Julie Wilson and her husband were diligently giving their dog Kooshka monthly medication to prevent heartworm infestation when, to their astonishment, Kooshka tested positive for heartworm during a routine exam.

Their veterinarian, Dr. April Wyatt, was astonished in turn to learn that the owners had been taking steps to protect their dog from the potentially deadly parasitic condition. Kooshka’s records did not show that she had ever been prescribed heartworm prevention drugs, although Wyatt recommended it a year earlier.

“When I asked where they had gotten it, she said her husband had gotten it online,” recounted Wyatt, who practices in North Carolina. At that moment, the veterinarian realized that “this poor owner and this poor pet got stuck in the middle of something shady.”

It turns out that Kooshka’s owners purchased an Australian product called Nuheart, a generic form of ivermectin modeled after the brand-name medication Heartgard. Nuheart is sold over the counter in Australia but the drug is not approved in the United States or Canada.

Moreover, all heartworm-prevention drugs in the United States and Canada require prescriptions. Yet many such products — approved and unapproved — are available online without a prescription from numerous outlets that operate in the shadows of international Internet commerce.

“We have been chasing this,” said Sharon Kerr, an inspector and practice consultant with the College of Pharmacists of British Columbia. She said the Royal Canadian Mounted Police have pursued dubious online vendors as well, but the authorities are stymied frequently.

“There’s so much Internet business going on involving other countries that we have no control over,” Kerr said. “Every time they start closing in on something, (the suspects) close their Internet address and they’re gone. It’s a worldwide (problem).”

Some online pet pharmacies flaunt their ability to sell heartworm medications without prescriptions. One website goes by the name http://heartwormmedicinewithoutprescription.com. The site www.heartworm-medicine.info recently elaborated on the situation this way:

“All of the cheap heartworm medication for dogs or cats that are purchased here are shipped from Canada. The Canadian heartworm medicine rules are slightly different to those in the U.S. and other countries in so far as the majority of the cheap heartworm meds that they have available are able to be sold prescription free. People have asked whether or not this is legal and can you buy heartworm medication from Canada and have it shipped to their address outside Canada.

“It seems this is one of those grey areas that are simply not clear cut. Whether it is lawful is still being debated, but this is for the prescription meds. While there is no answer to this question at the moment I suggest that you take the opportunity to buy heartworm meds without prescription while you can.

“...From what information there is it seems that it is not strictly legal to buy the heartworm meds that need a prescription in Canada and have them shipped to the U.S. or the U.K. But the rules have been loosened and no U.S. customs are going to seize any prescription meds and because most of the meds here are non prescription in Canada there is certainly nothing wrong with ordering them, even if they require a prescription in our own country.”

(The quoted passage appears to have been removed from the website as of last week. However, the site on June 25, 2009, as captured by the Internet archiving service Wayback Machine, contains similar language.)

Kerr said it is untrue that heartworm medications in Canada may be sold without a prescription; heartworm medications do require a prescription in her country. She also said that only medications approved in Canada may be sold by Canadian pharmacies.

Neither heartwormmedicinewithoutprescription.com nor heartworm-medicine.info identifies the individual(s) or company behind their website. The sites provide no contact information other than a form for submitting comments or queries online. Neither responded to repeated messages submitted by the VIN News Service.

The heartwormmedicinewithoutprescription.com site is registered to Domains By Proxy, Inc., of Scottsdale, Ariz., a firm that shields domain-name ownership information from public view. The heartworm-medicine.info site is registered to an unnamed entity with an address in Nassau, the Bahamas.

Among the approved heartworm prevention medications sold by the sites is Heartgard, the brand-name ivermectin product, which is made by Merial. Although Merial products, like those of most other pet pharmaceutical manufacturers, are readily available through a variety of retail outlets through diversion, the company has a policy of selling only to licensed veterinarians.

“Merial plays no part in the unauthorized and illegal sale of HeartGard through Internet merchants or elsewhere,” Dr. Zack Mills, Vice President of Pet Sales for Merial U.S, said by e-mail. “While we cannot be certain where Internet merchants source their supply of the product, it is likely from a country where heartworm preventives may be legally purchased without prescription.

“However,” Mills continued, “products from other countries are not required to be in compliance with FDA labeling regulations, so even with a prescription it would be unlawful to sell them in the U.S.”

The U.S. Food and and Drug Administration (FDA) seems well aware of the proliferation of Internet pet pharmacies. It has posted several “buyer beware" cautionary statements. One such posting states: “Websites that sell prescription veterinary medicines without valid veterinary prescriptions are breaking the law.”

Asked to elaborate on pharmacies located out of the country, Laura Alvey, a spokeswoman for the FDA’s Center for Veterinary Medicine, cited the Food, Drug and Cosmetic Act in her response by e-mail: “...a pharmacist who dispenses an Rx drug without a prescription has misbranded the drug and violated the FD&C Act. If you sell a drug that has to be Rx here to a consumer in the U.S. without a prescription, even if from overseas, there may well be a violation of the Act.”

However, she noted in a separate e-mail on the same issue: “FDA’s jurisdiction is within the U.S. and we don’t oversee or regulate the practice of pharmacy.”

Some Internet outlets appear adept at exploiting cross-border jurisdictional gaps. Case in point: Total Pet Supply, a pet pharmacy that emphasizes “the most affordable prices” and sells Nuheart to buyers in the United States.

Total Pet Supply lists a street address in Blaine, Wash., a small city on the border with Canada. Employees who briefly answered queries from the VIN News Service made to their toll-free customer-service number and by e-mail stated that the Blaine address is used for mail only and they are physically located in Surrey, B.C., which is a 15-minute drive from Blaine.

