A: Classical Hanafi texts state that an animal that has 1/3rd or more of the tail cut off, cannot be considered for Qurbani as this is such a defect that makes the animal ineligible for Qurbani.
However, some Ulama do not consider the tail that has been removed for medical and health reasons to be a defect in the animal and hence, such an animal shall qualify for Qurbani.
One should make a concerted effort to make Qurbani of an animal that conforms to the specified requirements, especially when these are easily available. If there are no sheep with tails available in a certain place, then goats could be acquired or one could purchase a share in a cow or bull.
Darul Ihsan Fatwa Dept.