FetchBreedFind Your Breed

Mastiff vs Portuguese Water Dog

Side-by-side comparison for prospective owners weighing both breeds.

TraitMastiffPortuguese Water Dog
Weight120230 lbs3560 lbs
Lifespan610 yrs1113 yrs
Est. monthly cost$150–$280$100–$170
Energy level
Grooming needs
Shedding
Trainability
Good with kids
Good with other pets
Vocalization

Where Mastiff and Portuguese Water Dog differ most

  • Adult weight: Mastiff 120–230 lbs · Portuguese Water Dog 35–60 lbsMastiff much heavier
  • Energy level: Mastiff 2/5 · Portuguese Water Dog 5/5Portuguese Water Dog much higher-energy
  • Daily exercise: Mastiff ~40 min · Portuguese Water Dog ~75 minPortuguese Water Dog much needs more
  • Grooming needs: Mastiff 1/5 · Portuguese Water Dog 4/5Portuguese Water Dog much more upkeep
  • Lifespan: Mastiff 6–10 yrs · Portuguese Water Dog 11–13 yrsPortuguese Water Dog much longer-lived
  • Est. monthly cost: Mastiff $150–280 · Portuguese Water Dog $100–170Mastiff much costlier

Full trait-by-trait breakdown

TraitMastiffPortuguese Water DogVerdict
Adult weight120–230 lbs35–60 lbsMastiff much heavier
Energy level2/55/5Portuguese Water Dog much higher-energy
Daily exercise~40 min~75 minPortuguese Water Dog much needs more
Grooming needs1/54/5Portuguese Water Dog much more upkeep
Shedding3/51/5Mastiff sheds more
Trainability3/55/5Portuguese Water Dog easier to train
Good with kids4/54/5About the same
Good with other pets3/53/5About the same
Vocalization1/53/5Portuguese Water Dog more vocal
Lifespan6–10 yrs11–13 yrsPortuguese Water Dog much longer-lived
Est. monthly cost$150–280$100–170Mastiff much costlier
Hypoallergenic realityNoLower-shedding (not hypoallergenic)Differs — see profiles

Which one should you choose?

The gap here is about as wide as size categories allow. The Portuguese Water Dog is a medium-sized, high-drive athlete that genuinely needs vigorous daily exercise, historically bred to work alongside fishermen, while the Mastiff is a giant breed with famously low energy, content to rest for most of the day. Trainability strongly favors the Water Dog, one of the most responsive breeds around, compared with the Mastiff's independent, occasionally stubborn nature. Coat routines flip expectations: the curly Water Dog sheds almost nothing but still wants frequent brushing and the occasional clip, while the Mastiff's short coat gets by with an occasional brush and little else. Both tend to be gentle with kids, though the Mastiff's sheer bulk calls for more supervision around small children. Choose the Water Dog for an athletic, highly trainable, low-shedding companion; choose the Mastiff for the most sedentary, lowest-grooming giant-breed presence available.

Whichever breed fits your life, consider adoption or breed-specific rescue first — many purebred and mixed-breed dogs and cats are already waiting for homes.

General breed information, not veterinary advice — consult a vet for your pet's specific health, diet, and behavior needs.