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Digitalis

Digitalis is a group of active substances extracted from the foxglove. They are mainly used to treat cardiac arrhythmias, but can also be very toxic. In this article, you will find out what digitalis is, how it works, what its benefits and disadvantages are and how you can protect your dog from poisoning.

What is digitalis?

Digitalis is the generic term for various cardiac glycosides that can be isolated from different types of foxglove (digitalis). The best known are digoxin and digitoxin. Cardiac glycosides are substances that act directly on the heart muscle and increase its contractility. They also slow down the heart rate and have antiarrhythmic effects, i.e. they can normalize irregular heartbeats.

How does digitalis work?

Digitalis binds to an enzyme in the cell membrane of the heart muscle that transports sodium and potassium. This disrupts the transport and the sodium concentration in the cell increases. This in turn influences another transporter that exchanges sodium for calcium. As a result, more calcium enters the cell, which increases muscle contraction. At the same time, the concentration of potassium in the cell decreases, which reduces the electrical conduction speed of the heart. This leads to a lower heart rate and better coordination of the heart's action.

What are the benefits of digitalis?

Digitalis is mainly used in dogs with supraventricular arrhythmias, for example atrial fibrillation. This is a condition in which the atria of the heart beat too quickly and irregularly. This can lead to a reduced blood supply to the body and increase the risk of blood clots. Digitalis can bring atrial fibrillation under control, improving the dog's quality and expectancy of life.

Digitalis can also help dogs with systolic pump insufficiency, which is when the heart can no longer eject enough blood. This can lead to heart failure, where fluid builds up in the lungs or abdomen. Digitalis can increase the heart's pumping capacity and thus alleviate the symptoms.

What are the disadvantages of digitalis?

Digitalis has a very narrow therapeutic range, i.e. the difference between an effective and a toxic dose is very small. The dose must therefore be adjusted individually and monitored regularly. Excessive doses can lead to digitalis poisoning, which can be manifested by vomiting, diarrhea, loss of appetite, weakness, tremors, cramps or cardiac arrest.

The effect of digitalis can also be influenced by other factors, for example by the potassium or calcium level in the blood or by other medications. Too low or too high a potassium concentration can increase or decrease the toxicity of digitalis. Other medications can alter the absorption or breakdown of digitalis and thus increase or decrease its effect.

How can I protect my dog from poisoning?

To avoid poisoning with digitalisyou should observe the following points:

  • Only use digitalis as directed by your vet and follow the prescribed dose exactly.
  • Keep digitalis out of your dog's reach and make sure that he does not accidentally ingest tablets or solutions.
  • Avoid your dog coming into contact with foxglove plants growing in gardens or in the wild. All parts of the plant are highly toxic to dogs.
  • Have your dog's blood levels of digitalis, heart function and electrolytes checked regularly to determine the optimal dose and detect side effects.
  • Find out about possible interactions of digitalis with other medications your dog is taking and discuss them with your vet.
  • Monitor your dog for signs of poisoning and seek veterinary advice immediately if you notice any.

Digitalis is an effective ingredient for the treatment of cardiac arrhythmias and pump weakness in dogs. It can significantly improve your dog's quality and expectancy of life when used correctly. However, it also has a high risk of side effects and poisoning, which can be life-threatening. Therefore, you should only use digitalis under veterinary supervision and monitor your dog closely.

The authors assume that a veterinarian should be consulted if an animal is ill and that medication should only be taken after consultation with a doctor or pharmacist. Only an individual examination can lead to a diagnosis and treatment decision.

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