Question: What do Serbian Hound and St. John's water dog have in common?

Context paragraphs:
Tweed Water Spaniel: The Tweed Water Spaniel, or Tweed Spaniel, is a breed of dog extinct since the 19th century.  It is best known for being involved in the early development of the modern Curly Coated Retriever and Golden Retriever breeds of dogs.  They were described as a generally brown athletic dogs from the area around Berwick-upon-Tweed near the River Tweed and close to the Scottish Borders.  A type of water dog, the breed was not well known outside the local area.  This breed may have been created by crossing local water dogs with imported St. John's water dog, another breed which is also now extinct.

St. John's water dog: The St. John's water dog, also known as the St. John’s dog or the lesser Newfoundland, was a landrace (a dog bred for a purpose, not pedigree or appearance) of domestic dog from Newfoundland.  Little is known of the types that went into its genetic makeup, although it was probably a random-bred mix of old English, Irish and Portuguese working dogs.  The number of St. John's water dogs started declining by the start of the 20th century.  By the early 1980s, the variety was extinct.

Serbian Tricolour Hound: The Serbian Tricolour Hound ("srpski trobojni gonič" or "trobojac") is a breed of dog of the hound type.  Formerly called the Yugoslavian Tricolour Hound, the name was changed for clarity after the breakup of SFR Yugoslavia in 1991.  The breed was first exhibited at shows in 1950.  At one time it was considered a variation of the Serbian Hound, but was recognised by the Fédération Cynologique Internationale as a separate breed in 1961.

Wetterhoun: The Wetterhoun (FCI No.221, translated into English as the Frisian Water Dog) is a breed of dog traditionally used as a hunting dog for hunting small mammals and waterfowl in the province of Fryslan in the Netherlands.  The name of the dog comes from the West Frisian "Wetterhûn" meaning "water dog."  Plural of Wetterhoun is Wetterhounen in Dutch.  The breed may also be called the "Otterhoun" (not to be confused with the Otterhound) or "Dutch Spaniel", although it is not a Spaniel-type dog.

U.S. Virgin Islands Dry Forest: A Dry Forest are defined as a community of trees of different species that coexist in the same environment.  These trees can grow nearby forming a canopy above.  Dry forests lack an abundance of moisture, yet, there is an adequate amount of moisture to sustain the growth of the forest.  Although dry forest tends to grow at an intermediate height compared to moist forest.  Dry forest receives 850-1100mm of precipitation per year.  High quantities of sea salt from the ocean decreases the height of the trees.  Dry forest also consisted of layers of canopies, specifically two canopy layers that commonly found at an elevation below 300 meters.  There is limited dead dry wood for termites to consume, this correlates with low density of termites in dry forests.  The characteristics and development of Virgin Islands Dry Forest are contributed by a unique wind pattern that is usually strong.  Dry Forest usually thrive in environments that have plenty sunshine, steep slopes, on soil that are challenged by thin rocky layers that poorly absorbs water.  Within the three islands in the United States Virgin Islands, St. John has maintained a higher percentage of dry forest cover competing with St. Thomas at 43.1%; St. Croix has limited dry forest cover (9.22%).  St. John and St. Thomas topography has significant steep hills and slopes compared to St. Croix.  St. John is the most protected of the three islands, and as such it has the largest extensive tropical dry forests in the U.S. Virgin Islands.  The island contains 650 native plants, 5,000 or more terrestrial insects, over 180 species of birds, of which 90% are native, and six native mammal bat species.  One of the most common trees in the “native dry forest garden” is the amarat.  They are acacias, (casha bush) but do not have thorns likes most other varieties.

St. John's Regional Medical Center (California): St. John's Regional Medical Center is a hospital located in Oxnard, California in the United States, and is operated by Dignity Health, along with its sister hospital, St. John's Pleasant Valley Hospital in Camarillo, California.  The hospital was founded in 1912.  St. John's Regional Medical Center and St. John's Pleasant Valley Hospital offer comprehensive medical services, including 24-hour emergency medical and surgical services and care, cancer and oncology care and support, cardiovascular care, community outreach and screenings, diagnostic imaging services, laboratory services, maternity and women's services, neonatal intensive care, palliative care, patient and family education, rehabilitation services, spine and orthopedic care, weight loss surgery, wound healing and oxygen therapy, and more.  Together, St. John's Regional Medical Center and St. John's Pleasant Valley Hospital represent the largest acute-care health organization in Ventura County.  St. John's hospitals serve all of Ventura County and beyond, including the cities of Camarillo, Moorpark, Oxnard, Port Hueneme, Ventura, and Somis.

St. John, Indiana: St. John is a town in Lake County, Indiana, United States.  The town of St. John has homes in St. John Township, Hanover Township, and Center Township.  St. John was founded in 1837.  The population was 14,850 at the 2010 census.  In 2009, St. John ranked 48th among CNN's top 100 places to live in the United States.  In 2014, St. John was ranked as the 4th safest place in Indiana by Movoto Real Estate.

Moscow Water Dog: The Moscow Water Dog, also known as the Moscow Diver, Moscow Retriever or Moskovsky Vodolaz, is a little-known dog breed derived from the Newfoundland, Caucasian Shepherd Dog and East European Shepherd.  It is now extinct, but was used in the development of the  Black Russian Terrier.  The Moscow Water Dog was produced only by the Red Star Kennels, the state operated organization chartered to provide working dogs for the armed services.

Spanish Water Dog: The Spanish Water Dog (perro de agua español ) breed dates back several hundred years and has its origins most likely in Turkey from where it was imported into Spain as a general purpose sheepdog and guard.  It is also used sometimes as a gundog, and is skilled at retrieval from water.  The SWD has strong genetic links to other ancient water breeds such as the Portuguese Water Dog, the French Barbet and the Irish Water Spaniel.

Serbian Hound: The Serbian Hound (Serbian: Српски гонич / "Srpski gonič" ), previously known as the Balkan Hound (Балкански гонич / "Balkanski gonič"), is a pack hunting dog breed used in Serbia.  It is red or tan with a black saddle, neck and cranium and red or tan face.  Its head is flat and sloping, its muzzle pointed, with drop ears of the usual scent hound type.  The Serbian Hound stands 17 to 21 inches (44–56 cm) in height and weighs about 44 pounds (20 kg).  It is smooth-coated and coarse-haired.  Described as pleasant natured and obedient, the breed is thought to descend from dogs left in the Balkan region by the Phoenicians in ancient times.

Supporting paragraphs: Serbian Hound St. John's water dog
Answer: dog