Animal rescue organizations and animal shelters have replaced pet stores as the primary source of dogs throughout the United States.

Unfathomably, concerns about the health of dogs imported from other states and countries are rarely discussed. Unsuspecting adopters could end up with dogs that have serious, sometimes fatal diseases.

For example, dogs that have been increasingly imported from Puerto Rico may be infested with heartworms and suffering from heartworm disease, which according to the AVMA is "a progressive, life-threatening disease."

There are reportedly 100,000 stray dogs in Puerto Rico, where abandoning dogs is common and spaying and neutering is not the common practice.

According to "The Sato Project," a nonprofit organization formed to rescue abandoned & abused dogs from Puerto Rico, heartworm infestation is widespread in Puerto Rico.

Roughly 70% of the dogs The Sato Project rescues are heartworm positive, requiring expensive and lengthy medical treatment.

The AVMA confirms that heartworm is prevalent in dogs in Puerto Rico:

There is a distinct geographic pattern for heartworm disease, with the highest prevalence of heartworm infection in 2015 occurring in the Southeastern states and Puerto Rico.

The American Heartworm Society whose "Mission is to lead the Veterinary Profession & the Public in the understanding of Heartworm disease,," explains that heartworm disease "is caused by foot-long worms (heartworms) that live in the heart, lungs and associated blood vessels of affected pets, causing severe lung disease, heart failure and damage to other organs in the body."

Signs of heartworm disease may include a mild persistent cough, reluctance to exercise, fatigue after moderate activity, decreased appetite, and weight loss. As heartworm disease progresses, pets may develop heart failure and the appearance of a swollen belly due to excess fluid in the abdomen. Dogs with large numbers of heartworms can develop a sudden blockages of blood flow within the heart leading to a life-threatening form of cardiovascular collapse. This is called caval syndrome, and is marked by a sudden onset of labored breathing, pale gums, and dark bloody or coffee-colored urine. Without prompt surgical removal of the heartworm blockage, few dogs survive.

Heartworm is not the only disease of concern in dogs imported from Puerto Rico for adoption. Rabies cases in dogs from Puerto Rico have been diagnosed, as reported by the CDC:

During 2014, domestic animals accounted for 47.9% of all animals submitted for testing, but only 7.37% (n = 445) of all rabies cases reported, representing a decrease of 4.71% compared with the 467 reported in 2013.

Of the fifty-nine rabid dogs reported in 2014 . . . [m]ost of the rabid dogs were reported from Texas (n = 14 [23.7%]), Puerto Rico (12 [20.3%]), and Oklahoma (9 [15.2]).

While clearly there are abandoned, stray dogs in Puerto Rico in need of homes, these animals may harbor diseases that will decrease their longevity or require significant veterinary care and related expenses, that unwitting adopters may not be aware of.

Moving the unwanted stray dogs from Puerto Rico to adopters on the mainland will not stop the continued overpopulation on that island without more.

Animal rescue organizations like The Sato Project and Second Chance Animal Rescue importantly do not just remove dogs from Puerto Rico and offer them for adoption, they also educate local residents about the importance of responsible pet ownership, which includes preventing unplanned dog breeding by proper sterilization of owned dogs. That still may not be enough to change the landscape on the island.

.At the same time, responsibly and purposely-bred dogs should not be banned to force pet owners to obtain dogs only from rescue sources.

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