Dog & Cat Pregnancy Due Date Calculator (Whelping / Queening)
Expected whelping or queening dates from the LH surge / progesterone rise, first breeding or first day of diestrus.
Results are calculated in your browser. Always double-check before administering and use your clinical judgement.
How it is calculated
Dogs: parturition 64–66 days from the LH surge / initial rise in progesterone, 58–72 days from the first day the female permitted breeding, and 56–58 days from the first day of diestrus [1].
Cats: parturition 64–66 days from the LH surge triggered by copulation [1].
Worked example
LH surge 1 Jan 2026 → due 6–8 Mar 2026.
Frequently asked questions
How long is a dog pregnant?
Parturition occurs 64–66 days from the LH surge or initial progesterone rise, or 58–72 days from the first breeding [1].
How long is a cat pregnant?
Parturition in the queen occurs 64–66 days from the LH surge triggered by copulation [1].
More calculators
References
For veterinary professionals. Information supports — never replaces — clinical judgement; always check the current product label and local regulations.