@dennis If there are Oppossums and Raccoons in your area do NOT let the Dogs eat grass.These animals carry a parasite that is transfered via the feces. In Horses it is called EPM and it is basically Horse Multiple Sclerosis. My 25 year old Quarterhorse had to be put down due to that. I now manage all of my Mares differently.
If these animals are in your area and there is something going on with your Dogs walking such as walking crooked or losing the control of the hind legs then you can ask the Vet (Horse Vets have the most experience with this) for a test that is done in South Carolina only. I will have to go through my Vet Records from when I had to euthanize my Horse to tell you the name of the Company that does this.
EPM mimics Lymes Disease and you should always have your Dog tested for Lymes. Lymes causes Cancer and it is a horrible disese.
No grass eating if the wild animals are in your area. In NJ where I live we no longer have these animals because the State Department of the Environment kills them. They do this because we have the Headquarters of the United States Equestrian Team here and the Horses are very valuable. I Board my Horses with a friend in PA right across the State Line so that is how my Horse got the EPM. There is no point in moving my Mares back to NJ because they have all been exposed. Eventually it will kill them.
I too would want a healthy Pup and if I were not so crazy about the Breed I would go to the Shelter and get a Dog from there. My Horses are always Owner Surrenders so I do not buy them. I am telling you this because it sounds like the Dog you lost may have been exposed to this Parasite.
This is a relatively new developement in diseases in Canids. The Vets do not know it when they see it and the Small Animal Vets do not share information with Equine Vets. There is a crossover and the AVMA which is PRO Slaughter for Horses and their Cousins does not inform the Small Animal Vets about things like EPM. I think this will be changing because as more Dogs are exposed and it is not Lymes they will have to admit there is something else going on.
Enjoy your Pups Dennis but do not let them eat the grass!