The Brachycephalic Obstructive Airway Syndrome (BOAS) occurs in dogs of different breeds with pronounced Brachycephaly (Flat-facedness). The disease is one of the most important hereditary defects in dogs. The VDH provides the following health tests to examine dogs for BOAS:



Within the framework of the international cooperation of the leading European members of the FCI, the VDH has successfully advocated the implementation of the Respiratory Function Grading Scheme (RFGS, Cambridge-Test) of the University of Cambridge. All national Kennel Clubs in Europe will introduce the RFGS as an important part of breeding decisions in for Pugs, Bulldogs and French Bulldogs. The test is offered by certified veterinarians in Germany and many other European countries.

Certified Vets (Germany)

The treadmill-based VDH-Fitnesstest was developed by veterinarians at different German universities under the lead of the Veterinary University Hannover to examine dogs of various brachycephalic breeds for BOAS. It provides information about the presence of the disease and can be used as a diagnostic tool for therapeutic decisions and to identify healthy dogs for breeding. The test is available in different veterinary clinics and practices in Germany.

Certified Vets (Germany)

Successful introduction of the “Cambridge-Test” in Germany

On September 9th 2023, an important step in the introduction of the a new diagnostic tool was made in Germany: 25 Veterinarians met at the Veterinary University in Hannover to participate in the implementation of the Respiratory Functional Grading Scheme (Cambridge-Test). The test is an internationally approved examination method for the identification of dogs with Brachycephalic Obstructive Airway Syndrome (BOAS). Dr. Jan-Peter Bach reported on the topic in our VDH-magazin “Unser Rassehund”.

Questions & Answers

General questions

Here you will find answers to the most frequently asked questions about BOAS health tests. If you have a question that has not yet been answered here, please write to us.

With the newly introduced tests, we provide our breeders and exhibitors of brachycephalic breeds with effective and non-invasive examination methods for diagnosing or ruling out the presence of BOAS. These tests can contribute to improved breeding selection and the implementation of relevant legal requirements in breeding and showing.

We expect this method to be an important step towards breeding healthy brachycephalic dogs and preventing more invasive and less suitable measures by the legislator, such as breed bans or breeding bans based on anatomical criteria such as nose length, which do not provide reliable information about respiratory function.

The Brachycephalic Obstructive Airway Syndrome (BOAS) occurs in dogs of various breeds with pronounced brachycephaly (short-nosedness) and is possibly the most important hereditary disease in dogs.

The aim of the Cambridge test and the VDH fitness test is to analyse the respiratory function of dogs of breeds with pronounced brachycephaly. In this way, dogs without impaired respiratory function can be identified for breeding.


The test is available for dogs of the Pug, English and French Bulldog breeds. In Germany, the test may also be carried out on dogs of the Continental Bulldog breed. According to current knowledge, Continental Bulldogs are hardly affected by BOAS, but the FCI prescribes the performance of suitable tests as a condition for the official recognition of the breed beyond Germany and Switzerland.

In the Cambridge test, the dog being tested is subjected to a controlled, sub-maximal exercise load. For this purpose, it is moved at a trot for 3 minutes by the owner or a member of the test team.

Before and after the test, the dog is examined by a veterinarian specially trained for this test. A crucial part of the examination is listening to the pharyngo-laryngeal breathing sounds (pharyngo-laryngeal auscultation, see photo).

As it is a sub-maximal exercise, the test is manageable for the vast majority of dogs. Dogs affected by BOAS show increased breathing noises after the exercise. Studies have shown that 3 minutes of light exercise is sufficient to elicit these breath sounds. Dogs that already show certain breathing noises or signs of respiratory distress before exercise are not subjected to the exercise test. They must be categorised directly as grade 3 (severely affected).

The dog is assigned a result (grade 0 to grade 3) after the examination. Decisive for the assessment are the detected breathing sounds, the breathing pattern shown (in particular possible signs of respiratory distress) or the occurrence of a blue colouration of the mucous membranes (cyanosis) or a type of weakness (syncope).