Health Matters

It certainly does to us and it should matter to anyone wanting to own a Great Dane, anyone that does already own a Great Dane and any one wishing to breed a Great Dane. There is a lot of information about health issues on the internet but its hard to find information as to how many Danes these issues effect. Talk to anyone who has had Danes for some time and they will be able to tell you what issues they have encountered, but can they tell you how many other Danes have the same problem.

We have chosen to use data obtain from health surveys to list here breed problems. This list of course does not detail every problem that has ever affected the breed but ones that based on this data, are shown to be the biggest issues for Great Danes. You can read the full health survey used by selection each of the reports. One was completed by the Kennel Club in 2006 the other by the Great Dane Club of America and as you would exspect is more in depth.

Gastric dilatation-volvulus (GDV) is a very serious condition that occurs in many large deep chested dogs when the stomach becomes distended with air, and then whilst enlarged, twists on itself. This interferes with the blood supply to the stomach and other digestive organs, and blocks the passage of food, leading to worse bloat. The distended stomach impedes the normal return of blood to the heart, causing drastically reduced cardiac output and a decrease in blood pressure. Blood/oxygen-deprived tissues start to die, releasing toxins into the blood stream which among other adverse effects, cause serious disturbances in heart rhythms (cardiac arrhythmias) - a common cause of death in these dogs.

Simple gastric dilatation does not produce volvulus (twisting) in an otherwise normal stomach. Dogs most susceptible to GDV are the large, deep-chested breeds, in whom the stomach appears to be more mobile within the abdomen. Other factors that increase the risk for GDV include overeating, rapid eating, single daily feeding, high water consumption, stress, and exercise after eating.

What does gastric dilatation-volvulus mean to your dog & you?

GDV is one of those thankfully rare conditions in which your dog can go from being healthy to critically ill over the course of a few hours. Even with appropriate veterinary care, approximately one third of dogs with this condition will die

When gas first starts to accumulate in the stomach, the dog will appear slightly uncomfortable. The stomach then starts to dilate (gastric dilation) and the dog will become anxious and restless, often pacing, and the stomach may be swollen. He may also try to vomit, but will only bring up a white foam, no food.

The next stage is when the stomach twists (gastric volvulus) and the dog becomes extremely restless, whining and panting as well as salivating and trying to vomit every few minutes. He may go on to stand with his legs apart and hang his head down. The stomach is swollen and sounds hollow if tapped.

When the blood supply is cut off, organs become compressed and shock can begin to develop. The dog is unable to stand, or stands very shakily, with his legs apart. The stomach is very swollen and breathing is shallow.

The final stage is shock and heart failure develops, the dogs gums are white or blue and death is imminent.

How is gastric dilatation-volvulus diagnosed?

GDV must be diagnosed and treatment initiated quickly if your dog is to survive. The condition is usually readily diagnosed on physical examination. The best chance a dog has of surviving is immediate veterinary attention. Sadly, even with treatment, a large percentage of dogs still die, some survive surgery but then die of the shock after treatment.

Your veterinarian must relieve the pressure, decompressing either by using a stomach tube or inserting a large needle into the stomach to release the gas. The less time the pressure is on the stomach and organs the better the dog's chances of survival. Once the dog is stabile, x-rays are taken to determine whether a torsion is present. If it is, then surgery is performed to untwist the stomach, which is then stitched to the abdominal wall to prevent reoccurrence.

How is gastric dilatation-volvulus treated?

Your veterinarian must relieve the pressure, decompressing either by using a stomach tube or inserting a large needle into the stomach to release the gas. The less time the pressure is on the stomach and organs the better the dog's chances of survival. Once the dog is stabile, x-rays are taken to determine whether a torsion is present. If it is, then surgery is performed to untwist the stomach, which is then stitched to the abdominal wall to prevent reoccurrence.

Intensive care is required in the immediate post-operative period when dogs may face a number of life-threatening problems including shock, electrolyte imbalance, cardiac arrhythmias, and wide-spread infection (septicemia).

