Cholecalciferol Poisoning in Dogs

Cholecalciferol is a form of vitamin D found in rat and mouse poisons as well as multivitamins and vitamin D supplements for humans. But while vitamin D is an important nutrient for dogs, too much cholecalciferol can be toxic to your fur-baby.

When consumed in toxic amounts, cholecalciferol has the potential to cause life-threatening kidney failure. And because it can take 12-36 hours for clinical signs to develop, by which time serious damage may already be done, cholecalciferol poisoning is an emergency.

If you suspect that your pet has ingested any cholecalciferol, seek urgent veterinary treatment. To keep your dog safe, it's also important to make sure they don't have access to any products around the home containing cholecalciferol, including rodenticides and vitamin D supplements.

The symptoms of vitamin D3 (cholecalciferol) poisoning are usually not seen until approximately 12 to 36 hours after consumption. Unfortunately, by the time the symptoms are noticed, the damage may have already been done to the kidneys.

The most common symptoms of cholecalciferol poisoning are:

• Vomiting (sometimes with blood)
• Diarrhea
• Loss of appetite
• Weakness or lethargy
• Weight loss
• Increased thirst and urination
• Abdominal pain
• Bloody feces
• Excessive drooling
• Seizures
• Tremors

If your dog ingests a high dose of cholecalciferol, kidney failure can occur within 24-48 hours. If left untreated, cholecalciferol poisoning can result in death.

Cholecalciferol, also known as vitamin D3, is rapidly absorbed by dogs after being ingested. It poses a higher risk to dogs than vitamin D2 (ergocalciferol), and increases the amount of calcium (hypercalcemia) and phosphorus (hyperphosphatemia) in your dog's blood to abnormally high levels. This can then result in kidney failure, so is a life-threatening emergency that requires urgent treatment.

Rat and mouse poisons that contain cholecalciferol pose the biggest risk of poisoning for dogs. It only takes 0.1mg of vitamin D3 per kilogram of body weight for a dog to display clinical signs of poisoning, and with rat baits typically containing a concentration of 0.075% (0.75 mg/g) cholecalciferol, your dog only needs to consume a relatively small amount to show signs of poisoning.

However, cholecalciferol can also be found in vitamin supplements and psoriasis medications, and can also pose a problem for pets in dog foods that have not been properly formulated.

It's important to seek veterinary attention straight away if you suspect your pet has consumed any cholecalciferol or if they show signs of poisoning. If you know your pet has eaten a specific product, take the packaging with you to help your vet assess how much vitamin D3 your dog has ingested

Your veterinarian will conduct a thorough physical examination, including a urinalysis and blood tests. They'll check your pet's blood cell count, kidney function, and phosphorous and calcium levels to determine the extent of poisoning.

Unfortunately, there is no antidote for cholecalciferol poisoning. But because it can be life-threatening, immediate treatment is required.

If your pet ingested cholecalciferol recently, your veterinarian may induce vomiting and give your pet activated charcoal to help remove the toxins from their system.

Hospitalization and fluid therapy are required in severe cases of poisoning, with additional medications to control calcium and phosphorus levels also potentially needed for some pets. Gastrointestinal antacids will be used to lower your dog’s phosphorous levels, while corticosteroids, diuretics and/or bisphosphonates will be used to reduce calcium levels. 

Phosphate binders and a low-calcium, low-phosphorous diet are also advised.

Serious cases of cholecalciferol poisoning require extensive treatment and can also have long-term effects on your dog's health.

Even once your dog is stable enough to return home, they will need ongoing monitoring of their kidney function as well as their calcium and phosphorus levels. This monitoring phase may continue for several weeks.

The prognosis for cholecalciferol poisoning depends on when treatment is given and how much vitamin D your dog consumed, but prompt treatment is vital to give your dog the best chance of making a full recovery. The prognosis is good for pets that receive decontamination treatment soon after ingesting cholecalciferol, and for those dogs that are treated before hypercalcemia and hyperphosphatemia develop.

Prevention is better than cure, so make sure cholecalciferol-containing products like rodenticides and vitamin supplements are always stored out of reach of your pet.

Cholecalciferol poisoning can be expensive to treat. If you suspect your dog is at risk of cholecalciferol poisoning, start searching for pet insurance today. Wag!’s pet insurance comparison tool lets you compare plans from leading companies like PetPlan and Embrace. Find the “pawfect” plan for your pet in just a few clicks!