If left unchecked, guinea pigs can put on too much weight rather quickly especially if they given the wrong sort of diet. If you are thinking about adopting a guinea pig from a rescue centre, the chances are they are just about at the perfect weight for their size. It is up to you to make sure they stay around that weight because if your new pet gets ill, knowing the difference in their weight helps your vet recognise any health issues.
It is really important to keep a record of your guinea pig's weight because knowing if your pet has lost or gained weight can be extremely useful when diagnosing a health problem. Vets find it much easier too because having this information helps them calculate over how long the weight fluctuation has been going on and this in turn helps them with their diagnosis.
However, it is also important to 'feel' the condition of your piggy because guinea pigs have a tendency to slim down without having lost any weight. This is especially true when they get to their more senior years. So 'feeling' and then weighing your pet is important, it lets you know about the overall health of your piggy.
You should try to make weighing your piggy part of your weekly routine. This is especially true if you have adopted a young guinea because they are still growing. Pregnant sows need to be weighed regularly too. It is okay to weigh your pet less often but never leave it for more than two weeks because a lot can happen in that time. You might miss a dramatic or slight change later rather than sooner. It also defeats the object of keeping track of your pet's weight if you do not do it regularly.
If your pet is unwell and refusing to eat anything, then you need to weigh them every day. If your pet continues to lose weight on a daily basis then you might need to discuss the situation with your vet. They would certainly recommend you syringe-feed your guinea and normally recommend feeding some specially formulated guinea pig food.
Guinea pigs reach adult weight when they are between 9 to 12 months, after this their weight normally stabilises. However, a few months down the line guineas do put on quite a bit of weight which is perfectly normal and nothing to worry about. Some guineas are naturally larger than others who can be quite petite just like in humans and other species of animals.
With this said the rule of thumb for the accepted weight of a guinea is between 2lbs to 4lbs (900g – 1800g) but this is just a guideline as some guineas are perfectly healthy if they are outside of these weights. The thing to remember is that if your pet is eating well, is healthy and can run around freely, then you don't need to worry about their size.
Luckily not many piggies become so overweight they are obese. Guineas naturally have large double chins which are called dewlaps. However, piggies are busy little creatures, they like to move around and get plenty of exercise. If you notice your pet is lethargic and is a little heavier than usual when you weigh them or pick them up, then it's time to think about looking at their diet. You should also see about getting your pet some toys to play with so they get more exercise.
If your piggy has a lot of excess fat around their abdomens as well as around the tops of their legs, then it is time to do something about a weight problem, and you can do this by altering their intake of food a little. But is also important to make sure your pet is getting enough exercise. Just like humans, guineas need to be fed a good balanced diet and have daily exercise in order to lose weight correctly.
You should never put your guinea on a 'diet' but you can cut down on any dry food you give them. One way of doing this is to change over to high quality hay-based pellets – the plain variety and then increase their exercise routine. You can be quite inventive when it comes to encouraging your pet to exercise – try putting your pet's food around their exercise area so they have to move around to find their favourite food.
You need to give your pet lots of toys too, things like tunnels, blankets, balls and soft toys. Not only will the toys get your guinea moving around, but it will get them interested in their surroundings. The rule of thumb is that a guinea needs at least one hour of daily exercise to lose weight and stay healthy and fit. If your pet lives in a small cage, then you have to make sure they have a large exercise area, or even let them run around a secure shed or garage making sure they cannot escape. If you let them run around a garage it has to be one that no cars are kept in because exhaust fumes are deadly to guineas.
You may notice small fluctuations in your pet's weight especially if you weigh them in grams. Small differences of up to 20z (60g) are perfectly normal and nothing you need to fret about.
Below is a general guide to expected weight gain for guinea pigs:
However, weight gain in pregnant sow can vary quite dramatically depending on how old the female happens to be and the expected size of her litter. When a female is expecting, she is 'in pig' and her weight needs to be monitored throughout the whole time until her litter is born.
You can weigh your guinea pig on any normal kitchen scales as long as they are accurate. Scales with bowls are ideal as your pet can sit in them as long as they are big enough. Before weighing your pet, always make sure you 'feel' the condition of your guinea too then jot down their weight in a notebook.
Keeping an eye on your guinea pig's weight is important, it can help your vet diagnose a health problem if you can tell them how your piggies weight has changed over a period of time. If you notice excess fat or flap at the top of your pet's legs and around their abdomens, then it is time to cut down on their food intake just a little and make sure your guinea gets enough daily exercise. Any sudden change in weight could be an indication of either a dental problem or an incorrect diet and you need to sort this out as soon as you can so your piggy stays fit and healthy.