Dr Luciana Assis and Feline Wellbeing Panel Member Professor Daniel Mills, both from the University of Lincoln, UK, teamed up with UK cat containment company ProtectaPet® to investigate what the effects of introducing three types of outdoor containment systems were on cat welfare and owner concerns using a new feline welfare assessment tool.

iCatCare’s Head of Cat Advocacy, Sarah Ellis chatted to Luciana Assis to delve a little deeper into the research.

What was your inspiration for the study?

The issue of allowing cats outdoors is a complex debate. Some argue it’s essential that cats go out for their well-being (being an indoor only cat has been shown to be associated with a range of problems some of which might relate to stress but others to environmental contaminants). However, we know that tens of thousands of cats are killed and hundreds of thousands more injured on the roads each year in the UK alone. Using a fencing solution such as that provided by ProtectaPet®, seemed like a good solution, but we did not know whether this might be frustrating for cats, especially those used to wandering beyond their garden.  Also, most owners’ gardens are much smaller than a typical cat territory, so even for cats that had been indoors only, there could be issues. The problem was we simply had no data on this. ProtectaPet® were interested in looking at this, and the Government offered funding to help academia work with business, so there was a great opportunity for us to explore these issues.

What was the aim of the study?

Our aim was to investigate whether installing a controlled outdoor environment would affect either or both the cats’ welfare and their caregivers’ concerns about allowing them to go outside. In order to do this, we compared the level of welfare of cats and how concerned their owners were before and after installing a barrier system that allows controlled outdoor access, produced by ProtectaPet®.

How did you conduct your study?

We surveyed cat owners that were customers of ProtectaPet® barrier systems about their opinions on caring for cats and their cats’ lives. We also wanted to know about how much owners were concerned about different aspects of allowing their cats to go outside without supervision before and after installation, and whether there were changes in specific behaviours of their cats after the installation. We received a great response with over 400 respondents which we analysed in detail. Importantly, we compared cats before and after installation of ProtectaPet® solutions, that initially had unrestricted access, restricted access, or no access to the outdoors at all.

Three types of ProtectaPet were reported in the study; 1. Cat Fence Barrier, 2. Catio and 3, Cat Enclosure – can you describe the difference between these products?

The Cat Fence Barrier involves attaching a bracket to an existing fence or wall – usually at intervals of 2m – connected with mesh. The bracket is angled inwards so that a cat is prevented from climbing or jumping over the fence.

The freestanding Cat Enclosure is used where there is no pre-existing fence or wall, so posts with brackets attached to the top are installed, connected by mesh.

The Catio (cat-patio) is a cuboid structure with a mesh roof so it is totally enclosed. Everything is made with a special mesh so both air and sun can naturally flow inside.

What were your main findings?

Our main findings were:

  • Our respondents were representative of the cat owners in the UK in that the majority of cats’ owners live in an urban environment with small gardens, have multiple cats, have had a cat involved in a road traffic accident, and agree that cats who have access to outdoors have a better quality of life.
  • Before the installation: almost half of the cats either did not have access to the outdoors at all (we do not know if they had ever had outdoor access prior to this ‘before’ period) or were outdoors less than 1h per day. After the installation: all cats had outdoor access with over 98% of cats staying outside more than 1h per day.
  • The frequency of visits of other cats in their gardens was significantly reduced, which may have led to cats feeling safer in their own garden (e.g. without fighting with other cats, etc).
  • The owners’ level of concern about a range of problems associated with their cats having unrestricted access to the outside such as injury in the road and getting lost were also significantly reduced.
  • We used four welfare subscales that measured positivity (how relaxed cats were around the home and willing to play with owners), maintenance behaviours (i.e. appetite, thirst, sleeping and hunting), health issues and fearfulness, and all showed significant improvements after installation of the barriers.
  • The longer cats spent outdoors after the installation the better welfare they seemed to have.
  • Overall, installation was associated with positive changes in both owner and cat quality of life, which seems to be particularly associated with an increased sense of security.

Was there anything that surprised you?

The fact that cats who used to have unrestricted access to outdoors also showed some improvement instead of decrease in their welfare was surprising, since generally people believe restricting freedom in cats is detrimental to their welfare. This suggests that having all the space available is less positive for cats than having a limited space but safe from intruders (e.g. other cats, foxes, etc), which might stem from cats natural territoriality, in which cats constantly try to keep intruders out of their territory.

Do you have comparison data of cats who currently had unrestricted access outdoors to cats that now are within a containment system? I wonder because so many cats (nearly half) did not have access to the outdoors beyond 1 hour a day. Could the effect you see be related to outdoor access rather than contained outdoor access? It would be good to see the effects on your welfare sub-scales when comparing the subpopulation that did have outdoor access before installation of the containment system to the subpopulation that didn’t.

Unfortunately, we didn’t have a control group, so we don’t have this data but it would be an important feature for further research. 

