It may just be that the soft limit switch is getting stuck in when it runs over the dog. If you spray some WD-40 onto the button of the limit switch and work it in and out may solve your problem. If a stuck switch is not the problem. You probably just need to open your Y axis positive stroke limit. They are usually set around 2000 - 6000. I'm not sure what the parameter # for this control would be, but you should be able to find it in your parameter or maintainence manual. Open that limit to 999999 and then home the machine with the overides turned down low. Once the machine has found that home position you can change the parameter back to the original setting.