Why does my Jack Russell Terrier shake so frequently?

Jack Russell Terriers are known to shake frequently due to their high energy levels and natural instincts. This shaking behavior can be a way for them to release excess energy, excitement, or anxiety. It is also common for small breeds like Jack Russells to shake when they are cold or feeling stressed. Regular exercise, mental stimulation, and a comfortable environment can help reduce shaking behavior in Jack Russell Terriers.