Dogs diagnosed with hyperkalemia have too much potassium in their blood. It almost always affects canines already suffering from kidney disease. Occasionally, it results from urinary tract blockage or bladder rupture. Because high potassium levels affect the heart, hyperkalemia is a veterinary emergency.
Hyperkalemia in canines is primarily caused by not excreting sufficient urine. Properly functioning kidneys help a dog eliminate potassium. Once the dog stops peeing enough and not getting rid of excess potassium through the urine, hyperkalemia can develop within two days. Although it's also possible that a dog can develop hyperkalemia from potassium over-supplementation, that's a rare cause of the disease.
Dogs suffering from hyperkalemia might experience off-and-on gastrointestinal issues such as vomiting and diarrhea. More obvious symptoms include lethargy and outright collapse. The dog's heart rate slows considerably because excess potassium disrupts his blood circulation. A dog can show signs of paralysis, but his limbs remain flexible, not stiff, even if the animal can't move them. A dog might have difficulty urinating, or produce very little pee.
Your vet will perform an electrocardiographic test, or ECG, on your dog to determine the heart rate. She'll also take your dog's complete health history, but if your pet's already under treatment for kidney disease, your vet will have much of that information. She'll take urine and blood samples. If your dog strains to pee, your vet might conduct an ultrasound to determine if there's an obstruction in his urinary tract.
Your vet will lower the amount of potassium in your dog's bloodstream via intravenous saline solution. In severe cases, the potassium might be removed from the bloodstream through dialysis. Once the crisis is over, you'll have to bring your dog to the vet regularly to have his blood potassium levels checked. If your dog is under treatment for kidney disease, your vet has probably already prescribed a prescription diet for him. If hyperkalemia becomes an issue, your vet might prescribe a canine kidney diet with even less potassium.
If your dog goes to the vet and his blood work returns from the lab with an off-the-charts level of potassium, don't panic, especially if your dog appears fine. The test results could stem from pseudohyperkalemia, a condition occurring when excess potassium leaks from the cells after blood drawing. It's a common occurrence in akitas and shar-peis. Dogs actually suffering from hyperkalemia usually appear sick.