TL;DR: A soft spot on your dog’s head, known as an open fontanelle, is often a normal trait in toy breeds and typically only requires immediate veterinary attention if it bulges or is accompanied by neurological symptoms.
What causes a soft spot on the top of my dog's head?
The soft spot you feel on the top of your dog's skull is medically known as an open fontanelle, or a molera. Similar to human babies, puppies are born with skull plates that haven't yet fused. In many small or 'toy' breeds like Chihuahuas, Pomeranians, and Shih Tzus, these plates may never fully close, leaving a small, soft gap at the top of the head.
When is a soft spot on my dog's head considered an emergency?
While the urgency level for a soft spot is typically low if your dog is behaving normally, you should seek veterinary care immediately if you notice:
- The area appears to be bulging or swollen
- Seizures or tremors
- Coordination issues or loss of balance
- Extreme lethargy or neurological distress
How does sending a photo help a veterinarian triage my dog's soft spot?
Providing a clear photo of the top of your dog's head helps a veterinary professional provide an accurate triage recommendation by:
- Assessing the size and position of the molera
- Identifying swelling, skin discoloration, or unusual pulsations
- Determining if the skull structure is within a normal range for your dog's breed
Clinical Context (Merck Veterinary Manual)
Patent fontanelles, or "soft spots," are often present in dogs with hydrocephalus, which can indicate cerebral dysfunction. Clinical signs of hydrocephalus usually progress, though some animals may remain asymptomatic. Affected animals may also exhibit ventrolateral strabismus. Diagnosis can be achieved via ultrasonography through the fontanelle, CT, or MRI. Treatment relies on omeprazole to reduce cerebrospinal fluid (CSF) production or, if necessary, corticosteroids or surgery to shunt CSF into the peritoneum.
Chapter: Neurology, Surgery
Source: The Merck Veterinary Manual, 11th Edition (Page 1226)