Preheat oven to 375 degrees F.
In a large bowl, add bread pieces and milk and allow to soak for 5 minutes.
While the breadcrumbs are soaking, roughly chop onions, celery, and peel garlic. Add to bowl of your food processor and pulse until very fine.
To the food processor with the vegetables, add bread mixture and pulse a few more times to combine.
To a large bowl, add ground venison, vegetable/bread mixture, 2 eggs, worcestershire sauce, tomato paste, italian seasoning and salt. Work the mixture together with your hands until everything has just come together but don't over mix.
Line a loaf pan with parchment paper. Pour in meat mixture and gently press to form into a loaf shape with a smooth top. Place into the preheated oven for 45 minutes.
While it's baking, create your glaze by whisking together apple cider vinegar, brown sugar, and ketchup.
Remove meatloaf from oven and carefully spoon on glaze before placing back in the oven for 15-20 minutes. The internal temperature should reach 165 degrees F.
Wait 5 minutes before slicing.