A sick lion at Franklin Park Zoo will be undergoing surgery on Friday, while the zoo’s veterinary team looks at whether his brother’s blood could be the secret to a treatment.

Kamaia, a 14-year-old lion that has lived at the Boston zoo since 2015, has been experiencing serious health issues. Kamaia is severely anemic, his spleen is greatly enlarged, and he has recently been lethargic and hasn’t been eating as much.

His brother Dinari, also a 14-year-old, on Thursday underwent a procedure to hopefully help his sick brother. The zoo’s veterinary team drew blood from Dinari to see if it’s a match with Kamaia, so they can potentially perform a blood transfusion.

On Friday, the veterinary team is planning to perform exploratory surgery on Kamaia to determine the cause of his serious health issues. If he’s a match with Dinari, a blood transfusion will also be performed.

“We remain very concerned about Kamaia and his ongoing serious health issues,” said Chris Bonar, Zoo New England’s director of Animal Health.

“These procedures are approached with great thought and consideration, and while there is risk and many unknowns as to what we could find, this is the best course of action to try and treat Kamaia,” Bonar added.

Although Kamaia was successfully treated for severe pneumonia earlier this spring, it appeared at the time that he also had some chronic underlying health issues.

An exam last week included the collection of blood, urine, spleen and bone marrow samples, as well as X-rays of his chest and abdomen.

The exam revealed that Kamaia’s spleen is greatly enlarged, which could be the cause of the anemia, but it’s still unclear whether he has something more systemic affecting his health.

“Dinari and Kamaia were born in the same litter, and are an incredibly close, tightly-bonded pair,” said John Linehan, Zoo New England’s president and CEO. “These decisions are being carefully considered with both of their best interests in mind. The Animal Care and veterinary teams have been working extraordinarily hard to care for Kamaia, and I would like to commend them for their dedication, care and professionalism during this challenging time.”