Ethics: Every year over 300 million turkeys are killed for Thanksgiving. This is after they have endured a torturous life in outrageously cruel conditions in factory farms. They are kept in tiny cages crammed with other birds, they're shot full of antibiotics (which the consumer later ingests), they're beaks and toes are cut off, and on it goes until they are loaded on a conveyor belt, their throats are slit and then they are dipped into boiling water to remove their feathers often while they are still alive. Not very appetizing.
Health: Turkey meat is not healthy! It's high in saturated fat and cholesterol which is implicated in various diseases such as heart disease, cancer, stroke, and diabetes. During processing, fecal matter routinely spills into the cavities of the birds via eviscerating equipment which leads to Salmonella and Campylobacter.
Environment: There are over 7000 turkey farms in the US. Much of the billions of pounds of manure generated by these factory farms ends up in our water supply. Grain consumed by turkeys could go to the millions of people starving in the world. As stated by the UN, factory farming is responsible for more co2 emissions than all forms of transport combined. So globally, it's not a wise use of resources.
And as a final note, I think vegan and vegetarian food is more delicious and would choose it regardless of any other reason. It's not a sacrifice, and additionally, it's often cheaper and faster, and it's more nutritious. For more information, check out PETA's guide to Vegan Holidays, there are tabs detailing the points above as well, if you would like more information on that. Also, a quick google search will yield hundreds of free vegetarian and vegan recipes appropriate for Thanksgiving.
