Dogs disappearing after going through a portal

I had tamed wolves and I transported them back into the portal to my base. It was successful seeing them go through the Nether. Afterwards, we went through the second portal from the Nether to my base and Im the only one who went through. All of us entered the portal but they couldnt be find at the overworld. I tried going back to the nether and different portals we went through but they werent there. Its like they have been deleted or something.