Foods to Avoid

​As a general rule of thumb if a food is safe for humans to eat in that form then it is likely to be safe for rats.  However there are some key foods that should be avoided;
  • Dried / Uncooked Beans (unless on above list) – this particularly includes Kidney Beans and Soya beans (can be fed fresh e.g. .  Beans contain high levels of antinutrients when dried and these can interfere with the digestion of other foods.  Some beans such as kidney beans can be quite toxic when dried.
  • Liquorice root – may cause neurological issues if a lot is consumed, a small amount of liquorice in a tea or sweet is unlikely to cause this affect unless lots is fed.
  • Very spicy chilli’s (the type that hurt to touch or get in your eyes) – mildly spice chilies may be appreciated by some rats and are safe to feed in moderation, as are the dried chilli’s that can be found in some parrot feeds. Bear in mind though that rats will not have developed a tolerance to chilli so will not usually appreciate spicy chilli’s especially with seeds.
  • Citrus for boys – note: if a boy accidentally ingests a small amount of citrus this is unlikely to cause issues.  Instead issues are caused by the build-up of D-limonene in the body, which is mainly found in the pith and skin of citrus fruits (but can be found in small amounts in lots of other fruit and veg).  If citrus fruits are fed regularly this is where you see the issue
  • Mouldy soft cheese – the moulds found in these are often toxic to rats and can cause issues. 

Foods which may cause issues to some rats

  • Claggy foods like peanut butter, dry mashed potato etc. – these can cause choking as they stick in a rats throat, mix with a bit of water to loosen before you feed it.  
  • Foods containing Lactose - not all rats are lactose intolerant contrary to some myths, however much like humans there are those that are.  If you want to introduce cows milk or related products do slow gradually and stop if the rat has diarrhoea.

Foods to limit

As with humans there are a lot of foods out there which are not good for them and so should only be fed very rarely, or better still not at all.  However some less healthy foods can be useful to disguise medication in or bulk up a skinny rat so they can be worth bearing in mind.  Just remember when treating a rat that a small treat of unhealthy food is a lot bigger to them than us, and a rat who isn’t fed unhealthy food will not know that its missing out and get just as excited by a healthy treat as an unhealthy one.
  • High fat foods – the key thing here is to remember that not all fats are equal, foods high in saturated fat should generally be avoided, yet foods high in omega 3 are often very useful, and some fats like coconut and other nut oils can be useful improving coat and skin condition.  Generally avoid any high fat foods that are seen as unhealthy for humans (e.g. chips, crisps, cheese etc.)
  • High sugar foods – rats should not have a lot of sugar, whilst in the wild they are often attracted to it as an easy source of calories in pet rats who live a lot longer a diet high in sugar can cause issues.  Part of this is causing facial and tooth abscesses, the rats mouth shape with flaps to protect the back part of the mouth making it both impossible to clean there back teeth and also potentially trapping sugary foods around the molars.  Sugars are also far too easy source of calories, meaning rats tend to get fat more easily on them.  Some sugars are less of an issue than others.  Fruit sugars, particularly those in berries, are generally better than more refined sugars, though these should be principally fed as raw fruit.  Be sensible though and aim to feed no more than once or twice a week or as a small part of a veg mix.
  • High salt foods – as with humans a lot of salt is not good for long term health, and can dehydrate rats too.  They are particularly problematic in rats with heart issues and should be avoided all together then.  Generally there is no good reason to feed high salt foods to a rat so it is worth avoiding.

Common Food Myths

There are a number of food myths out there spread via the internet which are based on issues in other animals (particularly dogs and cats) which are wrongfully believed to be dangerous to rats.
  • Chocolate – elements in chocolate can cause issues in dogs and cats at sufficient levels.  This is not the case for rats, who tolerate it much better much like humans.  This food is still high in sugar and fat so shouldn’t be given regularly, however in some circumstances it can be useful as it is a bronchial dilator.  If using it in this way then aim for the very dark chocolate and give only a tiny piece at a time.
  • Raisins – much like chocolate this stems from the belief raisins shouldn’t be fed to dogs.  Raisins and other dried fruit are actually fine in moderation to rats.  They are still high in sugar so should only be fed in small amounts however they can be useful as part of a balanced diet as some in particular currents contain reasonably high levels of copper. 
  • Garlic and onion – in some countries it is believed that garlic and onion (being a member of the same family as daffodils etc. which have poisonous bulbs are also toxic to rats, especially when raw.  Whilst in high amounts this is true (and also true for humans!)  the levels that a rat is likely to eat by choice are perfectly safe.  Aim for no more than one garlic clove per rat and a teaspoon of chopped raw onion, more can be fed of cooked variants.  Both offer good health benefits particularly in the raw state.
  • Dried rice – this myth appears to link to the myth that dried rice fed to seabirds causes them to explode.  There is about as much truth in both.  It is based on the belief that the rice is so dry it absorbs the moisture in the stomach and expands causing bloat in a rat.  In reality the way the rats grind up the rice means this is not going to happen, added to the fact that you are unlikely to feed a rat a diet of entirely dried rice (and nor should you) this is not a risk.  In fact rice is one of the most useful grains for rats, it is low phosphorus and easy to get hold of, forming a staple part of the original brown rats diet.  This combined with Barley represent the most kidney kind grains for rats.