My dog freaks out when we leave him alone?

My dog had parvo not to long ago and whenever we leave him alone now he freaks out when we come back. We also had another dog but he died from parvo and my puppy that survived parvo freaks out. We asked our vet why he freaks out an the vet said if dogs have near death experiences they do that. But I think it's because our other dog died. He doesn't really freak out but he gets overly excited.

Separation anxiety

Get him another dog as a playmate so he's not alone. But get its shots and dont let it get parvo.

wow !! i was reading your question and thinking did my husband write this ? this is the exact same thing what is going on with our 9 mth old male chihuahua.mid july our 1 1/2 yr old chihuahua died at the vet of parvo,he was then taken to our vet right away,he to was infected with parvo,when he was there she had passed away,he was there 4 day's on a iv and medication.he came home and had to be on meds for a week,but we have a older female chihuahua who is alway's home with him if we leave our home.he does the same thing to us what your dog is doing to you,when he hear's us pull up he's so happy whining,barking very excited, jumping on the couch to look out side,or if one of us goes out side to check the mail,he act's like he has not seen us in a long time,also if were going out of town ( my dog's also go ) my husband will be pumping gas our male dog start's crying and looking for him.my vet also told us the same thing,because our other dog had died there and we almost lost him,i also think it's because your other dog died as well as mine did and your dog is acting like my dog is.i think both of our dog's had parvo almost died and lost their buddy's that's why the dog's are acting like this.hope my story help's you..