Louise, I find your husband's attitude toward your home country extremely chauvinistic and you have every right to be upset and to demand that he stop.
My husband is British and but we live here in the U.S. Generally, I have no problem with his criticisms; I, too, am critical of many aspects of life in the U.S. But recently he was seriously bashing my hometown, Detroit, where we live. To make a point, I said, "God, Newcastle [his hometown] is such a sh*&hole! Who would ever want to live there?!" I don't think he got how his criticisms were too personal until I said that, and then he apologized. Since then, he's actually praised Detroit a bit.
I'm tempted to say that all this will change if your dh moves to Venezuela; how could he possibly live with his preconceptions when he is actually living there? But having lived abroad for a number of years, I knew people who were really ignorant and critical of the country where I lived (Taiwan). So I guess what I'm saying is, it's important that you reach and understanding and let him know that in no uncertain terms may he say ignorant, offensive things about your home.
Your situation has reminded me of a David Sedaris book, "Me Talk Pretty One Day." It is a (hilarious) series of essays on his moving to France from the U.S. and his thoughts and experiences there. One thing that he said that I *so* related to from traveling abroad as a very young woman (19) was the realization that America (substitute Canada in your dh's case) is not number one, that other countries are patriotic, too, or as, David Sedaris writes (paraphrased), "other countries have mottos, too, none of which are, 'We are number 2.'" The book is riotously funny and maybe reading it would be a way for your husband to realize his ignorance and begin to be more open-minded...?