Why do my dog's anal glands leak constantly, smell awful, and stain?
These are two little glands inside the dog's rectum. They naturally fill with a material that ranges from thin, light colored liquid to a thick paste. When a dog defecated, this material is released -- most of the time not all of the liquid is release but over the course of each defecation, enough is released that the glands do not overfill. With some dogs though, this process does not occur as easily. This can be due to the material being too thick to be expressed, the stool being too soft or diarrhea which does not apply enough force to the gland to express the fluids or due to an underlying disease process. The most common cause of recurrently full anal glands is an underlying allergy problem. Dogs with skin sensitivity or allergies often have anal glands that need to be emptied on a routine basis. If the glands become too full, the material can become infected or the gland can rupture. In this case, the area will heal but antibiotics are typically needed. After the anal glands are expressed, the area can continue to feel irritating for a few days. In some cases though, the glands may not have been completely emptied. This is often the case if the glands are emptied at a groomers as they empty them from the outside and are not trained to empty them rectally as a vet would. Most dogs do not need their glands emptied for any medical purpose but if the glands were randomly checked, they could be moderately full. This does not indicate a need to express the material though. The reason I bring this up is because I have found that if we begin emptying the glands for the dog, it creates a cyclic effect where we continue to have to empty them. If the dog is scooting, this is an indication to have them checked.
Updated on March 19th, 2026