Put a Lagotto Romagnolo and a Portuguese Water Dog side by side in photographs and you might struggle to tell which is which: two curly, woolly, water-loving breeds in the same brown-and-white family.

Put them side by side in your living room and the difference is immediate. These are not two versions of the same dog. They are two distinct working breeds, shaped by different jobs on different coasts of Europe, and the contrast that matters most, size, energy, and temperament, is the one the photographs hide. (We also compare the Lagotto with the Spanish Water Dog, its corded-coat cousin.) A family choosing between them is really choosing between two quite different daily lives.

This is the side-by-side: where the two breeds genuinely differ, where they are alike, and which one suits which kind of home.

Two Water Dogs, Two Different Jobs

Both breeds earned their living in the water, which is why they look related. The curly, near-waterproof coat is a working adaptation both share. But the jobs underneath were different, and the dogs were shaped to match. The Portuguese Water Dog worked the Atlantic coast of Portugal alongside fishermen: herding fish toward nets, retrieving gear and lost tackle from the sea, carrying messages between boats. It is, at heart, an athletic, exuberant, tireless water-working partner, a dog bred to swim hard all day and stay glued to its handler.

The Lagotto Romagnolo started as a water retriever in the marshes of Italy’s Romagna, but its modern identity is something no other breed holds: it is the only purebred dog recognized specifically as a truffle dog. When the marshes were drained, the breed was reinvented around the nose rather than the water, and a degree of independent, scent-driven focus was bred in. The result is a dog whose defining trait is not athletic exuberance but a working nose and a more measured temperament. Two water dogs; one became a swimmer, the other became a scent specialist.

Lagotto vs Portuguese Water Dog vs Spanish Water Dog
The three curly water dogs, side by side
Lagotto Romagnolo Portuguese Water Dog Spanish Water Dog
Size 16–19 in · 24–35 lb. Small-to-medium; compact enough to lift, travel with, and keep in a modest home. 17–23 in · 35–60 lb. A solid medium; a male at the top of the range is nearly twice a Lagotto. 15.75–19.75 in · 31–49 lb. A medium dog, broadly Lagotto-sized and well short of a large male Portuguese Water Dog.
Lifespan 15–17 years per the breed club, unusually long-lived for its size. ~12–14 years, typical for a robust medium breed, a few years shorter. ~12–14 years, similar to the Portuguese Water Dog.
Original job Marsh water retriever, reinvented as the world’s only recognized truffle-hunting breed. Fisherman’s working partner, herding fish toward nets, retrieving gear, swimming hard all day. All-purpose Iberian farm dog, herding sheep and goats, guarding the homestead, and helping fishermen with the nets.
Coat Curly, wool-like, low-shedding; regular professional grooming to prevent matting. Curly or wavy, low-shedding; a broadly comparable grooming commitment. Single woolly coat that naturally forms cords; never brushed, clipped down instead. Low-shedding.
Energy Moderate and substantially mental. A Lagotto is tired out as much by its nose as by running. High and physical, an athlete that wants sustained movement, ideally in water. High, a tireless herding-and-water worker that needs a real daily outlet.
With strangers Naturally reserved until introduced; devoted to its own family. Outgoing and exuberantly social; greets the world as a friend. Reserved and watchful, with a natural guarding streak from its farm-and-flock heritage.
Training style Very bright, but an independent thinker; rewards engaged, reward-based work. Very bright and biddable; the classic eager-to-please, handler-focused worker. Very bright and hardworking, but sensitive; early socialization tempers its wariness.
Best-fit home Wants a calm presence indoors and a job for the nose. A very active household with the time, and ideally the water, to match. An active household that can channel a herding dog’s drive and watchfulness.

The Size Difference Is Real

This is the first thing a family notices, and it is bigger than the photos suggest. The Lagotto is a small-to-medium dog. The Portuguese Water Dog is a solid medium, and a male at the top of the range is a substantially larger animal.

Size & Lifespan, Side by Side
Lagotto Romagnolo
24–35 lb
16–19 in · lives 15–17 yrs
A compact dog you can comfortably lift, that suits smaller homes and travels easily. Long-lived for its size. The breed club gives 15 to 17 years. Full size & lifespan figures.
Portuguese Water Dog
35–60 lb
17–23 in · lives ~12–14 yrs
A noticeably larger, more powerful dog. Males can weigh nearly double a Lagotto. Robust and athletic, with a typical lifespan a few years shorter than the Lagotto’s.

