I have both. It can get difficult for about 2 weeks every 6 months. If you plan to breed, you can find wonderful info on here and in cyberspace; then decide if it is the right thing to do or not. If you decide not to breed, then spaying and neutering will diminish any future problems. I use doggie diapers (like human infant pampers) while they are in heat. Yorkies should not be left to tie on their own. There are stages to the heat cycle. The female knows the right time and will give signals in advance. I'm only lightly touching on the subject but am adamant about researching before jumping in. Males tend to mark more in the house once bred. Thank God for belly bands
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