| Country of origin: | Spain |
| Registries: | Pyrenean Mastiff Club of America |
| Occupation: | Livestock guardian |
| Size: | 55–75kg (121–165lb), 71–80cm (28–31in) |
| Longevity: | 8 to 10 years |
| Exercise: | Moderate |
| Training: | Patient training needed |
| Grooming: | Moderate |
| Colors: | White with black and fawn |
The Pyrenean Mastiff, also called the Mastin d’Aragon, shows obvious crossing between white mastiffs and lighter-coloured Spanish mastiffs. When working as flock guards, these dogs still wear the traditional carlanca – a spiked collar that protects the neck from attack by wolves. Selective breeding has made this a reliable companion for experienced dog owners.