TFA says that those countries represent 6% of dog imports.
Also,
> Hundreds of these dogs had fraudulent rabies certificates,
Isn't this most easily fixed by requiring a post-immigration rabies shot?
If it is a pet, an extra hundred to couple hundred dollars is not much compared to all the other costs of moving. Just vaccinations and neutering could be as much for a replacement.
http://www.naiaonline.org/uploads/WhitePapers/USDA_DogImport...
In outside the covid pandemic, I think you will find that there is significant international travel for breeding and show purposes. Additionally, while I am unsure of the cost in the US, in a place like Australia the quarantine costs to bring pets into the country make it something more likely to be done by wealthier migrants.