Early signs of possible CH occur very early on in a dog’s life. Signs can be seen from when they start moving around . Whilst still with their littermates it may be noticeable that the puppy falls behind their littermates development. They would have trouble sucking, swallowing and moving . One of Holly’s first signs of having difficulties was that she struggled to get to the food bowl – whilst her littermates were dashing to the food bowl, Holly was struggling to move across the floor to the bowl. Puppies that may have CH tend to not be able to hold a stand, and are less likely to be able to feed themselves due to falling and lack of balance. Toileting is also known to be difficult as the puppy finds it difficult to balance.
Important: If you do have a puppy that is showing these symptoms, it is vital that you contact a vet, don’t just presume it is CH from reading this. There are many other neurological conditions that can show similar symptoms of Cerebellar Hypoplasia that need different medical care. Always seek professional advice.
Symptoms of Cerebellar Hypoplasia in dogs can range in severity. A mild case of CH can be hardly noticeable whereas severe cases can cause tremors, and difficulty in walking, eating and everything really except for sleeping . Symptoms of Cerebellar Hypoplasia do not get worse, they stay the same. Dogs with the right support can adjust to their challenges and may learn behaviours that can help manage the difficulties they face. It’s also important to remember that dogs born with CH know no different and that CH in itself doesn’t cause the dog any pain.
The main symptoms of Cerebellar Hypoplasia are ATAXIA, DYSMETRIA and INTENTION TREMORS
Ataxia is the presence of abnormal, uncoordinated movements or, as the term means, a lack of order. Ataxia can be a symptom of different neurological disorders, if your dog shows signs of abnormal, uncoordinated movements it is essential that you seek the advice of a veterinarian professional as soon as possible.
Ataxia in dogs with CH will typically have an abnormal way of walking. They can be very unsteady on their paws once they find them. Dogs with Cerebellar Hypoplasia tend to walk with a high step; this is called hypermetria. Some dogs look like they are doing some sort of dressage. We call it dancing as she has a little bounce and a touch of swagger as she walks.
Dysmetria means that a dog would have difficulty regulating the distance, power and speed of movement, again this can be seen in other cerebellar disorders .
Intention Tremors are when a dog focuses and tries to do something like watch a moving object or eat from a bowl. Their head and neck will start to bob back and forth or will shake gently. Again, intention tremors can be a sign of a different neurological problem and should be checked with a vet at the earliest opportunity.
Nystagmus (flickering and twitching of the eye) 
Different-sized pupils in the eyes (rare)
References:  GreatPetCare