Welsh Terrier Club

Welsh Terrier Breed Health


from the Neurology and Neurosurgery Service of the Royal Veterinary College

Foreword: This condition is known in Border Terriers, but several cases in Welsh Terriers have recently become known.


15th December 2022 - an article was reported by Veterinary Neurology -


A recent study by Dr Danielle Whittaker and the team at the RVC in London, published in The Veterinary Journal, has highlighted a potentially heritable movement disorder in Welsh Terriers. Paroxysmal dyskinesia (PD) is an 'umbrella' term for disorders characterized by recurrent episodes of involuntary and abnormal movement or muscle tone with variable duration. Multiple breeds have now been documented with PD.


In this study, the episodes were predominantly characterized by sustained hypertonicity with periods of limb flexion, abnormal head and body posture, with preserved consciousness. Episode duration ranged from 30s to 30 min (median, 3 min 30 s), with frequency varying widely between dogs.


Affected dogs demonstrated a stable to improving clinical course in most cases. A third of dogs exhibited gastrointestinal signs following episodes, including vomiting, diarrhoea, flatulence and borborygmi similar to Border terrier dogs that have a paroxysmal gluten sensitive dyskinesia.


For the full report - https://doi.org/10.1016/j.tvjl.2022.105801


Laurent Garosi Simon Platt



15th September 2017

We have recently seen several Welsh Terriers with a type of suspected movement
disorder.  It is also termed “paroxysmal dyskinesia”.


Movement disorders are characterized by episodes of abnormal limb and body movements, and are increasingly recognised in veterinary medicine. These disorders are typically breed specific. They are challenging to diagnose and tend to involve sporadic, isolated episodes of disturbed movement without loss of consciousness.  Affected dogs will appear completely normal between episodes.

The most recent thinking in human and veterinary medicine is that these represent a temporary dysfunction in a part of the brain that controls movement.


In the Welsh Terriers that have presented these symptoms, the disorder has been characterised by episodes as mentioned above,  involving abnormal body/trunk posture and sustained limb elevation and can be distressing to witness.


The episodes we have seen can last for several minutes, but it is possible that there is variation in episode length from seconds to hours in some dogs.  Similar episodes have sometimes been described as seizure-like; however, on examination of video footage, they are more consistent with a movement disorder.

Due to the shared symptoms between the cases seen at the Neurology and Neurosurgery Service at the Royal Veterinary College, we suspect that it may represent a condition that IS breed specific, potentially with a genetic cause.


We are therefore aiming to further characterise the disorder in the wider Welsh Terrier population, with the objective of increasing awareness or recognition in this breed. 

We also have a long-term aim of investigating contributive factors, including a potential genetic origin. Eventually, we hope to determine if specific treatment or management options are effective.


29th April 2020

Research is still ongoing by the Royal Veterinary College; we are awaiting the article with their findings to be published in the veterinary journal.


Primary Glaucoma/ Goniodysgenesis           by Alexandra Witmond     January 2018


**UPDATE DECEMBER 2019**  Goniodysgenesis/ primary glaucoma (G) -  I have been advised by the Kennel Club that Welsh Terriers will no longer be listed under Schedule B of the eye scheme for this condition with effect from1st January 2020. This is due to the fact that, over time, there have been very few reports of this condition in the breed, which has consequentially suggested that the breed is not, at this time, predisposed to the condition.


Primary Glaucoma is a painful and blinding disease associated with intraocular pressure (high pressure inside the eye). It is an inherited condition and is sub divided into two types:
(1) primary open angle glaucoma and
(2) closed angle glaucoma.

In both forms, glaucoma results from reduced drainage of the fluid (aqueous humour) that is produced within the eye resulting in a build-up of intraocular pressure which in turn leads to pain and blindness. Welsh Terriers are among several breeds where closed angle glaucoma is significantly associated with an abnormality within the eye called Goniodysgenesis. In Welsh Terriers Goniodysgenesis is suspected of being inherited, and Welsh are on the Schedule B of the BVA/KC/ISDS eye scheme.  It is tested for by a technique called Gonioscopy.

Gonioscopy is generally performed without dilation of the pupil and an application of anaesthetic drops is applied to the eyes .The Vet Ophthalmologist will place a special lens on the surface of the cornea to enable the area of the eye to be examined.


Up to the end of 2017 the dog was either (a) Clinically Affected or (b) Clinically Unaffected. Now from 1st of January 2018 a new grading scheme has been introduced grading from 0 – 3:

  1. Grade 0 - clear 0%-1% - normal
  2. Grade 1 - clear / mildly affected, unlikely to develop primary Glaucoma. 1%-25%.

       Both suitable for breeding

  1. Grade 2 -low risk of developing primary glaucoma. 26%-75%

       Specific advice required for breeding.

