Well, there is one way to cure it...First off you have to kill it. After this you need to get it's soul the Death God, Santa. He is the ruler of the Undead Dogs. He lives in the center of the Earth, in the core. The only entrance? The North Pole, that's right, the legions tell the truth. There is a secret outhouse there in which you have to eat all the crap inside. After you have eaten all of this you will be full and be able to journey down there and claim your dog's soul. Because he will be brought back to life, he will be completely healthy. But unfortunately the secret entrance only opens up once every march 3 on leap years. Once you have eaten all the poop, press 9 your cell phone and the Kuthulu will destroy the top hemisphere of the world, you then have to hurry and go into his mouth before the earth is destroyed and is consumed by the sun in 30 seconds. You will then be teleported to another demention. This place is called Elmo's Releam. You must slaughted Elmo in his labyrinth and steal his crown, then place the crown on your head and then use strength on the truck. This will activate a portal to the center of the earth, but make sure you brought some scizzor's pained blue and pink because other wise you will have to do this all over again by burning off your face and pouring acid on it until you die. So after you go through the portal you will be assaulted by 10,000 legions of skeletons with RPGs and shovels. Let them torture by shoving shovels up your butt and pulling them out your ear, again and again each time getting worse for 10,002 years and 34,004,146 months 9,395,044,103 * 10^9billion days then there is a .002% chance that the dark lord pizza will let you talk to bob for 2 seconds to convince him to let you use his elevator to go up 1 level. Santa is on the 2 billionth level. Keep doing this until you can get to the 2 billionth level. Once you get there you must kill Santa by ripping out his lungs and eating them. After that he will let you hump him. Hump him until he lets you see the dog souls. Once you see the dog souls you must look through every dog which has ever existed and find your dog, there are no names and your eyes will not work, if you touch the dog you will automatically pick that dog to set free. So start guessing if you guess wrong you will be humping Santa for all eternity while he licks your ear and tells you he loves you. And the level the dogs are on is not flat it is on a huge stair case which on either side is a pit that never ends. Once you pick the right dog it will be set free. But since you can only send one person back to earth its the dog. So your dog is sent to earth. Which is currently in the sun so he melts and is teleported back here. So it was all for nothing and you still have to be Santa's slave.
Been there done that.