Umbilical Hernias in Chihuahua Puppies: Size, Closing, and When to Repair

By Rev. T. Stringer, Lead Researcher, SIPGS

An umbilical hernia is a soft bump at the belly button.

It is one of the most common things new owners find on a Chihuahua puppy.

Most are small and harmless.

Many close on their own.

A few need a simple repair.

What it is

Before birth, the umbilical cord passes through a small ring in the belly wall.

After birth, that ring is supposed to close.

If it does not close all the way, a small gap stays open.

A little fat, or the belly lining, can push through the gap.

That makes the soft bump.

How to tell what you have

Feel the bump gently with a fingertip.

What you feel · What it usually means

• Soft, painless, pushes back in: A simple reducible hernia
• Small, about the size of a pea: Often only fat. Often closes on its own
• Firm, will not push back in: Fat stuck in the gap. Have your vet check it
• Hard, hot, red, or painful: Emergency. Tissue may be trapped

Size matters

The size of the gap is the most important number.

Under 1 cm (about ¼ inch)

Small hernias like this may close on their own by:

3 to 4 months of age

Over 1 cm, or still open at 5 to 6 months

These are unlikely to close without surgery.

When it needs repair

Surgery is recommended if:

• the hernia is still open at spay or neuter time
• the gap is large
• the bump is firm, growing, or will not push back in

The repair is simple.

The vet closes the gap with sutures.

It can be done at the same time as the spay or neuter, under the same anesthesia.

Few puppies have a recurrence after repair.

Emergency signs

Go to a vet right away if the hernia:

• turns hard, hot, red, or dark
• becomes painful to touch
• will not push back in when it used to

Or if the puppy:

• vomits
• stops eating
• has a swollen or painful belly

These can mean a piece of intestine is trapped and losing blood flow.

Is it genetic?

Yes, in many cases.

Umbilical hernias run in some family lines.

Can the dam cause it?

Yes.

A dam that pulls hard on the cord, or chews it off too close to the belly, can cause a hernia.

Experienced breeders see this often.

Some genetic advisors call this a myth.

Hands-on whelping experience says otherwise.

So there are two causes:

• a ring that does not close, which runs in families
• damage to the abdominal wall at birth, when the dam pulls on the cord

You can't always tell which one you have.

Watch the dam at whelping, and note which puppies she handled roughly.

For breeders:

• A dog with a small hernia can be bred, but not to a mate with a hernia, or a mate with close relatives who have one.
• Do not use a male with a hernia heavily.
• Dogs with large hernias that need repair should not be bred.
• Track hernias in every litter, by sire and dam.

Hernias in other places, like the groin, are a different problem.

They are not known to be inherited the same way.

Care at home

• Check the bump every day. It should stay soft and painless.
• Note the size. Measure it with a fingertip or a ruler each week.
• Keep the area clean.

Gentle rubbing

Many breeders, and our own vets, recommend gently pushing a small, soft hernia back in and rubbing around it a few times a day.

It is safe on a soft, painless hernia.

There are no published studies on whether it speeds closing.

Do not rub a hernia that is firm, red, or painful.

• Show it to your vet at every puppy visit.
• Plan the repair with your spay or neuter if it has not closed.

Key takeaways

• An umbilical hernia is a gap in the belly wall where the cord passed.
• Under 1 cm, many close by 3 to 4 months.
• Still open at 5 to 6 months, it will likely need surgery.
• The repair is simple and can be done with the spay or neuter.
• Hard, red, painful, or stuck means emergency.
• Umbilical hernias run in families. A dam pulling hard on the cord can also cause one.
• Breed small-hernia dogs carefully. Do not breed dogs with large ones.

Sources

• Weir M, Hunter T, Ward E. (2025). Umbilical Hernia in Dogs. VCA Animal Hospitals.
• ASHGI. Umbilical Hernia (handout).

© 2026 A & A's Chihuahuas and Rev. T. Stringer. All rights reserved.

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