Gestation periods, shortest to longest
| Animal | Gestation | Range or in days | Source |
|---|---|---|---|
| Rabbit | 31 days | 28 to 35 days | GestationPeriod calculators |
| Dog | 63 days | 58 to 68 days from breeding | AKC |
| Cat | 63 to 67 days | About 9 weeks | Petfinder |
| Sheep | 147 days | 142 to 152 days | Merck Veterinary Manual |
| Goat | 150 days | 145 to 155 days | GestationPeriod calculators |
| Cow | 283 days | 279 to 292 days by breed | GestationPeriod calculators |
| Horse | 340 days | 320 to 370 days | GestationPeriod calculators |
| Llama | About 11 months | About 335 days | IFAW |
| Manatee | About 13 months | About 396 days | IFAW |
| Tapir | 13 to 14 months | 396 days to 426 days | IFAW |
| Donkey | About 14 months | About 426 days | IFAW |
| Camel | 12 to 14 months | 365 days to 426 days | IFAW |
| Giraffe | About 15 months | About 457 days | IFAW |
| Walrus | 15 to 16 months | 457 days to 487 days | IFAW |
| Rhinoceros | 15 to 18 months | 457 days to 548 days | IFAW |
| Sperm whale | 14 to 16 months | 426 days to 487 days | IFAW |
| Orca (killer whale) | About 17 months | About 517 days | IFAW |
| Asian elephant | 18 to 22 months | 548 days to 670 days | IFAW |
| African elephant | 22 months | About 670 days | IFAW, BBC Science Focus |
Gestation is counted from conception or mating, and the figures are averages. Individual animals vary, and the range depends on the species, the breed and the animal.
How the figures compare
- A cow's 283 days is about nine months. A mare carries for about 340 days, nearly 11 months.
- The African elephant, at 22 months, has the longest gestation of any land mammal. Science Focus gives the same figure.
- Whales are not far behind: sperm whale 14 to 16 months and orca about 17.
- Smaller animals are quick: a rabbit is 31 days and a dog 63 days.
Farm and pet animals, with calculators
For elephants, see the elephant gestation page, which has the due date for any conception date. Animals that are pregnant should be checked by a vet, because the averages above cannot tell you whether one individual is healthy.
Frequently asked questions
Which animal has the longest gestation period?
Among land mammals, the African elephant at 22 months. The frilled shark may go up to three and a half years.
How long is a whale pregnant?
A sperm whale is pregnant for 14 to 16 months and an orca for about 17 months.
How long is a giraffe pregnant?
About 15 months.
Sources
- IFAW: Animals with long gestations
- BBC Science Focus: Which animal has the longest pregnancy?
- American Kennel Club: How long are dogs pregnant?
- Petfinder: How long are cats pregnant?
- Merck Veterinary Manual: Breeding, parturition and common lamb diseases of sheep