Jerry was born in Santa Isabel Island, a part of the Solomon Islands archipelago. Jerry's owner was Mr. Haggin, who worked as a plantation guard and used Jerry to chase black slaves. Higgin gave Jerry to Mr. Van Horn, Captain of ship Arangi, under condition to return the dog if something bad happens. The ship was engaged in delivering so-called "reverse" slaves who worked for three years on a plantation. During a stop on Malaita island, Arangi was attacked by the natives, who killed the captain and skipper. Jerry was kicked from the ship, which was looted and burned. A native boy found Jerry in the sea and delivered the dog on the shore. Later, Jerry was brought to a village, where tribe chief Bashto decided to use Jerry for improving the breed of local dogs. Jerry received a taboo status and began to live among the tribemen.
Jerry led a fairly quiet life until local sorcerer Agno decided to use the dog for a sacrifice. To overcome its taboo status, Agno arranged Jerry to attack a holy bird megapoda, which also had a taboo status. Jerry stole the bird eggs, which were kept for chief Bashta. Jerry was spotted while killing the fourth bird. The bird's taboo status was higher than that of Jerry; therefore, the dog could be sacrificed. However, old blindman Nalasu bought Jerry for a pig to protect himself against an expected vendetta.
Later, the village was destroyed by Brits as a part of punitive operation to retaliate for the loss of Arangi. Jerry escaped and hid in the jungle. Having stayed there for a long time, Jerry began to look for people. Out in the beach, the dog saw a distant ship and plunged into the sea, thinking it is Arangi and hoping to see his beloved Captain Van Horn. The ship was the yacht Ariel traveling around the world. People on board noticed the dog and saved it.
One of the crewmen recognized the dog and announced that it is a dog of Mr. Haggin form Santa Isabel Island. Later, the yacht arrived at Tulagi harbor, where a commissioner who new Mr. Haggin sent him a message. Mr. Haggin sailed to the island with dog Michael, who was the brother of Jerry. Tho brothersâJerry and Michaelâmet each other just to be separated ten days later. Jerry stayed on the yacht Ariel with its owner, Villa, while Michael stayed on the island. They met each other once again several years later in California.

Question: Why did the old blind man Nalasu buy Jerry?
Answer: He bought Jerry to protect himself against an unknown vendetta.
Alternative answer: to protect himself