Did you raise the cow or did you purchase it?
Per IRS Publication 225:
Generally, losses of raised draft, breeding, dairy, or sporting animals do not result in deductible casualty or theft losses because you have no basis in the animals. However, you may have a basis in the animal and therefore may be able to claim a deduction if either of the following situations applies to you.
You use inventories to determine your income and you included the animals in your inventory.
You capitalized the expenses associated with the animals under the uniform capitalization rules and therefore have a tax basis in the animals subject to a casualty or theft.
When you include livestock in inventory, its last inventory value is its basis. When you lose an inventoried animal held for draft, breeding, dairy, or sport by casualty or theft during the year, decrease ending inventory by the amount you included in inventory for the animal. You cannot take a separate deduction.
I am afraid the poor little calf had no basis and therefore is not an allowable loss.
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