Giant Schnauzer Health

What is DCM?

This type of DCM is a serious and most often fatal heart condition diagnosed in young Giant Schnauzers, causing swelling of the lower chambers of the heart (ventricles). The heart’s ability to pump blood is reduced since the heart becomes enlarged, and can no longer beat effectively. Genetic analysis of 3 affected UK pepper/salt Giant Schnauzer littermates from European breeding, along with their close relatives, took place at the University of Missouri during 2014. Results from this research found the same mutation as presented in Standard Schnauzers i.e. RBM20 mutation.

Prevalence

Data provided by Laboklin (2024) from across Europe, including the UK, shows that 2% of Giant Schnauzers carry one copy of the mutation, and <1% are affected having 2 copies.

Age of Onset

Dilated cardiomyopathy (DCM) is the most common myocardial disorder of dogs, typically affecting older dogs, however this type of DCM identified by the RBM20 gene mutation occurs in young dogs, and symptoms may begin as early as 1-2 years of age.

Mode of Inheritance

The disease is an autosomal-recessive condition. This means that dogs that inherit two copies of the gene mutation (one from its mother and one from its father) will develop the condition.

Signs & Symptoms

Signs of this disease can include dogs becoming tired or going off their food, they may develop a cough especially during exercise, find it difficult to breathe, fainting or collapsing and progressive abdominal swelling.

Diagnosis

If your vet suspects your dog has DCM, they may want to run some of the following tests to confirm the diagnosis:

• An ECG to check your dog’s heart rhythm (if they have DCM, they may have an arrhythmia/irregular heartbeat).
• An ultrasound scan to see inside your dog’s heart (if they have DCM, your vet will be able to see thin heart walls, enlarged chambers, and your dog’s heart struggling to pump).
• X-rays. If your dog has DCM, their heart is likely to be bigger than normal on x-rays, and there may be fluid on their lungs (a sign of heart failure).
• Blood tests such as ‘ProBNP’, a chemical that shows if the heart muscle is being stretched and struggling to pump blood.
• A DNA test for this type of DCM can also be diagnostic for the condition

Prognosis

DCM can’t be cured, but there are heart medications that can be used to slow it down and help control the symptoms it causes. The treatment your dog needs will depend on what stage of DCM. Characteristic findings of DCM include progressive dilation of the left or both ventricles with concurrent systolic dysfunction with eventual development of congestive heart failure or sudden death. Unfortunately, it’s impossible for anyone to predict exactly how long your dog will live because each case may be different. Some dogs live for several years (especially if they are diagnosed and treated early), but others (with severe DCM/heart failure), only live a few weeks. It’s important to be aware that although there are medications available to help control the symptoms of DCM, it’s a serious condition that in most cases, shortens life expectancy.

To comply with the Kennel Club’s ‘Best Practice’ breeders should DNA test for DCM prior to breeding

Where to go for a DNA Test

See the list of KC approved DNA testing laboratories:

Costs

The Giant Schnauzer Club have a discount voucher code for the Laboklin Giant Schnauzer bundle which consists of: HUU, prcd-PRA, DCM, PRA5 & DM

Contact the breed health co-ordinator for more information

Requirements for the DNA test

1. The dog should be microchipped
2. The Kennel Club require at least two forms of identification on the result certificate. These must include the dog’s microchip or tattoo number along with either the dog’s registered name or their registered number.
3. Results must be of a recognised DNA test and from an approved laboratory for the result to be officially recorded by the KC.

Publication of Results

DCM is part of the official KC DNA Testing Scheme, and as such DNA test results can be added to the KC database for official reporting.

Advice for Puppy Buyers

Ideally choose a breeder where the sire and dam have been DNA tested. If one parent is a carrier or affected the other parent must be CLEAR.

Two carriers, two affected, or a carrier and an affected should not be bred together, as this will produce affected puppies.

Ask the breeder to provide information on the DNA status of a puppy and/or both parents. You can also check on the Kennel Club website link below.

Kennel Club Health Test Result Finder

DNA test results are published for this condition via the Kennel Club health test results finder.

Advice for Breeders

In order to meet the Kennel Club’s ‘Best Practice’ Breeders should DNA test for DCM before breeding.

If you have already had your Giant DCM DNA tested you can now send the results to the KC for officially recording.

Email test certificates to: health.results@thekennelclub.org.uk

Data from Laboklin shows that Giant Schnauzers can carry the DCM mutation, therefore it is important to test before breeding to know which dogs are carriers, and be able to breed safely. If you haven’t tested it’s not possible to know!

The DNA test can prevent puppies from being affected by this mutation.

The mode of inheritance for DCM is a simple autosomal recessive gene. Therefore both the parents that produced an affected puppy would either have one or two copies of the mutant gene.

See breeding from a DNA Tested Dog

The probabilities of producing affected puppies from a simple autosomal recessive inheritance are shown below (actual numerical values will vary)

A ‘Clear‘ has 2 copies of the normal gene, is unaffected and cannot pass on a faulty gene.

A ‘Carrier‘ has 1 normal gene and 1 recessive abnormal gene, they are physically unaffected but may pass on the abnormal gene.

‘Affected‘ dogs have 2 copies of the defective gene of which they will pass on 1 of the affected genes to their offspring.

A mating that may produce affected puppies should not be carried out.

Make a Donation to the GSHF

The purpose of the GSHF is to provide monies for research into inherited health problems in the Giant Schnauzer. All donations gratefully received.

Make a donation…