Legal Question in Consumer Law in Michigan

It depends if the heartworm medication is approved for "use" either outside Australia and/or particularly in the U.S. There are definitely kinds of meds that are sold in the U.S. that are available to you, but if you want this particular kind, you should read the fine print on the seller's website. If it's not "approved" for use in the U.S., then that means you're not supposed to have it or use in the U.S. If you are ordering from a company, they will have a record of all sales and if anyone ever investigates, they will see that a US person ordered it. It's kind of like how people were buying cigarettes online through a company to avoid paying sales tax - the company made it sound like it was legal, etc., but then when the government investigated and cracked down, they went after every single person who had purchased cigarettes and not paid the state sales tax, trying to collect the taxes.

If the Australian's company's website doesn't provide you with any guidance, you may wish to explore the federal and state's websites regarding food and agriculture - such as the michigan department of agriculture.

The fact that it's an over the counter (OTC) and not prescription also makes a difference, and makes it less likely that it's illegal. But, on the other hand, it's just like any other product - certain furs, materials, plants, animals, etc. that are not allowed in the US for a multitude of reasons.

Remember, there are several prescription medications that are available or approved in Europe, but then aren't approved for use in the US, which would make it illegal to bring them into the US and/or use them here. Buying or bringing something into the US presumes that you will be using it.

If you can't find your answer, err on the side of caution and just don't buy it. Remember, that each country has different regulations and testing for all kinds of medications and there may be a very good reason that it's not available in the U.S.