Repeated requests by the VIN News Service for more information went unanswered. The U.S. mailing address used by Total Pet Supply is that of a Mail Boxes Plus.

Mail Boxes Plus owner Christina Hannon said Total Pet Supply is part of a larger organization, Canada Pharmacy, that sells human and veterinary pharmaceuticals through numerous websites. She said it uses the Washington address to receive prescriptions from customers in the United States and that a courier from nearby White Rock, B.C., picks up the mail each week.

Hannon said she is paid rent on mailboxes each month via PayPal and does not know the name of the company’s principals. “I don’t want to know. It’s not my business,” she said.

A Google search of Total Pet Supply’s mailing address — 477 Peace Portal Dr. Suite #436, Blaine, Wash., and variations thereof — yields links to several other online pharmacies, including www.canadamedicineshop.com, www.birthcontrol.com, www.canadapharmacy.com, www.canpharm.com, www.canadageneric.com, www.petcarechoice.com and www.canadianpharmacytrust.com.

The sites are registered to Cook Orbit Domain Limited or Asiaciti Trust Pacific Limited, which share an address in the South Pacific Cook Islands. Asiaciti Trust Pacific’s website describes the firm as an international trustee and fiduciary services group based in Singapore with operations in Hong Kong, the Cook Islands, Samoa, New Zealand, Nevis and Uruguay. The company did not respond to e-mail messages and a telephone call from the VIN News Service inquiring about its relationship with the Internet pharmacies.

Total Pet Supply does appear to be aware of the VIN News Service’s inquiries, however. In a brief telephone conversation Thursday, Hannon at Mail Boxes Plus said she was unable to give further information about the company. “They called me and said not to,” she said.

In Blaine, Total Pet Supply is operating without a city or state business license under that name, according to City Clerk Sheri Sanchez. She noted that the city’s position on the border makes it a popular location for mailing addresses. “We get companies who want to use the city’s address to show a presence in the state of Washington, and so when they do that they need a business license,” Sanchez said. “...We do get a lot of people from Canada who set up a presence in Blaine. We can’t catch them all, especially if they don’t apply for a state license.”

Washington state records also show no license for a pharmacy going by the name Total Pet Supply, according to Susan Teil Boyer, executive director of the state Board of Pharmacy. Boyer said that if the company maintains a storefront acting as a pharmacy in the state, it must be licensed. Whether a mailing address equates to a storefront is unclear, she added.

As for the legality of non-FDA-approved products being shipped to customers in the state, “the laws are silent,” she said. “There’s nothing on the books (in Washington) that says you can’t receive a prescription as a patient from a Canadian pharmacy. It isn’t addressed.”

The VIN News Service placed an order for Nuheart to confirm that Total Pet Supply does not require a prescription for heartworm medication and is selling non-FDA-approved product. The Nuheart arrived with shipping labels showing return mailing addresses in Australia and New Zealand.

Foreign Internet pharmacies operate outside the rules with such apparent ease and confidence that their practices are interpreted by some observers as legitimate.

The popular how-to website eHow features an article titled "Non prescription canine heartworm medication." The article reads in part:

“In the United States, purchasing heartworm preventive requires a prescription, according to the AHS (American Heartworm Society), which owners use to buy medication from their veterinarian or through a U.S. pharmacy. The U.S. Food and Drug Administration requires a licensed vet to prescribe heartworm preventive because giving the medication to a dog already infected can lead to severe or fatal consequences. However, when dogs test negative for heartworm some U.S. owners turn to the less expensive option of ordering heartworm preventive from Canada. These non-U.S. orders do not require a prescription.”

The article goes on to give this advice for ordering heartworm medications:

“Once a dog is declared heartworm-free by a veterinarian, he or she will recommend the best preventive and dosage for your dog. If an owner chooses not to purchase preventive from the vet and pursue an online purchase without a prescription, several Canadian pharmacies can provide the medication, generally at favorable prices. Many Canadian pharmacies that carry medication for humans also carry heartworm preventive for dogs. A Google search for Canadian pharmacies is the best place to begin comparison shopping online.”

Contacted by the VIN News Service, eHow spokeswoman Nicole Rodrigues said she would ask the site’s editorial team to review the article and consider revising it. “We are open to people saying, ‘Hey, by the way, this is wrong’ or ‘This is outdated,’ ” Rodrigues said. “We’re trying to provide the best information possible out there and we’re constantly updating and fixing our content.”

Julie Wilson, the dog owner who bought the Australian product Nuheart on eBay, said she and her husband did not make the purchase thoughtlessly. “We did a lot of research online. Honestly, I probably should have called the vet, but I didn’t,” she acknowledged. “ ... We found several articles from different people saying (Nuheart) was the same medication and would work just as well as the Heartgard would. So I felt comfortable.”

Wilson said she was shocked when her veterinarian informed her that heartworm medication requires a prescription. “I would not have thought I would have been able to get it if that were the case,” she said. “There were no questions asked whatsoever.”

Now that she knows, Wilson unfortunately is unable to identify the party from whom she purchased the product. “Apparently after a while, eBay deletes the record details,” she said. “I can see the sale but none of the information on the seller.”

Heartworm disease can result in serious injury to the lungs and heart. Even the treatment can be risky. Fortunately, Wilson's dog Kooshka appears to be none the worse for the experience. At the time she was diagnosed with heartworm, Kooshka was showing no clinical signs of illness, Wilson said, suggesting that the infestation, which is caused by the bite of an infected mosquito, was not severe. Her veterinarian recommended a treatment regimen, and Kooshka is responding well, her owner said.

As for Wilson, she’s now buying the brand-name medicine Heartgard directly from her veterinarian and not worrying about the higher cost. “You get what you pay for,” Wilson said. “Learned that lesson!”