I wanted to add that my Mochi was yelping for no apparent reason for a few seconds and then would stop. It started from when she was 10 wks old and usually it was when she was changing positions while she was sleeping.Like hopeful4now mentioned she would almost jump up from a sleeping position or sometimes just be walking a few steps screaming and the plop back down to sleep. So odd. Every time I would run over and examine her but everything was ok. The vet told me all her tests checked out so I brushed it off. It happened maybe 5-7 times but at the time I wasnt aware of the prevalence of SM in Cavs. Believe it or not all my research on the breed prior to getting her revealed MVD as the biggest threat. As she got older she stopped doing it until she was 1 1/2 and the vet told us she had SM I asked him about these symptoms I could see now in retrospect and if it was the SM and he said probably so. He said she probably got used to some level of pain being a constant and thats why the yelping stopped but now it was progressing and becoming unbearable. I hate to end on a sour note but I want people to be aware that it can happen in pups. The vet told me breeding practices have become so bad that the younger Cavs are being diagnosed ((( Thanks to a good doc and meds she is happy and frolicking now ( aside from some itchy problems) but for the most part she is her old playful self. Since your babe was playing in the garden it's very possible he just got a prickly in his paw or overexerted a bit too much, Cavs are very fragile by nature. Please do enjoy his puppyhood because good health and happiness is nothing that should be taken for granted and should be enjoyed every moment! Take him to the park, give him lots of X's and O's, and love him like crazy b/c the future is fickle and you dont want to regret anything This might have been a little more rambling than what you were asking for so sorry about that lol :/