Hello, I am Dr. Zoe. I am a licensed veterinarian here to help. Based on your brief description I am most suspicious Dundee may be having the early signs of Scottie cramp. Are you familiar with this condition?

If this is Scottie cramp, typically signs will appear after exercise and not when resting/sleeping. Puppies as early as 6 weeks or as late as 18 months of age can show signs of this problem. The severity of symptoms in affected dogs varies widely, as does the need for medication. Often times signs appear after a stressful event or during exercise. Signs can last from 1-30 minutes and multiple episodes can occur within a 24 hour period. She he is having the front leg shake, do you notice any "winging": the forelegs move out to the side and forward rather than straight forward. Sometimes, more severely affected dogs fall over.

This is the most likely cause, but there are certainly other possiblities such as referred pain from his neck or limbs, myasthenia gravis (very rare at this early age, although possible), a primary muscle problem (can be caused by a parasite such as toxoplasmosis or neospora), and the list continues.