Safe remedies to relieve constipation in German Shepherds.

Puree pumpkin. Like what you get to make pies with.

Vet tech here  How do you know they’re constipated? It’s pretty rare for dogs to actually get constipated and most often times the owners just see them squatting and straining out in the yard but in reality they’re having diarrhea and urgency to go.
What diet do they eat currently? Any other symptoms?

Pumpkin for costipation maybe watermelon if he likes it try raw carrots etc make sure he drinks lots of water.

Moose meat

Probiotics and pumpkin  or a little more exercise
Walking around and more movement should help. It works for people too.

But I would bring him to a vet to make sure there is no blockage 

My Dog had AF – So used Lactulose –
The other way Pro kaolin – But- over the years loads of issues in couple my dogs – Good Luck
Excessive toilet – look up Giardia – protozoan
) used Panacur liquid few years bk 3 consecutive days X

I give my girl Native Pet Probiotic. It has been a lifesaver.

Cooked Chicken and rice.

Raw Minced beef helps if they are feed dry feed just a small amount mixed into the bowl.

We add a little sweet potato to our’s regular food.

Boil up some fresh veggies.

Pumpkin for my big guy. If I notice it longer or if it turns into diarrhea – boiled chicken and rice for a few days rather than kibble.

Pumpkin, chic w plain yogurt.

It may have a blockage from something he ate
Vet is the best option in my opinion.