What It Is
An open fontanelle is incomplete closure of the cranial bones at the skull midline, leaving a persistent soft spot over the brain and sometimes occurring with hydrocephalus or other congenital skull abnormalities.
Also Called: open fontanelle; persistent fontanelle; molera; soft spot
Breeds Affected: Papillon
The Idiot-Proof Explanation
The skull did not close all the way, so there is a soft spot where bone should be. Sometimes it is just a small defect. Sometimes it comes with hydrocephalus or a fragile little head that makes every furniture corner feel personally threatening.
What Causes It
Open fontanelles are congenital, meaning the skull bones fail to close normally during development. Small openings may close as a puppy matures, but persistent defects can remain.
The big concern is whether the open fontanelle is isolated or part of a larger problem such as hydrocephalus. That difference matters a lot for prognosis and management.
- The skull bones do not fully fuse over the top of the head.
- Toy and small breeds are more often discussed with this issue.
- Some puppies outgrow small openings; some do not.
- A domed skull, neurologic signs, or behavior changes raise concern for hydrocephalus.
A soft spot is not automatically a disaster, but it is not something owners should ignore like a weird puppy feature.
What This Means for Life With This Dog
Life with a dog that has a persistent open fontanelle means protecting the head from trauma. Rough play, falls, and blunt force to the skull are bigger concerns than they are in a dog with a fully closed skull.
If hydrocephalus is involved, the future can include seizures, abnormal behavior, poor coordination, vision issues, medication, referral imaging, or surgery discussions.
The owner’s job is to know whether this is a harmless leftover opening or part of a neurologic problem. Guessing from the couch is not a diagnostic plan.
Can It Be Fixed?
A small fontanelle may close with age, but a persistent open fontanelle is not usually “fixed” unless related disease requires treatment. Management depends on whether the dog has neurologic signs or hydrocephalus.
Symptoms Owners May Notice
Soft spot on the skull: A noticeable opening may be felt on top of the head. Do not poke it like a button. The dog is not a vending machine.
Domed head shape: A rounded or enlarged skull can raise concern for hydrocephalus, especially when paired with neurologic signs.
Seizures or behavior changes: Hydrocephalus or brain pressure problems may cause seizures, dullness, abnormal behavior, or poor learning.
Poor coordination or vision issues: Affected dogs may seem wobbly, disoriented, or visually abnormal if the brain is involved.
Treatment Options
Veterinary exam: Your vet can assess the skull opening, head shape, neurologic status, and whether hydrocephalus needs to be investigated.
Monitoring and injury prevention: Mild cases may only need careful handling, head protection, and monitoring as the puppy grows.
Neurologic workup and treatment: If hydrocephalus is suspected, advanced imaging, medication, and referral care may be recommended. Severe cases may involve surgical options.
Recovery and Aftercare
Aftercare depends on the underlying issue. Isolated cases need careful handling and monitoring. Hydrocephalus cases need medication follow-through, neurologic rechecks, and an owner who does not treat head trauma risk like a fun challenge.
What Happens If You Wait
Waiting is risky if neurologic signs are present.
If the dog is having seizures, vision changes, dullness, or coordination issues, delaying care can mean worsening brain pressure and harder-to-control signs.
Cost Reality Check
Costs depend on whether the fontanelle is an isolated finding or part of a neurologic condition like hydrocephalus.
| Care Level | What It May Include | Estimated Cost |
|---|---|---|
| Initial workup | Exam, skull assessment, and basic neurologic screening. | $75-$300 |
| Ongoing management | Monitoring visits, medication if needed, and protective management. | $200-$1,000+ per year |
| Severe case | Neurology referral, advanced imaging, hospitalization, or hydrocephalus surgery. | $2,000-$10,000+ |
Neurologic signs: A soft spot with a normal puppy is one cost lane. A soft spot with seizures is a very different ride.
Need for imaging: MRI or CT is where the bill stops being cute.
Medication response: Some neurologic cases can be managed medically, while others keep escalating.
Trauma risk: A head injury in a dog with an open fontanelle can turn a manageable finding into an emergency.
Budget Reality Check
| Budget Item | Estimated Cost |
|---|---|
| Veterinary exam | $75-$250 |
| Neurologic consultation | $200-$600+ |
| Advanced imaging | $1,500-$4,000+ |
| Medication and monitoring | $300-$1,500+ per year |
| Hydrocephalus surgery | $4,000-$10,000+ |
Lifetime Cost Reality
| Case Pattern | Possible Lifetime Cost |
|---|---|
| Isolated mild finding | $100-$800+ |
| Managed neurologic case | $1,000-$6,000+ |
| Severe hydrocephalus case | $5,000-$15,000+ |
Tell Me What I Should Really Expect
An open fontanelle is not always a crisis, but it is never a toy feature.
The owner needs to know whether the dog is neurologically normal and how fragile the skull defect is. Protect the head, watch for signs, and involve a vet if anything looks off.