Michael Milstein, a spokesman with NOAA Fisheries, said researchers on Wednesday saw the 20-year-old whale known as J35 carrying her dead young off the tip of Washington's Olympic Peninsula.
Officials in the USA are hoping to give J-50 the treatment if she is spotted in the waters off Washington State by dart or by fish offered to her by a pole.
In Canada, where the whales were last seen, the fisheries department does not yet have the legal ability to treat the whale, said marine mammal coordinator Paul Cottrell. "It's fantastic. We're hoping she's going to be OK". "What is visible to us is significant decrease in body condition".
"The big question is, can we craft public policy that can make a difference in the future of the orca, and by doing so make a positive difference in how we live in Puget Sound", Purce said in an interview Monday.
J50 and her brother in 2014.
The calf was the first in three years to be born to the dwindling population of endangered southern resident killer whales, with only 75 members.
Her pod recently drew an worldwide spotlight when another whale, J35, was spotted pushing the body of her dead calf through the water for more than a week.
On Tuesday, the whales were spotted in rough waters off Port Renfrew.
A picture taken by Brian Gisborne of Fisheries and Oceans Canada shows J50 swimming with her mother, J16.
"It was foggy up there for most of the day", Cottrell said. Then the whales disappeared back into the fog. What would be unique is giving the orca medication through live fish, Rowles said.
Teri Rowles of the U.S. National Oceanic and Atmospheric Administration says that if they find J50, they'll assess her health and determine if they will administer antibiotics by pole or by dart, and the whale may receive further treatment of salmon laced with medication. They may drop medicated fish next, if that goes smoothly.
Rowles said injections of antibiotics or sedatives have been given to other free-swimming whales or dolphins that were injured or entangled but it hasn't been done for free-swimming whales in this area.
Orca whales also do not have babies often or in large numbers, and when they do, it is a long process.
The search is on again for J50, the ailing killer whale, in a cross-border effort to save her life.
"We don't know exactly what is wrong with her", Rowles said in a teleconference.
"It's been a number of days since Friday, so it was great to see J50", Cottrell said.
Canadian officials have not received an application to administer antibiotics to the whale in Canadian waters, Cottell said, a procedure NOAA wants to try if J50 is in Washington waters.
The 4-year-old was part of the southern resident "baby boom" that occurred when eleven calves were born between 2014-2016.