Dr. Frank McMillan, in Understanding and Caring for Rescued Puppy Mill Dogs, has conducted an extensive study of puppy mill dogs and puppies. He provides the following definition of a "puppy mill" (applicable to kitten mill as well):
The above definition is important to know as it highlights key points about these facilities:
1. Profit-centered breeding facility (exists to make money)
2. in which the number of dogs (not just huge; can vary in size)
3. has exceeded the owner's ability (lack of knowledge, skills or resources)
4. and/or willingness (may know what's needed, but does it anyways)
5. to meet the physical and emotional needs (not just physical needs, emotional too which includes mental and behavioral health)
6. of all of the animals (includes adult breeding animals and the litters)
7. to a degree that permits the animals to have a decent quality of life (these are sentient beings who deserve a decent existence)
• Source of income
These breeding facilities (defined as substandard, negligent or horrific) view dogs and cats as ‘products’ to be mass produced for profit. Breeding is defined as a business. The more puppies and kittens produced, the greater the sales. Therefore, for these type of facilities, quantity of dogs and cats is the goal.
As this is a primary source of income for these breeding facilities, they and their supporters consider this form of breeding to be “free enterprise” or “making a fair living.” Puppies and kittens are commodities to be sold to pet stores or other companies (via brokers) or directly to consumers from the Internet or through classified ads.
• Repeated breeding
To produce as many litters as possible, adult breeding dogs or cats are bred continuously. While reputable breeders will stop breeding their females at a young age, problematic breeders will continue to breed the females at an older age — at 6, 8 or even ten years or more. Some of these animals are in-bred, passing on genetic diseases.
When the breeding dog starts giving birth to dead litters, that is a sign that she is no longer of "production use." The breeding animal (including males) is then killed, sold at auction or retired (e.g., kept within the facility, sold at discounted prices or given to rescue groups).
If the older, breeding dogs/cats are given to rescue groups, these groups assume the cost of care for these elderly animals, many of whom have higher medical expenses.
• Corners are cut
To maximize sales and profits, corners are cut in operations, such as providing minimal veterinarian care, poor quality or limited food and water, poor shelters (i.e., no or improper ventilation, lighting, and temperature control from the heat and cold), overcrowding in cages/pens, and no or limited grooming resulting in skin sores, matted hair and other conditions.
Sanitation is often poor (i.e., excessive feces and urine) with little or no pest and parasite control; this increases the spread of bacteria and disease, resulting in the animals becoming physically sick. (Animals could have infectious or zoonotic diseases which could be passed on to humans and other animals, if the animal is sold.)
Even if sanitation standards are met, high volume breeding facilities ‘save money’ by hiring fewer employees, contributing to behavioral issues because the animals have limited or no positive human contact, exercise, socialization and enrichment for proper mental and emotional development.
• Sold to consumers
Consumers are often unaware of these breeding conditions or physical and psychological health issues, and buy based on how “cute” the animal looks.
The unique difference with the dog and cat breeding industry (as compared to other businesse) is the fact that the 'product' is life, not an inanimate object.
Additional links below.