  1. Grade 3 - severely affected, >75%. High risk of developing primary glaucoma

       Not recommended for breeding


At Manchester Championship Show this year, I took my two Welsh Terrier boys, Kevin and Ricky, along to the clinic, no appointment being necessary. Drops were put in and we were taken into a darkened room where the vet examined the eye. Not at all scary, both boys took it in their stride. Results are given straight away; pleased to say that both were clear. Paper work is needed, so do take along your KC registration papers as this will be correlated to the eye scheme.

For me, these tests are important especially as both my boys are used as stud dogs, so I felt that, as the Breed health co-coordinator, I’d better start the ball rolling. Both dogs are also PLL clear.

Examination for Goniodysgenesis can be done from 6 months old. The cost is between £40-60. Eye clinics are held around the country and at some Championship shows, and are listed in Our Dogs paper - or contact:

    • Canine Health Schemes, British Veterinary Association Tel: 02079806380
    • The Kennel Club: Tel 08444633980


      Masticatory Muscle Myositis is an autoimmune disorder in which antibodies attack the 2M fibres in the masticatory (chewing) muscle group.

      Although MMM can occur in any breed, it occurs more commonly in large breeds such as Golden Retrievers, Doberman Pinschers, German Shepherds, and Labrador Retrievers. Young Cavalier King Charles Spaniels may be severely affected.

      The condition occurs in males and females with an average age of onset of 3 years, though puppies as young as 4 months have been affected. Fortunately, if MMM is diagnosed early, dogs can be treated to increase the likelihood of a full recovery.

      Research of this disease at the University of California San Diego led to the development of a blood test in 2004 that detects the presence of 2M antibodies and accurately identifies affected dogs. The team identified type 2M fibres in the Masticatory muscle group and showed that antibodies against type 2M fibres are involved in the pathogenesis of MMM.

      MMM is an inflammatory myopathy. It is a unique myopathy or a muscle disease in which dogs commonly have jaw pain and inability to open the jaw.

      The genetic components of autoimmune disease are very complex. Although a great deal of research has been done to identify the causes of human autoimmune disease, much less research has been done in dogs. Genes play a role in increasing susceptibility to autoimmune disease but ENVIROMENTAL triggers initiate the onset of clinical signs.

      In dogs that are predisposed to autoimmune reactions, suspect triggers include viral and bacterial exposures, possibly vaccinations, hormones, stress, allergens, medications, and environmental toxins. It is NOT purely a genetic disease - hormonal, environmental and other unknown factors come into play .

      Owners who recognize these signs of MMM in their dogs should seek veterinary care:

      1) Inability to open the jaw.
      2) Jaw pain.
      3) Swelling or atrophy of the jaw muscle.
      4) Difficulty in eating or drinking.
      5) Reluctance to play with toys.
      6) Sunken or protruding eyes.
      If the disease is diagnosed early and a dog is treated appropriately the prognosis is good for
      dogs with MMM.

      Regarding breeding recommendations; MMM is not considered to be a high priority disease to target reduction. This is due to the genetic and environmental complexities, the low incidence of the disease, the overall good outcome with appropriate therapy and, importantly, the concern for maintaining as much genetic diversity in the breed.



      Since March 2012 a genetic condition has come to light that affects Welsh Terriers. It’s called Primary Lens Luxation (PLL).

      This condition is caused by an inherited mutation in a gene which is required for the healthy construction of the lens fibres. PLL is an inherited eye disease which can lead to blindness. In affected dogs, the tiny fibres which hold the lens break down and the lens can fall out of position which may cause glaucoma and blindness. This is a late onset condition – an affected dog would develop signs of PLL between 4 to 8 years of age.

      Thankfully, there is a test for identification of the DNA mutation which has only been available since 2009. This test is useful for those breeders, or pet owners who want to breed, to identify the status of their breeding stock, so that they are not breeding from affected animals as affected dogs should not be bred from.

      There can be three results–
      • CLEAR – free of the PLL mutation
      • CARRIER – has one copy of the mutation
      • AFFECTED – has two copies of the mutation

      As we have a small gene pool in Welsh Terriers, CARRIERS can be used for breeding but only to CLEAR animals, then the pups should be tested; CARRIERS X CLEAR = 50% CARRIER / 50% CLEAR.

      The Kennel club announced that, from 29th August 2013, testing results which qualify for the Kennel Club's DNA Screening Schemes will be accepted from Animal DNA Diagnostics Ltd who carry out this PLL screening, and will be posted on the Kennel Club website. Future results will routinely be forwarded without the need for owners to contact the Kennel Club.

    • This test is not yet a requirement of the Kennel Club, but a lot of breeders having been doing the test to their stock on a voluntary basis.


      October 2017 - Update
      We have now had feedback from Animal DNA Diagnostics:  in the years that this service has been available, 129 Welsh Terriers have been tested – of which 87 (68%) are clear, 38 (29%) are carriers and just 4 (3%) are affected.

    • More information , covering breeding advice, on the Animal Health Trust’s website -