Capacity for care, explained
Capacity for care is the number of animals a shelter can care for humanely at one time, given its housing, staff, money and available outcomes. Operating within it is linked to shorter stays, less disease and more live outcomes.1
The one formula to know
Average daily population = average daily admissions × average length of stay
The Association of Shelter Veterinarians' guidelines put it this way: two shelters with the same intake can have very different populations depending on how long animals stay.1 At 10 admissions a day, a 7-day average stay means about 70 animals in care; a 21-day average stay means about 210.
| Admissions per day | Average stay | Animals in care on an average day |
|---|---|---|
| 10 | 7 days | 70 |
| 10 | 14 days | 140 |
| 10 | 21 days | 210 |
Try it with your numbers in the free kennel capacity estimator.
Capacity is more than kennels
Housing is the visible part, but the ASV guidelines say capacity also depends on trained staff, resources and the outcomes actually available, including foster homes.1 Animals with medical or behavior needs take more care time per day.
The Capacity for Care (C4C) model
UC Davis Koret Shelter Medicine Program's C4C model sets a target daily population from historic intake and outcomes and a realistic target stay, then manages stays proactively so the shelter stays at or below that number.2 In a study of three shelters that adopted C4C for cats, average length of stay fell by 31%, 11% and 9%, the probability of adoption rose, and fewer cats needed isolation.3 A separate study at the Guelph Humane Society found cats' stays fell 24% after C4C began.4
How to work out your own numbers
- Admissions per day: last year's intakes ÷ 365, ideally by month, since intake is seasonal. Our shelter pages show typical seasonal patterns.
- Average stay: use the mean, not the median. Long stays add up.
- Multiply to get the average population, then add room for busy days. Real populations swing well above average in peak months.
- Compare with the number of animals you can house and care for well. If it's higher, you have two levers: fewer days per stay, or fewer or smoother admissions.
Where length of stay comes from
Every day in care is time waiting for something: a hold period, an exam, surgery, a behavior evaluation, photos, a listing, a transfer slot. Pathway planning and daily population rounds are how shelters find and remove those waits.1 See our guide on reducing length of stay.
Members can run the full kennel-flow simulator and 30/60/90-day capacity forecast on their own data.
Sources
- Association of Shelter Veterinarians, Guidelines for Standards of Care in Animal Shelters, 2nd ed. (2022), section 2 (Population Management).
- UC Davis Koret Shelter Medicine Program, Capacity for Care (C4C) resources.
- Karsten CL, Wagner DC, Kass PH, Hurley KF (2017). An observational study of the relationship between Capacity for Care as an animal shelter management model and cat health, adoption and death in three animal shelters. The Veterinary Journal 227:15-22.
- Janke N, Berke O, Flockhart T, Bateman S, Coe JB (2017). Risk factors affecting length of stay of cats in an animal shelter: a case study at the Guelph Humane Society, 2011-2016. Preventive Veterinary Medicine.