Masticatory muscle myositis in the Welsh terrier

The Welsh terrier is one of the less well-known and not so commonly seen terrier breeds in the UK, but as one of our native dog breeds, they are certainly one that is worth considering if you are looking for a new dog to join your family.

Welsh terriers are a small breed that share all of the best-known terrier traits, including tenacity, a strong prey drive, and an independent streak a mile wide! Dogs of the breed were originally bred and used for working purposes to help to cull rat populations and manage other vermin, but today, they are much more commonly kept as pets.

These little dogs are above average in the intelligence stakes and are very quick-witted and able to think ahead, and they also need a lot of exercise every day to keep them happy and fulfilled. One other notable point to bear in mind about the Welsh terrier is that they have developed a reputation for being very good with children too, which makes them an excellent choice of pet for lively, active families.

Welsh terriers tend to live for an average lifespan of around 12-13 years, and there are a number of congenital and hereditary health problems that dogs of the breed can be prone to. Anyone considering buying or adopting a Welsh terrier puppy should make sure that they find out about the hereditary risk factors that can be found within the breed, and learn a little about the main Welsh terrier health conditions.

One health condition that can be found across some Welsh terrier breed populations is called masticatory muscle myositis, and this condition can be very acute in onset as well as very painful for affected dogs, and of course, distressing for their owners. In this article we will look at masticatory muscle myositis in the Welsh terrier in more detail, covering the symptoms, prognosis, and risk factors for the condition to get you started. Read on to learn more.

What is masticatory muscle myositis?

Masticatory muscle myositis or MMM for short is a type of immune disorder that causes the dog’s own immune system to see parts of its own muscle tissue as a threat, and so, attack it. The muscles involved in MMM are the dog’s masticatory muscles – the muscles of the face and jaw that the dog uses to chew and move their mouth.

When a dog has an attack of masticatory muscle myositis, the muscles of their jaw become painful, inflamed and swollen, and the dog will often be unable to open their mouths at all due to the pain involved. This stops them from opening and closing their mouths normally and means that they cannot chew, eat, mouth, or pick up toys.

Masticatory muscle myositis in the Welsh terrier is a hereditary condition, and affected dogs inherit a predisposition to it from their own parents. However, external factors can trigger the condition in dogs predisposed to it, and these triggers can be quite variable, ranging from stress to bacterial or viral infections, and the full range of potential triggers of MMM in Welsh terriers aren’t definitively known.

What are the symptoms of masticatory muscle myositis in the Welsh terrier?

Masticatory muscle myositis in the Welsh terrier usually develops over a period of time before becoming highly pronounced and painful for the dog, and often the early symptoms are subtle and easy to miss.

During the earliest stages of masticatory muscle myositis development, the dog’s jaw and the sides of their face where their chewing muscles are located may become noticeably swollen and may feel slightly warm to the touch. As the condition develops and worsens, the affected muscles start to waste, which can actually have a visible impact on the shape and appearance of the dog’s head and skull, and which can make the eyes appear to be deeply sunken into their sockets.

When masticatory muscle myositis becomes acute, the dog will be virtually unable to open their mouth because it hurts so much, and this extreme pain and reluctance to open the mouth are highly indicative of the condition.

Contact your vet as soon as you identify symptoms, in order to get a formal diagnosis. To confirm or rule our masticatory muscle myositis in the Welsh terrier, your vet may need to biopsy the affected muscles to determine how inflamed the tissue is, and how badly it has deteriorated. Alternatively, they may use a special blood test to identify the markers of the condition, although this specific blood test is a fairly new advancement that is not yet widely offered within the UK.

Can masticatory muscle myositis be treated or cured?

Generally, masticatory muscle myositis is managed with medications, generally a corticosteroid delivered in a high enough dose over a long enough period of time to achieve remission from the disorder. When your dog’s MMM has gone into remission, a much lower maintenance dose of the medication may be required throughout the remainder of the dog’s life, but in some cases, dogs will recover fully and won’t require medication.

However, even if a dog has been treated successfully and is able to continue without medication, their owners should remain vigilant to the warning signs of future flare-ups, and intervene quickly if the dog becomes symptomatic again.

You will also likely need to make changes to your dog’s diet, feeding them softer foods that require less crunching and chewing and so, that place less pressure on the jaw muscles.

Dogs with masticatory muscle myositis can pass the condition on to their own offspring, and so should not be bred from. If you are considering buying a Welsh terrier puppy yourself, ensure that you ask the breeder about any presentations of the condition within their blood lines.