Exercise-Induced Collapse, EIC (Exercise-Induced Weakness in Labradors) in Dogs

  • Occurrence: very rare
  • Location of illness: General/Whole body
Content
Download/Print

Exercise-Induced Collapse (EIC) is a genetic condition that causes dogs, especially Labrador Retrievers, to suddenly collapse after intense physical activity. It is characterized by hind limb weakness and, in severe cases, complete collapse.

The most important facts at a glance

Exercise-Induced Collapse (EIC) is a genetic condition in dogs that primarily affects Labrador Retrievers. It is caused by a mutation in the Dynamin 1 (DNM1) gene, which is important for the normal function of the nervous system. The disease is inherited in an autosomal recessive manner, meaning that dogs must have two copies of the defective gene to show symptoms. These symptoms include muscle weakness and immobility after intense physical activity, with dogs often recovering within 20 minutes. Seizures may also rarely occur. A definitive diagnosis can be made by a genetic test that detects the presence of the DNM1 mutation. There is no cure for EIC, but the symptoms can be controlled by managing physical activity. Intense exertion should be avoided, and in the event of a collapse, dogs should be cooled and kept calm immediately. The prognosis depends on the owner’s ability to monitor activity; many dogs can still live a normal life. Prevention is achieved through genetic testing in breeding to minimize the transmission of the mutation. Owners of dogs at risk of EIC should closely monitor their dog’s activity to reduce the risk of collapse, and regular veterinary check-ups are recommended.

Causes

The scientific basis of EIC is closely linked to genetic factors. The disease is inherited in an autosomal recessive manner, meaning that a dog must have two copies of the defective gene to show symptoms. The gene involved is the Dynamin 1 (DNM1) gene, which plays a crucial role in the nervous system. It is responsible for synaptic vesicle endocytosis, a process essential for normal nerve function.

In dogs with EIC, a mutation in the DNM1 gene leads to a loss of function of this protein, which impairs the ability of neurons to respond efficiently to repeated stimulation. This can lead to a temporary dysfunction of neuromuscular transmission, especially during or after intense physical activity.

The exact prevalence of EIC is not fully known, but studies show that it is relatively common in Labrador Retrievers. In addition to Labradors, other breeds may also be affected, but less frequently. The mutation in the DNM1 gene is the main trigger for this disease, and genetic testing of breeding animals is increasingly seen as an important tool for controlling the spread of the disease within the population.

Symptoms

Rare symptoms:

The symptoms of EIC typically occur in young dogs aged 5 months to 3 years who are physically active. The first signs are often weakness or uncertainty / disorientation in the hind legs, which occurs during or shortly after intense exercise. Affected dogs may stumble, stagger, or suddenly collapse.

The collapse itself is usually not painful, and the dogs remain conscious and responsive to stimuli. The symptoms usually subside within 5 to 25 minutes after stopping the activity, as long as the dog can rest. In severe cases, however, the collapse can be life-threatening, especially if the dog does not get immediate rest.

It is important to note that not all dogs with the DNM1 gene mutation show symptoms. The severity of symptoms can vary from dog to dog, and some may live their entire lives without obvious problems, while others experience regular collapse episodes.

Diagnosis

The diagnosis of EIC is primarily based on clinical history and characteristic symptoms. A veterinarian will ask about the nature of the symptoms, their occurrence in connection with physical activity, and the dog’s genetic history.

A definitive diagnosis can be made by a genetic test that checks for the presence of the specific mutation in the DNM1 gene. This test is simple and non-invasive, as it typically requires a blood sample or a swab from the oral mucosa.

Other diagnostic tests can be performed to rule out other possible causes of the collapse, such as cardiovascular disease, metabolic disorders, or neurological problems. These may include blood tests, ECG, X-rays, or MRI.

Therapy

There is no cure for EIC, but the symptoms can be controlled by managing the dog’s physical activity. The main treatment is to avoid intense physical exertion that could trigger a collapse.

Owners of dogs with EIC should watch for signs of lethargy or weakness and stop training immediately to prevent a complete collapse. In some cases, short, controlled exercise sessions under close supervision can be helpful to maintain the dog’s fitness without provoking symptoms.

In emergencies, if a dog collapses, it should immediately be moved to the shade and cooled, e.g. by spraying it with water. It is important to keep the dog calm and allow it time to recover.

Prognosis and follow-up care

The prognosis for dogs with EIC varies depending on the severity of the symptoms and the owner’s ability to manage the dog’s physical activity. Many dogs can live a normal, happy life if seizures are avoided through appropriate measures.

However, some dogs are at risk of life-threatening collapse, especially if they exert themselves intensely unsupervised. Therefore, it is crucial that owners are aware of the condition and take appropriate precautions.

Prevention

Since EIC is genetic, the key to prevention lies in genetic control within breeding populations. Through targeted breeding strategies based on genetic testing, the risk of passing the mutation on to future generations can be reduced.

Breeders should have potential breeding animals tested for the DNM1 mutation and consider the results when selecting mating partners. The aim is to minimize the spread of the mutation in the population by not using carriers and affected animals for breeding.

For owners of dogs with known EIC risk, it is advisable to monitor the dog’s physical activity and adjust it if necessary to minimize the risk of collapse. Regular veterinary check-ups and working with a veterinarian can also help ensure the dog’s well-being.

Content
Download/Print