It doesn't have to take more than five minutes to examine your dog, says Hanna Lindén, a veterinarian at Arken Zoo. Regular checks help you spot anything unusual.
You start at the head and work your way back, feeling for lumps or skin changes, looking in the ears and learning what is normal for that particular animal.
Reluctant cats
Dogs often accept being petted and even see it as a cuddle. Cats can be more reluctant, and lumps may grow larger before they are discovered.
But a lump should be taken seriously: more than half of all dogs over the age of ten are diagnosed with cancer, and the most common form is skin tumors.
Female dogs can develop mammary tumors, and about half of them are malignant. In cats, they are rarer, but when they do occur, they are often malignant.
You can wait and monitor a small lump just a few millimeters across, but otherwise it is advisable to contact a veterinarian. It is difficult, even for a veterinarian, to assess a lump just by looking and feeling. The most common method is to take a needle sample.
Needle sampling is usually not difficult for the animal. However, some nodules may be too small to sample, and some do not release enough cells to make a diagnosis, says Hanna Lindén.
Not harmless
Just because your animal doesn't seem bothered by the lump doesn't mean it's harmless, says Henrik Rönnberg, a professor at the Swedish University of Agricultural Sciences (SLU) who researches tumor diseases in companion animals.
The thing about tumors in the skin is that they are often a local problem and do not have any general impact until perhaps quite late.
The longer you wait, the greater the risk that the animal will need major surgery, which may be more difficult to recover from, and that the veterinary bill will be higher.
Many pet owners wait too long, says Henrik Rönnberg, who wishes more people would seek care earlier for the sake of their animals.
Many dogs that come to me are those where you have thought for a little too long that it is a fatty lump, and when you can diagnose it, it is a disease that may have spread throughout the body or become so large and extensive that it becomes much more difficult to treat.
Skin tumors are the most common tumors in dogs. They can be benign or malignant, and are often noticeable as lumps or changes in the skin.
Mammary tumors are the most common tumors in female dogs. Studies show that about one in four to one in three bitches develops a mammary tumor during their lifetime.
They are especially common in older, unspayed bitches, but some breeds are also more affected.
In cats, mammary tumors are less common than in dogs, but when they do occur, they are more often malignant. The risk also increases significantly if the cat has been given birth control pills. About 80 to 90 percent of all mammary tumors in older, unspayed female cats that have been given birth control pills are malignant.
According to a survey by the insurance company Agria, 31 percent of cat owners and 47 percent of dog owners checked their pets at least once a month.
Source: Agria, Sveland