Prevention

There are some simple things you can do to reduce the chance of bloat. Basically, you want to avoid your dog consuming a large amount of food or water all at once, especially not at the same time as vigorous exercise. Rather than feeding once a day or leaving food always available, feed in divided portions. Avoid exercising your dog before and after meal times.

Most important of all, ensure you know and can recognise the symptoms of bloat and act quickly by taking him to the vet immediately.

Cardiomyopathy refers to disease of the heart muscle (the myocardium) without malformation of the heart or its valves. There is a breed predisposition to dilated cardiomyopathy in giant breeds. Cardiomyopathy can also develop as a result of some toxins or infections.

There are three type of Cardiomyopathy, but dilated cardiomyopathy (DCM) is by far the most common type in Great Danes. There is dilation of the chambers of the ventricles of the heart with some increase (hypertrophy) in the heart muscle mass, and a loss of the normal contracting abilities of the ventricles.

The heart works harder to compensate for the loss of contractility, eventually leading to congestive heart failure. The abnormalities in the heart muscle cells give rise to irregular heart rhythms which may cause sudden death.
How is cardiomyopathy inherited?

The pattern of inheritance is not yet know, but there is evidence to suggest that its more common in males.
What does cardiomyopathy mean for you and your dog?

Danes with dilated cardiomyopathy typically show signs associated with abnormalities of heart rhythm (particularly atrial fibrillation) and generalized heart failure. These signs may include weakness, loss of appetite, weight loss, depression, episodes of collapse, respiratory difficulties, a soft cough (especially at rest), and an enlarged abdomen. There is severe enlargement of all 4 chambers of the heart. Dogs are affected in middle-age on average, although they may be affected as early as a few months of age. Abnormalities may be seen on an electrocardiogram before there are any clinical signs.

For all Danes with dilated cardiomyopathy, the arrhythmias that can cause fainting or collapse can also cause sudden death. Up to 50% of affected dogs die suddenly, often without having shown any other signs of the disorder.
Once dogs with cardiomyopathy develop congestive heart failure, the prognosis is poor.

How is cardiomyopathy diagnosed?

X-rays generally show an enlarged heart, predominantly on the left side.
There may however be no abnormalities on radiographs, on physical exam, or on the resting electrogardiogram. A heart scan (echo) is the only way to definitively diagnose DCM. If cardiomyopathy is suspected and all routine diagnostic tests are normal, a 24 hour ambulatory electrocardiogram ( a Holter monitor) is recommended. The unobtrusive monitor is worn by the dog during its normal activities, and records irregular heart rhythms.

How is cardiomyopathy treated?

Decisions about treatment are based on several factors: whether the dog is showing clinical signs such as weakness or collapse, what arrhythmias are seen on the electrocardiogram, and whether congestive heart failure is present. If your dog has an abnormal heart rhythm without any evidence of congestive heart failure, your veterinarian may prescribe anti-arrhythmic drugs, depending on the severity of the arrhythmia.

Episodes of collapse indicate a serious arrhythmia and must be treated as an emergency.
Treatment for dogs with signs of congestive heart failure involves rest, diet restrictions, and drugs to stabilize and support the failing heart as well as to control the arrhythmias. If low doses of anti-arrhythmic drugs are effective, then the heart can often be stabilized. Serious ventricular arrhythmias that can only be controlled by high doses of anti-arrhythmic drugs have a poorer prognosis.

Breeding advice

Affected individuals and their parents should not be used for breeding. Siblings should only be used after careful screening.

How can cardiomyopathy be controlled?

There are ways to approach the control of this disease. Although signs of heart failure are often not evident until middle age, abnormalities on the electrocardiogram are often apparent earlier. Danes with a family history of cardiomyopathy, breeding animals should be evaluated yearly for evidence of cardiac arryhthmias, using an ambulatory (Holter) monitor if possible. Dogs in which occult dilated cardiomyopathy has been identified (ie. no clinical signs) should not be used for breeding.