According to VetInfo, dogs get cramps and spasms for the same reasons humans do, especially when it comes to overexercise. When muscles are overused, they respond differently to movement which can sometimes lead to a painful muscular cramp. While leg cramps are most common for dogs, VetInfo acknowledges that cramps can occur in any part of the body.
VetInfo explains that cramps and spasms in dogs that are not due to overexercise tend to be caused by neurological experiences. The website notes that dogs can experience leg cramps that occur without any provocation or notice due to underlying neurological issues, such as seizures and degenerative myelopathy. Neurotoxins are another potential cause of muscle cramps and spasms, so VetInfo recommends that owners seek veterinary guidance to rule out a more serious cause before treating their dog's cramps and spasms at home.
Water Cures says symptoms of cramps in dogs include limping, slowed walking, avoidance of running or playing and pain in a limb when touched, which is often indicated by a vocalization. The website advocates keeping a close eye on a dog's fluid indicate and electrolyte balance. Balancing out a dog's electrolytes and making sure that the dog consumes adequate fluids for its age and activity level treats the cramps and spasms effectively and helps prevent them.