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Premature closure of the distal ulna (PCDU)

PCDU and INC grading presentation

BREEDERS - Please see the above presentation for information on INC grading of breeding stock

Although the number of Glens diagnosed with this condition is relatively small, PCDU (premature closure of the distal ulna) is a hereditary health issue that can have a significant and ongoing impact on quality of life.

The breed clubs do not yet have any "best practice" guidelines for breeders ... as only a small number of cases have been reported ... but common-sense principles can be applied to try to minimise the risk of producing more Glens affected with this debilitating condition.

N.B. If you are in the UK, please notify the GOITA & EFG health coordinators if your Glen is diagnosed with PCDU ... or has any other foreleg diagnosis, including angular limb deformity (ALD); elbow incongruity; elbow dysplasia; arthritis. 

Owners / breeders: For more detailed information about PCDU and breeding guidelines, please see the box below.


Puppy buyersAsk the breeder about PCDU

The front legs of a Glen


The Glen is an achondroplastic, or more specifically, an osteochondrodysplastic breed i.e. it has characteristics of dwarfism. Glens are normal-sized dogs with dwarfed (short) legs. The Kennel Club Breed Standard (Oct 2009 update) describes the forelegs as being “short, well boned and slightly bowed” with the front feet “to turn out slightly from pastern”.

  • osteo:                 bone   

  • chondro:            cartilage                  

  • dysplasia:          abnormal growth or development


The short, slightly bowed front legs and slightly turned out front feet of the Glen are a characteristic feature of the breed. Using the face of a clock, the front feet should turn out to about 5 minutes to 1 o’clock.


Adult Glen of Imaal Terrier with the characteristic slightly turned out front feet

This photo illustrates the characteristic “slightly” turned out front feet of a Glen.


What is PCDU?


Premature closure of the distal ulna is a complex heritable condition.


PCDU, which is a type of angular limb deformity (ALD), is a condition where the distal growth plate of the ulna closes prematurely, thereby preventing the ulna from growing further. However, the adjacent bone – the radius – continues to grow; and it is this uneven growth that forces the radius to bow (curve and twist) and the wrist to turn out.  


  • Ulna

One of 2 long bones in the lower foreleg, between the elbow and the wrist (carpus)

  • Radius                                  

One of 2 long bones in the lower foreleg, between the elbow and the wrist (carpus) 

  • Growth (epiphyseal) plate        

At either end of the long bones is a growth plate, which allows for lengthening of the long bone through puppyhood

  • “Distal ulna”                          

This refers to the growth plate at the lower end of the ulna i.e. the wrist (carpus)


PCDU is a painful condition that can affect one or both forelegs. The deformity at the wrist (carpus) leads to elbow incongruity (poor alignment of the joint surfaces in the elbow) and subsequent osteoarthritis.

Glen of Imaal Terrier with the excessive turnout of the front feet that is a feature of PCDU

This photo illustrates the excessive turnout of the front feet (carpus valgus) that is a feature of PCDU.

Features of PCDU

The signs of PCDU present during puppyhood, from as early as 3 months of age.

Please be alert to:


  • Lameness in your puppy i.e. persistent limping, which may be intermittent over a period of time, that does not respond to rest

  • Excessive turnout of one or both front feet (carpus valgus)


Limping is a sign of pain, but your puppy may not be limping all the time. The signs below may also be indicators, along with the features above, of your puppy telling you s/he is hurting:


  • Reluctance to go out for a walk … because your puppy associates this with pain

  • Lying down on a walk and refusing to continue after a rest … because it has become painful to walk

  • Licking the inside of his/her paws … because the excessive turnout causes your puppy to walk on the inside of the affected foot


It is important for any young Glen presenting with a history of persistent/intermittent limping and/or excessive turnout of one or both front feet to be checked over by a veterinary surgeon.

N.B. Not all cases of lameness are because of PCDU.  Injury, soft tissue damage and foreign bodies in the paw can also cause lameness. 


  • Surgical treatment for PCDU aims to correct the deformity and so reduce the associated pain. There are different surgical options depending on age and severity of symptoms at diagnosis. Owners may wish to consider referral to a specialist for imaging and surgical management of this complex condition.


  • Conservative, or non-surgical, management of PCDU aims to treat pain and maintain mobility. 


Early interventions will generally result in better long-term outcomes.

Long term outcomes

All Glens with a diagnosis of PCDU will have a degree of osteoarthritis (OA) in the respective elbow joint, even if they have corrective surgery.


Glens that undergo corrective surgery may still need “as required” pain medication for OA, especially as they get older.


Glens that are treated conservatively will need regular review for pain management. Weight management and avoiding long walks will reduce stress on the affected joints.

Young Glen of Imaal Terrier before and after surgery for PCDU

This photo shows a young Glen who was diagnosed with PCDU. She presented with a history of limping and excessive turnout (carpus valgus) of her left foreleg. The picture on the left shows her before surgery and the picture on the right was taken 4 weeks after her corrective surgery.

Breeding guidelines


  • INC grade breeding stock prior to first mating - please see 'PCDU and INC grading presentation' slides 11 & 12

  • Do not breed from a Glen that has been diagnosed with PCDU or has had surgery for PCDU

  • Avoid breeding from a Glen who with a history of (unexplained) persistent/intermittent limping as a puppy

  • Avoid breeding from a Glen with excessive turnout of one or both front feet

  • Avoid repeat matings where any offspring has been diagnosed with PCDU 

Advice to puppy owners


Early intervention generally results in better outcomes, so please seek veterinary advice as soon as possible ...


  • if your puppy starts to limp and this does not resolve with a period of rest

  • if your puppy has an episode of limping that resolves but then starts limping again

  • if you notice that one or both of your puppy’s front feet are turning out more than they should be … see photos above


If your vet suspects PCDU, you may wish to request referral to a vet who specialises in the imaging, treatment and management of this complex condition.

Please do consider having your Glen insured ... at least for 12 months after s/he comes to live with you … to cover this eventuality

and do check that your insurance company covers developmental issues

Please report a diagnosis of PCDU or any other foreleg diagnosis, to the GOITA & EFG health coordinators
Please also notify your breeder, so that repeat matings can be avoided.

Photos used with kind permission of owners

With thanks to Dr Martin Owen BSc BVSc PhD DSAS(O) Dip. ECVS MRCVS, East of England Veterinary Specialists Ltd., for his help with this article

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