一般我们会说" 我的狗在咬我的作业,我不是在开玩笑." 一般,当动物在 eat something (like: homework, blanket,cushion... )时， 我们会用"咬",不用"吃"

我们家的狗在咬我的作业本，我没有在跟你开玩笑。

Hello Alex , You rather say then : 我的狗在吃我的功课。 The literal translation would be then as you said: " My dog is eating my homework....." But it doesn't make sense in English too, what do you mean exactly?

Alex is not kidding, his homework was just a cake.

The sentence is right, but it needs two exclamation points " !" !"