The phrase "excessive accumulation" means gathering or gathering too much of something. It refers to an amount that is more than what is normal or necessary. Full definition
This is especially applicable to overweight cats as excessive accumulation of fat in the liver can cause liver failure. (petsmagazine.com.sg)
To prevent excessive accumulation of cat hair in your house, there are a few grooming techniques that you can use. (vetinfo.com)
Note: By successfully completing an authorized traffic school program, you may be able to avoid excessive accumulation of negative points on your record. (dmv.com)