Acorn squash is very low in oxalate, so it’s a fantastic addition to diets for dogs that tend to form calcium oxalate crystals and stones. This veggie has a 1:1 calcium to phosphorus ratio, provides healthy fiber to keep the GI tract robust and the microbiome more diverse. Bonus: dogs love it!
The shape and hardness of the raw squash makes it a pain to prepare if you do it the same way as most recipes for people instruct. While butternut squash can be found precut in the grocery aisle, or cubed and frozen, it’s not low in oxalate like the acorn variety. No worries! The following steps makes it much easier to include acorn squash in dog food recipes.
Rinse squash and pat dry.
Use a large, sharp knife to cut the squash vertically. Place the halves skin side up in a pan with about 1″ of water in it. 
Preheat oven to 400 F. Bake squash on middle rack for 45 minutes. Since ovens vary, check the squash sooner and time it accordingly. All you have to do is put a fork through the skin and into the squash. It should be over baked a bit for dogs. You want the fork to slide through the entire squash and touch the bottom of the pan easily.
Allow the pan to cool a bit. Turn the squash over and use a spoon to scoop out the seeds and a bit of the stringy fiber. Seeds can be rinsed a little and baked as snacks for yourself, or placed outside for birds and squirrels.
Scoop cooled squash and leave in fridge for up to 3 days, or place in containers for the freezer. Either way, it will leave some juice which you can include in the food you’re making for your dog.
Making large batches of squash makes sense when you can get a good deal on them, and for saving time and electricity. Deep roasting pans like these work well. The ones we use are 18″ x 12″ x 5″ high. They hold 3 large squashes (6 halves) and cook in a bit less time since the sides are high which causes heat and steam (from the 1″ of water) to surround the veggie more so than in a flatter roaster.