Tosa

Pinschers & molossoids

Large

10–12 y

FCI group 2 · Pinscher and Schnauzer, Molossoid and Swiss Mountain Dogs · The breed standard (FCI 260)

Uncited — a general reference figure, not a published one · no measured cohort for this breed

The Tosa, also known as the Japanese Mastiff, is a dog breed of Japanese origin that is considered rare. It was originally bred in Tosa, Shikoku, as a fighting dog and the only dog legally allowed in Japanese dog fighting. Ownership is restricted in some countries as a dangerous breed.

Quiet

Patient

Brave

Summary from Wikipedia (CC BY-SA) · reference ranges from the Kintail breed dataset

Adult weight

Reference

Male

45–90 kg

Female

40–70 kg

100

Breed club figure (the American Kennel Club)

Weight for age

Stock data

Male

Female

Expected range

Expected range from the breed's own adult weight, kilograms. Growth reference: Hawthorne et al. 2004, WALTHAM (five giant-breed fits, n=35).

Heat cycles · females

Stock data

First heat

8–12 mo

typical

Interval

180 d

typical

Bleeding

~9 d

typical

Proestrus 9d

Estrus 9d

Diestrus 52d

Anestrus 110d

General figures for dogs, not for this breed — individual cycles vary widely.

Questions people ask

Adult males usually weigh 45–90 kg and females 40–70 kg. Most are close to their full size by around 13 months, though the last little bit of filling out takes longer. Growth reference: Hawthorne et al. 2004, WALTHAM (five giant-breed fits, n=35).

No Tosa cycle figures are published here yet, so this is general guidance rather than a breed number: most females have a first season somewhere between six and fifteen months, and cycles then settle to roughly every 180 days. Smaller breeds tend to start earlier and larger ones later.

10–12 y — the usual range. Uncited — a general reference figure, not a published one · no measured cohort for this breed. How the later years go comes down to weight, teeth, exercise and regular check-ups far more than to the breed.