Monitoring Your Rabbit's Weight
Once your rabbit has reached adulthood, his or her weight should remain reasonably consistent. Any weight gain or loss may be an indication that your rabbit's diet needs adjusting or that there is an underlying health issue that needs to be investigated.
Is My Rabbit too Fat or too Thin?
It can be difficult to judge a rabbit's body condition visually because their thick fur can hide prominent bones or disguise fat. It will help you to feel your rabbit so you can tell what is underneath the fluff.
A rabbit that's a healthy weight should have a smooth curve from neck to tail, and from hip to hip. You should be able to feel the spine and ribs but they should feel rounded not sharp - like they have a thin layer of padding. It's normal, particularly for females, to have a roll of fur under the chin (called a dewlap), this can look like fat but should just feel like a fold of skin when gently pinched.
Note: These photos have been altered digitally; no bunny was harmed during their production.
As a rabbit looses weight the bones of the pelvis and the ridges of the spine and ribs become increasingly prominent and feel sharp and angular. A very underweight rabbit will have depressions each side of the pelvis and spine. As fat decreases muscle starts to be lost too, which means the legs will be thin and their ability to move maybe compromised.
As a rabbit gets overweight their ribs, hips and spine become hard to feel beneath the layer of fat. Rolls of fat often develop around the tail and ankles, and the dewlap (the fold of skin under the chin) can become extremely large and feels plump. Fat also develops on the chest and stomach area, and may hang down underneath. Viewed from above the rabbit has no obvious waist.
Weighing Your Rabbit
It is much easier to identify changes in your rabbit's body weight using scales rather than visual cues. Checking your rabbits weight regularly will act as an early warning sign of a problem that needs addressing. It's much easier to adjust your rabbits diet at the first sign of weight gain than once your rabbit is already noticeably fat.
You can weigh your rabbit on normal kitchen or bathroom scales. If your rabbit won't sit still, weigh your rabbit in a carrier, and then deduct the weight of the empty carrier. Make sure you keep a note of the date and weight so you can keep track of changes.
What should my rabbit weigh?
This is a difficult question because every rabbit is an individual. Weight varies between rabbits, even those of the same breed, so it is important you compare your rabbit to his normal weight not a breed average. For example, the BRC Breed Standards state that a Dwarf Lop should weigh between 1.93kg and 2.381kg. This is a difference of almost half a kilogram - which would take a rabbit that should be on the lower end significantly overweight and one on the higher range, underweight.
If you are unsure if your rabbit is the correct weight then your vet will be able to examine your rabbit and give you an idea of the ideal weight for your specific bunny. If your rabbit has already been to a vet they may already have a weight recorded for you rabbit recorded in their notes - phone and check.
If your rabbit puts on excess weight, it is a sign that his diet is providing too much energy and the excess is being stored as fat. Rabbits generally become over weight due to overfeeding energy rich foods, like commercial dry rabbit food, combined with a lack of exercise. A healthy adult rabbit that is gaining weight may need its diet altered to prevent it becoming over weight. This is usually done by reducing the amount of dry food, or feeding a brand that is higher in fibre, and topping up with more hay and fresh foods (leafy greens not high sugar fruits and root vegetables).
If your rabbit is losing weight then it could mean his diet is not providing enough energy and his body is using up stored energy to compensate. However, it is rare for rabbit's to lose weight purely through a lack of adequate nutrition. Often weigh loss signals a medical problem so you should always consult a vet before assuming it is a diet related.