Weight gain can be very gradual. Also, since there are now so many overweight pets, being obese or overweight is starting to be seen as normal. Sometimes, owners of healthy-weight dogs say the are asked whether their pet is alright, because they seem thin in comparison to other dogs in the area.
To assess whether their pet is a healthy shape, owners can use the same method as vets and vets nurses do. This method is called 'body condition scoring', and involves using your eyes and hands to look at and feel areas where fat can be scored. Dogs and cats, for example, should have a clearly defined waist that tucks in behind their ribs when looked at from above. From the side, their waist should follow a clear line upwards behind their ribs, and should not be level or sagging. Owners should be able to easily feel the ribs of dogs, cats and rabbits by running their hands gently over them.
To help owners body condition score their pets, PDSA provides helpful leaflets and posters with pictures which can be downloaded for free via www.pdsa.org.uk/petfitclub.