For a family weighing the practical realities, the size of the home, the car, how much dog you want at the end of the leash, and how many years you hope to have together. This is not a small distinction. The Lagotto is the more compact, longer-lived of the two; the Portuguese Water Dog is the bigger, more physically imposing dog.

Energy and Temperament: the Decisive Split

If size is what families notice first, energy and temperament are what they live with every day, and this is where the two breeds diverge most. The difference is not that one is good and one is difficult; it is that they ask for different households.

The Portuguese Water Dog is exuberant. Outgoing, high-energy, enthusiastically social, eager to please, the classic handler-focused working dog that wants to do things with you, ideally involving water and movement, for as much of the day as you can manage. It greets the world, including strangers, as a friend. For an active family that wants a robust, sociable, up-for-anything companion and can meet the considerable exercise demand, it is a wonderful dog. Under-exercised, that same energy turns to trouble.

The Lagotto is more measured. Affectionate and deeply bonded to its family, but calmer in the home and naturally reserved with strangers rather than exuberantly social, a watchdog-and-truffle-dog heritage showing through. Its energy is real but more moderate than the Portuguese Water Dog’s, and a good deal of it is mental: a Lagotto is tired out as much by using its nose as by running. For a family that wants an active dog that is also a calm presence indoors, and that finds the idea of scent work appealing, the Lagotto fits in a way the busier Portuguese Water Dog may not. We cover the breed’s character in full, including the real caveats, in our temperament essay.

Put simply: the Portuguese Water Dog brings more exuberance and more drive to swim and go; the Lagotto brings a quieter house and a working nose. Match the dog to the household you actually have.

Spanish Water Dog vs Portuguese Water Dog

Families comparing curly water breeds often add a third to the shortlist: the Spanish Water Dog, an all-purpose farm dog from the Iberian peninsula that herded, guarded, and worked the nets. Set the Spanish and Portuguese Water Dogs side by side and the split is one of size and temperament. On size, the Spanish Water Dog is the smaller of the two, a medium dog of roughly 15.75 to 19.75 inches and 31 to 49 pounds, closer to a Lagotto than to a big male Portuguese Water Dog, which can reach 60 pounds. On temperament, the Portuguese Water Dog is the exuberant, greet-everyone extrovert; the Spanish Water Dog is more reserved and watchful, with a herding-and-guarding streak that makes early socialization important.

The coats differ too. The Portuguese Water Dog carries a curly or wavy coat kept in a trim, while the Spanish Water Dog wears a single woolly coat that is left to form natural cords and is clipped down rather than brushed. Both are high-energy working breeds that need a real daily job. Where does the Lagotto sit in this three-way size comparison? It is the smallest and longest-lived of the three, and the only one bred to hunt truffles rather than to herd or swim. For the full picture of the corded cousin, see our Lagotto vs Spanish Water Dog comparison.

Where the Two Are Genuinely Alike

For all those differences, several things really are similar, and it is worth being clear about them so the comparison stays fair. Coat and shedding: both are low-shedding, curly or woolly breeds often called hypoallergenic, and both need regular professional grooming to prevent matting. Neither is a wash-and-go dog, and the grooming commitment is broadly comparable. (No breed is truly non-allergenic; our hypoallergenic essay explains why, and why meeting a dog is the only real test.) Intelligence and trainability: both are very bright and very trainable, and both do badly with harsh methods, though the Portuguese Water Dog is often the more biddable and the Lagotto the more independent thinker. Love of water: both adore it. Exercise needs: both are real working breeds that need daily activity and will invent their own if bored.

So the lazy version of this comparison, that they are nearly the same dog, is half right. On the coat and the brains and the water, yes. On the size, the energy, the sociability, and the lifespan, not at all.

A Lagotto Romagnolo digging happily in the sand at a Pacific Northwest beach
Both breeds love the water’s edge, one of ours, mid-excavation on a Washington beach.

The photographs show two similar dogs. Daily life shows two different ones.

Which Breed Fits Your Home

Choose aLagotto Romagnolo if…

  • You want a smaller, more compact dog, one you can lift, travel with, and keep comfortably in a modest home.
  • You want a calmer presence indoors: affectionate with family, without needing to greet the entire world with its whole body.
  • You are drawn to the nose, scent work and a genuine working specialty appeal to you, and you are happy to give that nose a job.
  • You value a very long-lived companion.
  • You are comfortable with a dog that thinks for itself, and rewards patient, engaged training over demands for blind obedience.

