Hypercalcemia is defined as abnormally elevated calcium levels in the blood. Of the various types of substances that are poisonous to dogs, there are those that include hypercalcemic agents. Hypercalcemic agents contain vitamin D, medically known as cholecalciferol, which works by raising the calcium content in blood serum to high toxic levels, resulting in cardiac arrhythmias, and then death. Hypercalcemic agents are popular for use in rodent poisons, since rodents do not have resistance to cholecalciferol. In most cases, poisons containing cholecalciferol must be directly consumed by an animal for it to fall ill, however the exception to this is when a dog eats a poisoned rodent.
Dogs that have consumed hypercalcemic poisons typically will not show immediate symptoms. Signs of poisoning may show 18 to 36 hours after the cholecalciferol containing poison was consumed. Left untreated, a dog can die from cholecalciferol poisoning and the resulting hypercalcemia. If the dog does survive, it will have elevated calcium levels for weeks after the poisoning, and this excess of calcium can lead to secondary health problems, like renal failure.
- Increased thirst
- Frequent urination
- Generalized weakness
- Muscle spasms
- Elevated blood serum calcium
The main cause of hypercalcemic poisoning is from the ingestion of rodent poison. If you suspect that your dog has come into contact with rat or mouse poison, and you are seeing some of the symptoms listed above, you will need to bring your dog to a veterinarian before your pet's health becomes critical.
Keep in mind that outdoor dogs (or dogs that go outside frequently) are at risk of rodent poisoning. It might be in a neighbor's yard, in a trash bag, or in an alleyway. Dogs that engage in chasing and killing rodents may also be susceptible to this type of poisoning. Even if you do not live in an area where rats or mice are a concern, rodent poison may be used for other common suburban pests like raccoons, opossums, or squirrels.
Your veterinarian will perform a thorough physical exam on your dog, taking into account your pet's background medical history, onset of symptoms, and possible incidents that precipitated this condition. A complete blood profile will be conducted, including a chemical blood profile, and a complete blood count. Your veterinarian will conduct a blood test to check your dog's calcium levels and presence of poison. If possible, you should take a sample of your pet's vomit with you to the veterinarian, so that it can also be examined for the presence of poison. If you have the poison that your pet ingested, you should take that to your doctor as well.
For immediate first aid, try to induce vomiting with a simple hydrogen peroxide solution of one teaspoon per five pounds of body weight -- with no more than three teaspoons given at once. This method should only be used if the toxin has been ingested in the previous two hours, and should only be given three times, spaced apart at 10-minute intervals. If your dog has not vomited after the third dose, do not use it, or anything further, to try to induce vomiting. Do not use anything stronger than hydrogen peroxide without your veterinarian's assent, and do not induce vomiting unless you are absolutely sure of what your dog has ingested, since some toxins can do more harm coming back through the esophagus than they do going down. In addition, do not try to force more vomiting if you dog has already vomited.
One of the side effects of hypercalcemic poisoning is dehydration, which can lead to organ failure and seizures. You will need to make sure that your dog is getting plenty of water, and is able to retain the water it is taking in. Increased salt can help to increase or maintain body fluid, as well as induce excretion by the kidney. Adding a small amount of salt to the water you are giving to your pet will encourage fluid retention. Your veterinarian will work on correcting your dog's body fluids, electrolyte imbalances, and lowering the calcium levels using diuretics, prednisone, oral phosphorus binders, and a low calcium diet.
Living and Management
Dogs that have survived hypercalcemic agent poisoning may succumb to some long term side effects due to the high level of calcium in the blood and in the body's organs. The kidneys, for instance, are commonly damaged as a result of hypercalcemia.
The best prevention is to keep rodent poisons placed in areas that are not accessible to your dog, and to supervise your pet so that it does not get a hold of a rodent that may have ingested poison containing a hypercalcemic agent.