TL;DR: An open fontanel is a common soft spot on the skull of toy breed dogs that is typically not an emergency but requires careful monitoring and protection from head injury.
What is an open fontanel in dogs?
An open fontanel, also known as a 'molera,' is a small gap or soft spot on the top of a dog's skull where the cranial bones have not fully fused. This condition is most common in toy breeds, particularly Chihuahuas, and is often present from birth. While it sounds frightening, it is a known characteristic in several small breeds.
Is an open fontanel a medical emergency for my dog?
- The urgency level for an open fontanel is Low if your dog is behaving normally and meeting developmental milestones.
- It is not an emergency if there are no signs of neurological distress.
- Because the brain is less protected in this area, you must be extra cautious about potential head trauma.
- Mention the condition to your veterinarian during your next routine appointment for proper monitoring.
Why should I provide a photo of my dog's open fontanel for triage?
- Sharing a photo or video helps veterinary professionals assess the size and location of the opening.
- Visuals allow experts to check for bulging, pulsing, or skin irritation over the site.
- This helps determine if the fontanel is a benign physical trait or a symptom of an underlying condition like hydrocephalus.
Clinical Context (Merck Veterinary Manual)
Patent fontanelles (open molera) are often present in animals with hydrocephalus, and affected animals may also exhibit ventrolateral strabismus. Diagnosis can be confirmed through ultrasonography (via the fontanelle), CT, or MRI. Treatment options include omeprazole to reduce CSF production, corticosteroids, or surgical CSF shunting into the peritoneum.
Chapter: Neurology, Surgery
Source: The Merck Veterinary Manual, 11th Edition (Page 1226)