Acquired and congenital pyloric stenosis in dogs

Pyloric stenosis is a conformation problem that can have an acute and profound effect on the overall health of your dog, and make being able to feed them effectively in a way that allows them to digest and get the full benefit from their meals very challenging.

The condition is also referred to in more technical terms as chronic hypertrophic pyloric gastropathy, although the more common term of pyloric stenosis is much easier to remember-and spell! The condition arises when muscles in the region of the body’s pyloric canal-the part of the body that connects the stomach to the duodenum-become overly developed and so, narrows the canal itself so that partially digested food cannot pass through it properly, or alternatively, the pyloric canal itself may simply be naturally too narrow, or narrow over time.

This leads to a range of problems such as vomiting regularly after eating, as the food digested cannot pass through the body in the normal way, which can of course make it very hard to ensure that your dog receives all of the nutrition and calories that they need.

Additionally, regular vomiting will be very debilitating to your dog and so, worsen their general health and condition, as well as contributing to the breakdown and decay of tooth enamel, leading to later dental problems.

While the condition is not hugely common across the dog population as a whole, certain breeds and types of dogs do have higher than normal chances of developing or being born with the condition, and so owners of such breeds are advised to learn a little about the disease, and how to spot its symptoms.

In this article, we will look at pyloric stenosis in dogs in more detail, including the differences between the acquired and congenital versions of the condition respectively, and what type of dogs are at the greatest risk. Read on to learn more.

Acquired and congenital pyloric stenosis

In dogs, pyloric stenosis can be either congenital and so, present from birth to some degree or acquired, meaning that the physiology and internal structure of the dog’s digestive system changes over time and permits the condition to develop.

Dogs suffering from the congenital form of the condition will usually present with symptoms from a relatively young age, although it may not be evident from birth-while dogs with the acquired form of the condition may become symptomatic at any age.

Recognising these two different variants of the condition is important, because the breeds and types of dogs that are at higher risk of being affected by pyloric stenosis are distinct depending on whether or not the acquired or congenital variants of the condition are in play.

What breeds of dog are at risk?

Theoretically any breed or type of dog may potentially develop or be born with pyloric stenosis, although the condition tends to be more common to small and toy dogs than medium and large breeds.

The dog breeds considered to be at higher risk of the congenital form of pyloric stenosis are all flat-faced brachycephalic dogs, such as:

• The English bulldog
• The Boston terrier
• The Boxer

The dog breeds that are considered to be at higher risk of the acquired form of the condition that may not develop until later in life include:

• The Poodle
• The Pekingese
• The Shih Tzu
• The Lhasa Apso

Poodles of all sizes are at risk of the condition, which is particularly interesting because it is otherwise unusual for the condition to be found in medium and large-sized dog breeds.

What causes the condition?

Pyloric stenosis can be caused by two different things-a pyloric canal that is narrower than the norm, or overdeveloped muscles around the pyloric canal that squeeze it and so, narrow it down. However, what leads to either of these two things happening in the first place can be variable, and dogs that are simply born with a narrow pyloric canal can happen due to poor conformation, even if this is not at all evident from looking at the dog.

There are a range of risk factors and situations that can heighten the risk of pyloric stenosis developing and contribute to the disease becoming a problem, including hormone imbalances, gastritis, stress, and as a secondary consequence of various other health conditions including stomach ulcers or cancerous tumour growths.

What are the symptoms of pyloric stenosis in dogs?

Because the digestive system as a whole is such a large part of the dog’s body and is constructed of such a large number of different structures and processes, definitively diagnosing pylori stenosis can be very challenging, and will require a range of examinations and tests to eliminate other differential diagnosis.

However, in small breeds of dog and particularly, breeds that are known to have higher than average risk factors for the condition, competent vets are more likely to consider pyloric stenosis early on as part of their differential diagnosis protocols.

The symptoms that your dog is likely to display at home can be subtle, wide-ranging and common to a range of other problems too, but will almost certainly include regular vomiting after eating-usually within a couple of hours of eating-which may be minor or very acute. As a result of this, your dog is apt to lose weight and condition too, and may be reluctant to eat or not keen to eat much because they know that they are apt to become sick.

Can pyloric stenosis in dogs be treated?

Pyloric stenosis can generally be successfully treated in dogs that are otherwise healthy, by means of open surgery to investigate and correct the problem. After surgery, your vet is also likely to recommend a special diet for your dog in the future that is highly digestible, and that will be easier to process through a narrower than normal pyloric canal.

After surgery, there is a small risk of recurrence in some dogs, particularly if the cause was overdeveloped muscles-this may require a second surgery, which is likely to be more comprehensive than the first in order to avoid a potential third recurrence of the condition.