Pets with mast cell tumors can also have complications like stomach problems from the overproduction of histamine and excessive bleeding from the release of heparin. Mast cell tumors occur in both dogs and cats. Although some are benign, most of these tumors are malignant.
Generally, hard-boiled eggs can last a week in the refrigerator. Even with its natural (but easily cracked) calcium-carbonate container, a hard-cooked egg is a perishable food, so it shouldn't be kept at room temperature for more than two hours.
Of course, questions of how long do hard boiled eggs last in the fridge and how long are boiled eggs good for depend upon proper storage.