Rats and Mice

Rats are great pets, very interactive and affectionate, and easy to train. To help you care for them, this page has been co-written by Dr Claire and one of our best rat-owning clients.

Rats are becoming increasingly popular and we love to see them here at the clinic. Mice are also fabulous creatures and although the article focuses on rats, the advice can also be applied to mice. If you haven’t decided whether to get a rat or mouse, we would recommend a rat due their size, sociability, longer lifespan and minimal odour.

Both rats and mice can live in groups, though breeding will occur if not desexed. Rats often can live together in mixed sex groups, though it is best to introduce newcomers on neutral ground. Some rats will attack each other no matter what, and must be separated to prevent injury. Male mice cannot be housed together but females often get on well.

See also Feeding Rats and Mice and Desexing Prices.

Health & Disease

rat desexing anaesthetic
Rat anaesthesia via inhalaled gases, note pulse oximeter on foot

There is a good argument to purchase your rat from an established breeder instead of pet shops to avoid mycoplasmal respiratory disease. If you notice the rats sneezing, or breathing with some effort, beware. Once these pet shop cages are contaminated, it is very hard to prevent the next batch of rats to be housed in that cage from also being infected.

Dive deeper: Mycoplasma infection in rats

Pet rats are clean animals and do not carry any significant disease that can be passed to humans. Female rats & mice commonly develop mammary tumours late in life. These can be surgically removed quite successfully. If odour is a concern with mice, or your rats or mice are fighting, we recommend desexing the males. Desexing females may also help prevent mammary tumours. The picture shows an anaesthetised rat about to have desexing surgery at Walkerville Vet.

The third most common ailment is dermatitis, itchy skin and hair loss in rats. Follow the link to learn more.

A good idea is to weigh your rats or mice once a week and record the data. Changes in weight should set off alarm bells so you can get them to your rat vet in time.


rats sleeping hammock
Flickr Image via license

Good housing is the key to keeping your rat healthy. Think ventilation, ventilation, ventilation! Rats are prone to heat stress and also prone to respiratory infections. Both can be managed with adequate ventilation. Avoid housing rats in very small cages and in aquariums. Even aquariums cleaned daily can get toxic levels of ammonia (from urine) which damage their delicate respiratory systems and will cause chronic fatal lung conditions.

A bird cage/wire style rat cage with a detachable floor is the most recommended; unlike glassed in aquarium style cages, the wire cage can breathe and gain fresh air very easily and does not over heat or encourage condensation. These wire cages are typically easy to clean and allow the rats to have hanging objects to play and sleep in; keeping them active and alert is very much part of keeping a healthy rat.

The Lillas family: Our first rat was from a pet shop who kept them behind glass and she suffered from respiratory problems and was medicated her entire life. We never have wire floors on our cages either – never! It is very common for them to get a foot injury which fails to heal, in time becoming a chronic infected swelling called bumblefoot. If wire floors come with the cage, they are removed and replaced. We currently have two very good, mobile cages on wheels that have a big plastic floor with several series of holes which allow urine and faeces to drop through – these are expensive but really easy to clean, give the rats lots of area to run and play (they are three stories high) and they can also have some space to escape their roommates!

hooded rats
By Jason Snyder from Washington, DC, United States (WT and TK rat photo) [CC BY 2.0], via Wikimedia Commons

It is really important to ensure that they cannot escape from their cage (they can squeeze through very small spaces), that latches are tight and that there is plenty of room for them to run around, play and explore. It is really important to keep them away from draughty areas and away from direct sunlight and to keep them warm in Winter and very cool in Summer – they really do feel the heat. We place a large container of water in their cages for them to play in (shallow not deep) together with frozen peas on the really hot days.

Dr Claire: Rat cages should be placed in large well ventilated rooms. Family/lounge rooms are the best; avoid keeping them in small laundries or spare rooms that are not well used. The bedding should be mould and dust free. Paper based bedding is great. The paper cat litter called Breeders Choice is ideal. Use a generous amount of bedding covering the cage floor to absorb urine and protect delicate feet from bars along the bottom of the cage. To avoid ammonia buildup, replace the litter every day.

Rats love dens and hiding places. Cardboard boxes are great and can be easily thrown out when they get soiled. Rats enjoy toys and making dens. They love used toilet rolls, different types of paper and fabrics. They might use a wheel, or play with a small ball.

rat drinking

The Lillas Family: We generally use old tissue boxes, cut out the front and line them with old clothes, towels or sheets that have been cut up (these get changed every second or third day) The floor of our cages are covered in newspaper and this is changed every day as well. We purchase cheap, plastic hanging peg baskets from the supermarket and line these with bedding and hang them from top of their cages too – these provide very cheap (about $2) handy sleeping quarters and play equipment. We have purchased hammock style rat beds from the internet – they are terrific and warm but do get eaten up and chewed pretty quickly!

You can train your rat to use a litter tray but you will find that they will generally go one spot in their cage to do their ‘business’ anyway! They are very clean animals. As with all animals, they must have abundant fresh, clean drinking water which, for rats, is usually delivered via a drink bottle attached to the outside of the cage and they drink from a small spout.

The final point I would like to make clear – the first sign of illness ie sneezing, wheezing or signs of small lumps must be taken very seriously in rats. They must be given medical attention quickly. Once a rat is showing signs of illness, even grinding their teeth, they are usually very ill. Whilst they are the very best pets we have ever had, they break hearts with their oh so short life span so love them and enjoy them while you have them.