Hoof Wall Separation Disease in Connemara Ponies

What buyers and breeders need to know

Hoof Wall Separation Disease (HWSD) is one of the most important inherited conditions in the Connemara pony. It affects the structure of the hoof and, in affected animals, can have serious implications for soundness and long-term welfare.

The condition is now well understood and, importantly, it can be fully managed through DNA testing and responsible breeding decisions. For anyone buying or breeding Connemaras, understanding HWSD is essential.

What is Hoof Wall Separation Disease in Connemaras?

HWSD is a genetic condition that affects the formation of the hoof wall. It is caused by a mutation that interferes with the normal production of keratin, the protein responsible for strength and integrity in the hoof.

In an affected pony, the hoof wall does not develop properly. Instead of forming a strong outer structure capable of supporting weight, it becomes weak and prone to splitting and separation.

What are the signs of HWSD in Connemara ponies?

Affected ponies typically show signs early in life, often within the first few months. Common signs include:

• Cracking and splitting of the hoof wall
• Separation between layers of the hoof
• Difficulty holding shoes due to poor nail quality
• Progressive weakening of the hoof structure

In more severe cases, the hoof wall may fail to support the pony correctly, leading to lameness and ongoing management difficulties. While some cases can be managed carefully, others can present significant welfare concerns.

What do N/N, N/HWSD and HWSD/HWSD mean?

HWSD is inherited as an autosomal recessive trait. There are three possible genetic results:

• N/N (Clear) – the pony does not carry the mutation
• N/HWSD (Carrier) – the pony carries one copy but is clinically normal
• HWSD/HWSD (Affected) – the pony has two copies and is very likely to develop the condition

A foal must inherit the mutation from both parents to be affected.

Can you breed from a HWSD carrier Connemara pony?

Yes — and in many cases, it is the correct decision.

A carrier pony is not affected and does not suffer from the disease. The key point is that breeding decisions must be made properly.

• Carrier × Carrier → 25% chance of affected foal (should be avoided)
• Carrier × Clear → 0% chance of affected foal (acceptable and widely used)
• Clear × Clear → all foals clear

Responsible breeding is not about removing every carrier. It is about avoiding the production of affected foals.

Why you should not automatically avoid carrier ponies

One of the biggest misconceptions is that a carrier pony is a problem. In reality, many buyers see “carrier” and immediately worry.

A carrier pony:

• is not affected
• can be ridden, competed, and enjoyed normally
• only becomes relevant in breeding decisions

In practical terms, many high-quality Connemaras are carriers. Avoiding them entirely would remove a large portion of the breed’s available bloodlines.

What happens if you only breed from N/N (clear) ponies?

At first glance, breeding only from clear ponies seems like the safest option. However, this approach has consequences.

If breeders restrict themselves to N/N ponies only, over time it can lead to:

• A reduced gene pool
• Overuse of a smaller number of stallions
• Increased inbreeding risk
• Loss of valuable traits and bloodlines

For that reason, most breeding programmes support the careful use of carriers, provided they are only bred to clear ponies.

HWSD testing rules for Connemara ponies

Testing for HWSD is now a standard part of Connemara breeding and registration.

Connemara Pony Breeders’ Society (Ireland)

• All foals must have an HWSD status recorded before registration
• If both parents are N/N, the foal can be recorded as clear by parentage
• Otherwise, the foal must be tested

In addition:

• All breeding animals (except geldings) must be tested
• Stallions must have a confirmed HWSD result before approval

Results are recorded in passports and official pedigree records. A pony’s HWSD status does not prevent registration, but it does guide responsible breeding decisions.

British Connemara Pony Society (UK)

• Foals must have an HWSD result recorded before registration
• Foals from two N/N parents may be recorded as clear without testing
• HWSD status is included in the passport

Breeding stallions must have a declared HWSD status, ensuring transparency for breeders and buyers.

Should you avoid buying a HWSD carrier pony?

In most cases, no.

For a riding or competition pony, a carrier is no different from a clear pony in terms of soundness related to HWSD. The condition only becomes relevant if the pony is used for breeding.

What matters more when buying is:

• conformation
• temperament
• performance
• overall health

The HWSD result should be understood, but not overinterpreted.

Read about living with an HWSD Connemara pony

Is HWSD fatal in Connemara ponies?

HWSD itself is not a disease that causes sudden death. However, in affected ponies, it can lead to serious hoof problems that may impact long-term welfare.

Some affected ponies can be managed carefully, but others may struggle to remain comfortable or sound. In more severe cases, quality of life becomes the deciding factor.

Why HWSD is now manageable

Before DNA testing, this condition could appear unexpectedly and be difficult to control. Now, the situation is very different.

With testing:

• every pony’s status can be identified
• risky matings can be avoided
• affected foals do not need to be produced

This makes HWSD one of the more manageable genetic conditions in the breed.

Frequently asked questions about HWSD in Connemaras

Can you ride a HWSD carrier pony?

Yes. A carrier pony is clinically normal and can be ridden, competed, and used like any other pony.

Can two carriers be bred together?

They can, but it should not be done. There is a 25% chance of producing an affected foal.

Is a carrier pony unhealthy?

No. A carrier does not show the disease and is not affected.

Should breeders avoid carriers completely?

No. Responsible use of carriers helps maintain genetic diversity while avoiding affected foals.

What is the safest breeding combination?

Clear × Clear is genetically safest for HWSD, but Carrier × Clear is also safe in terms of avoiding affected foals.

How early can HWSD be seen?

Signs often appear within the first few months of life in affected ponies.

Can HWSD be cured?

No. It is a genetic condition, so it cannot be cured. It can only be managed or prevented through breeding decisions.

Is HWSD common in Connemaras?

The gene exists within the population, which is why testing is now standard practice.

Do all breeders test for HWSD?

Testing is now expected and, in many cases, required for registration and breeding animals.

Why is HWSD status included in passports?

To ensure transparency and allow breeders and buyers to make informed decisions.

Conclusion

HWSD is a serious condition, but it is also one that can be controlled effectively.

With testing and informed breeding decisions, affected foals can be avoided while still maintaining the strength and diversity of the Connemara breed.

For buyers, the key is understanding what the results mean. For breeders, the responsibility is using that information correctly.

Read more Connemara Pony Guides

View Connemara Ponies for sale

View Connemara Stallions for stud