However, wdo have a comparison between subpopulations according to their previous access to outdoors (before installation). On average, cats with unrestricted access to outdoors showed an improvement in the Health Issues and Positivity sub-scales when compared to both restricted and no access. However, they did show a decrease on the Maintenance sub-score when compared to the other two groups and no change on the Fearfulness sub-score 

There were individual differences as can always be expected. For example, there were cases where the containment showed a negative effect on welfare scores, however these cases were rare. For us, important further research would therefore be to identify what factors could predict such a result and what factors could prevent/alleviate it, for example, making changes to the environment within the contained area.

Why do you think there was a change in Maintenance score? Could it be related to the hunting aspect of this sub-scale, for example, their hunting opportunity was decreased when in a barrier system? 

I do believe the hunting may have been played a big part on it. Another option could be that because of the possible reduced activity they needed less food and water (i.e. appetite and thirst), which could be interpreted either as a solution or a problem depending on the types of activity they were previously involved in pre-installation. For example, a reduction in appetite and thirst due to less activity spent in territorial disputes and fighting with other cats may actually be welfare enhancing as opposed to a reduction in thirst and appetite due to less general physical activity. It would definitely be worthy to investigate this further and try to understand the underlying reasons of each change for each group and individual

What would be your top tips from the results of your study and who would they be for?

For cat owners I would say that the most important point is related to having a practical alternative for ‘unsupervised access to outdoors’ and ‘living strictly indoors’ that keep a high quality of life for companion cats and also protects the wildlife. In this study, even cats that used to have unsupervised access outside of their homes seemed to show signs of improved welfare with a controlled outdoor environment. Therefore, you now have a third option which can also protect the wildlife.

Cats differ from each other in terms of their personalities and even their needs. When considering changing their living spaces (either by decreasing for cats that were roaming freely or increasing it for cats that were never allowed outside), a cats individuality must be considered so that adaptations promote positive welfare rather than impacting negatively on the cat. We certainly need more research on this topic to understand what can be done for individual cats with differing needs and what would be the best management for each cat.

Where do you hope the results of this study take you next?

I hope that after these exciting results we will be able to investigate further the long-term impact of these systems and how we can individualise the contained area for each cat in order to make sure they are all happy and healthy. Hence, a follow-up study would be to look at the welfare scores of these same cats after 6 and 12 months to see whether these benefits are sustained and in which way. It would be particularly important to understand the needs of those cats that did not show an improvement in welfare and adapt each environment according to their needs. These further studies would allow us to ensure a high welfare standard of all cats that live in this type of controlled environment.

Finally, a question we like to ask everyone we interview for Spotlight on Science, what’s your favourite thing about iCatCare?

I really admire the work that iCatCare does in order to improve cats’ welfare around the world, especially all the effort to increase people’s understanding of cats which is always based on research. For both medical and behavioural areas, studying and gathering evidence of the cause, symptoms and treatment are essential. Of course, professional experience is important, but it cannot be the only information we have to make decisions that will affect other living beings. That is why iCatCare has been revolutionising the field and having great impact on how cats are better treated.


A huge thank you to Luciana and the team for sharing their research. I certainly would be really interested to also see the research widened out to include cats and containment systems in other countries where risks associated with being outdoors differ, eg, in some countries there is more of a risk from predators. You can find out a little bit more about those involved in the study below.

Luciana: I’m originally from Brazil where I did my vet degree, residence, and masters. In 2014, I came to the University of Lincoln, UK to research canine behaviour and welfare. As you can see my research has also branched into cats! I love animals in general, especially dogs and cats and my aim in life is to help them to have better lives by improving their relationships with their caregivers, including my furry kids Nina Maria and Shiloh (my beloved cat and dog ?).

Daniel: I am a vet who has been working with problem animal behaviour for about 35 years now. I still see cases at the University of Lincoln, and lecture extensively on our MSc in Clinical Animal Behaviour; I also head up a large research group there, with research students working on cats, dogs and horses. I am particularly interested in what makes an individual unique and how this arises from their interaction with the environment. This links both my applied and fundamental research, for example by examining how we and non-human animals recognise and respond to the emotional state of one another. More recently I have had opportunities to scientifically explore my interests in the potential value of our relationships with animals. My research in this area focuses on the benefits from pet keeping using a multidisciplinary approach, for example collaborations with biologists, health care professionals, psychologists, lawyers and economists.

Eve: I was a lecturer in Byzantine History but my life took a different turn when we lost Lola, our 2 year old rescue cat, in a road traffic collision outside our house. We developed a solution to keep her brother, Leo, safe from the dangers of free-roaming. I became passionate about preventing feline tragedies and keeping cats safe outside, while enabling cat owners to experience peace of mind.


At iCatCare, we respect the diversity of the species and understand the individual cat. We are delighted to see another tool in the toolbox of how we manage outdoor access for our cats that takes into consideration both cat welfare and owner concern as ultimately, the two are so interlinked. If you are considering what would be best for your cat (indoors, unrestricted access outdoors or a containment system) the following pages on our website may help.

Outdoor cats

Fencing in your garden

(If you are interested in installing a barrier system for your cat, then purchasing a Protectapet system via the link in the article above means Protectapet will donate 10% of the purchase price to iCatCare for our charitable work.)

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