Pug Dog Encephalitis (PDE)

Pugs are one of the most instantly recognisable and most popular small dog breeds in the UK, thanks to their unusual appearance and winning personalities; however, they are also one of the breeds most apt to be affected by a wide plethora of different health issues that are either hereditary or caused by their conformation.

One condition that is of particular concern to pug owners and that poses a significant risk to the health of the breed as a whole is pug dog encephalitis. This neurological condition can be very painful for affected dogs as well as potentially causing seizures, and that is one of the largest problems within the breed as a whole, which dramatically shortens the dog’s lifespan as well as impacting on their quality of life.

Encephalitis comes in many different forms, and most of them are caused to infections that affect the brain; however, pug dog encephalitis is different, in that it is an immune-mediated hereditary health condition that can be passed on through the breed line from dog to dog.

Immune mediated conditions are particularly challenging to manage, as they essentially lead to the dog’s own immune system turning on its own body, producing an inappropriate immune response that attacks the dog’s normal, healthy tissue.

In this article, we will look at pug dog encephalitis in more detail, including how the condition affects dogs, how to get your dog tested for the condition, and how the heredity of the condition works. Read on to learn more.

More about pug dog encephalitis

Pug dog encephalitis usually becomes symptomatic in affected pugs when they are aged between two and three, although the age of onset can be highly variable, being as early as six months old in some cases and over six in others.

The progression rate of the condition can be very variable as well, with some dogs going from fine to seriously ill within just a few weeks, and then dying suddenly. However, in other dogs, the condition can take months or in rare cases, even years to become fatal, and in the meantime, pug dog encephalitis can be managed to some degree with the use of seizure medications.

The symptoms of the condition include weakness and lethargy, depression, confusion and the un-learning of learned behaviours, as well as a range of other behavioural changes too.

Physical indicators of the condition can include head tilting and stiffness of the neck, as well as in some cases head pressing, in which the dog will press their forehead against a solid object to attempt to relieve the pressure in their skulls.

Seizures also manifest as the condition progresses, sometimes from the earliest stages, and in some presentations, the first seizure may be the first indication of the condition’s presence.

What sort of dogs are at greatest risk of the condition?

All dogs of the pug breed are considered to be at potential risk of the condition, unless they have been tested for their status and been determined as clear; or, if the status of both parent dogs was ascertained prior to mating.

Additionally, crossbreed dogs with one pug ancestor are at potential risk too, although to a much lesser extent thanks to the benefits of hybrid vigour.

Pug dog encephalitis is the cause of death of around 1% of all pugs in the UK, although a significantly higher number may be carriers of the condition. Female pugs with fawn colouring are slightly more likely to develop the condition than males, and pugs of other colours.

How does the heredity of the condition work?

Pug dog encephalitis is inherited by means of autosomal recessive heredity, which means that for a dog to be affected by the condition, they need to inherit a specific combination of mutated genes from both sides of their parentage. However, unaffected dogs may still potentially be carriers for the condition, and so run the risk of passing it on to their own litters.

Dogs are designated with one of three statuses for the condition: Clear, carrier or affected. Knowing the status of the parent dogs allows you to ascertain the status of their potential litter too, according to the following table:

• Two clear dogs will have a clear litter.
• Two affected dogs will have an affected litter.
• Two carriers will have a mixed litter of 50% carriers, 25% clear and 25% affected.
• A clear dog and a carrier will have 50% clear and 50% carrier puppies.
• A clear dog and an affected dog will have a litter of carriers.
• A carrier and an affected dog will have 50% carriers and 50% affected.

How to get your dog tested

In order to find out your own dog’s status, you just need to ask your vet to take a DNA sample from your dog, in the form of a buccal swab or a vial of blood. This is then sent off to one of The Kennel Club’s approved laboratories for testing, and they will then return the results to you.