Choose aPortuguese Water Dog if…

  • You want a bigger, more robustly athletic dog and have the active lifestyle to match it, ideally one involving water, because few breeds love it more.
  • You want an exuberant, outgoing, enthusiastically social companion that greets strangers as friends and wants to be in motion with you for much of the day.
  • You can commit to substantial daily exercise, and will feel the difference if you fall short.
  • You prefer the eager-to-please, handler-focused working style.
  • The difference in typical lifespan is one you have weighed and accept.

For the right high-energy household, the Portuguese Water Dog is a magnificent dog. For the household that wants the quieter house and the working nose, the Lagotto is the answer, and the choice between them is really a choice between two daily lives.

The Honest Bottom Line

These two breeds get cross-shopped because they look alike, but the decision between them should rest on the things the photographs do not show. If you want a compact, long-lived, scent-driven dog that is calm indoors and reserved by nature, the Lagotto is your breed. If you want a larger, exuberant, water-mad athlete for an active family, the Portuguese Water Dog is. Both are intelligent, low-shedding, water-loving, and genuinely rewarding, in the right home.

If the Lagotto sounds like the better fit for your household, our full breed guide covers everything about living with one, and we are always glad to talk through whether the breed, and our dogs, suit your home. And if the Portuguese Water Dog sounds more like your dog, we would rather you choose the breed that fits your life. The goal is the right dog for your family, not simply a Lagotto.

Common Questions

What is the difference between a Lagotto Romagnolo and a Portuguese Water Dog?
They are both curly-coated water breeds, but underneath the coat they are quite different dogs. The Portuguese Water Dog is larger (around 35 to 60 pounds), higher in energy, and more outgoing and exuberant, bred for active water work alongside fishermen. The Lagotto Romagnolo is smaller (26 to 35 pounds), more moderate in energy, more reserved with strangers, and scent-driven, the only breed recognized specifically as a truffle dog. The Lagotto also tends to live notably longer.
Is a Lagotto Romagnolo smaller than a Portuguese Water Dog?
Yes, meaningfully. A Lagotto stands roughly 16 to 19 inches and weighs 26 to 35 pounds. A Portuguese Water Dog stands roughly 17 to 23 inches and weighs 35 to 60 pounds, with males at the top of that range being substantially bigger dogs. If size is a deciding factor, the Lagotto is the more compact, more apartment-and-lap-friendly of the two.
Which lives longer, a Lagotto or a Portuguese Water Dog?
The Lagotto Romagnolo, typically. The Lagotto Romagnolo Club of America gives a life expectancy of 15 to 17 years, long-lived for its size, while the Portuguese Water Dog generally lives around 12 to 14 years. Both are reasonably healthy breeds with their own genetic-testing protocols, but the Lagotto's longer expected lifespan is a real difference for a family choosing a long-term companion.
Is a Lagotto or Portuguese Water Dog better for families?
Both can be excellent family dogs; the better fit depends on the household. The Portuguese Water Dog's exuberant, outgoing, high-energy nature suits very active families who want a robust dog for water and outdoor activity. The Lagotto's calmer, more reserved, scent-driven temperament suits families wanting a somewhat lower-key companion who still needs a job for its nose. Neither is a low-effort breed. Both need exercise, training, and grooming.
Do Lagotto and Portuguese Water Dogs shed?
Both are low-shedding, curly or wool-coated breeds often described as hypoallergenic, and both require regular professional grooming to prevent matting. Grooming demands are broadly similar between the two. Neither is a wash-and-go breed. As with any dog, no breed is truly non-allergenic; individual reactions vary, and meeting a dog in person is the only reliable test.
Which is easier to train, a Lagotto or a Portuguese Water Dog?
Both are highly intelligent and trainable, with somewhat different working styles. The Portuguese Water Dog is often described as more biddable and eager-to-please, a classic handler-focused working dog. The Lagotto is intelligent and trainable but also more of an independent thinker, with a nose that can override commands; it responds best to engaged, reward-based training that channels its scent drive. Both do poorly with harsh methods.
What is the difference between a Spanish Water Dog and a Portuguese Water Dog?
Both are curly-coated working water dogs, but they come from different corners of Europe and differ in size, coat, and temperament. The Portuguese Water Dog is the larger of the two, roughly 17 to 23 inches and 35 to 60 pounds, exuberantly social, and bred as a fisherman's partner on the Atlantic coast. The Spanish Water Dog is a smaller medium, roughly 15.75 to 19.75 inches and 31 to 49 pounds, more reserved and watchful, and bred as an all-purpose Iberian farm dog that herded, guarded, and worked the water. Its woolly coat is left to cord and is clipped rather than brushed. Both are high-energy and need daily work.