The following is more analysis/opinion than fact, but still...
From hpcompanion.com, page on The Dream: chapter twenty-nine of Harry Potter and the Goblet of Fire:
Something You May Not Have Noticed
Eagle owls can’t be very common; after all, the Malfoys’ eagle owl
stands out pretty obviously when it brings Malfoy packages from home.
So it’s interesting that Harry’s dream (vision?) starts out with an
eagle owl bringing news to Voldemort. It certainly wouldn’t be
unexpected for the Malfoys to be sending a message to Voldemort (or
loaning him their owl, for that matter), but there is also one other
time that Harry has seen an eagle owl – and it was flying around
Hogwarts just a few weeks ago, before Barty Crouch showed up. Whether
this was the Malfoys’ owl or not doesn’t really matter so much as the
coincidence of noticing an eagle owl around Voldemort, and another one
around Hogwarts. Maybe Harry should have watched a little closer to
see where that eagle owl at Hogwarts went.
From mwwnb-potterthoughts.blogspot.com, posted entitled "Eagle owls and subtlety in writing":
Let's talk about eagle owls for a moment.
I think we all know that the Malfoy family owns an eagle owl. We see
it delivering packages of sweets to Draco early in the series and from
time to time thereafter.
We also know that, in that pivotal vision that harry has in The Goblet
of Fire of Voldemort, Wormtail and Nagini just before the third task,
Harry arrives at the Riddle Manor House riding upon the back of an
But did you notice that J.K. mentions an eagle owl one other time,
earlier in that same novel?
Having grown tired of Ron and Hermione's squabbling over the plight of
house elves, Harry decides to go to the Owlery by himself to send a
package of food to Sirius. After seeing Pigwidgeon and a couple of
school owls off, he stands, looking out over the school grounds, the
Durmstrang ship and the Forbidden Dorest, thinking.
Harry sees Hagrid busily digging a patch of ground outside his home
and he also sees something else: an eagle owl that flies through the
coil of smoke rising from Hagrid's house.
It's a beautifully written, calming scene, like a landscape painting
that draws your eye into the world it depicts.
But it's also a clue. One I had not noticed in all of my previous
readings of this novel.
The eagle owl is bringing messages back and forth between Barty Crouch
Jr. at Hogwarts and Voldemort at the Riddle Manor House. It has to be.
It's the Malfoy eagle and it's being used as part of the plot against
Harry's subconscious mind recognises it as a clue and inserts the
eagle owl into his vision. Instead of a message, the owl brings Harry
When I finally noticed it, I couldn't help but to be impressed, once
again, with Rowling's skills as a writer and the very carefully
thought and planning she put into every novel.
I've always been amazed at how subtly she inserted a bug into every
scene of this book where Rita Skeeter (whom we later discover to be an
animagus) eavesdrops on conversations; I never noticed this lovely and
subtle clue which should have told me, at least given me a clue as to
who was plotting against Harry at Hogwarts.
From wikibooks.org, Muggles' Guide to Harry Potter:
It is interesting that in the dream, an eagle owl carries the message
to Voldemort. Only twice before have eagle owls been seen; one flew
towards the school, looped the Owlery, and flew away while Harry was
lying under a tree by the lake, and in Harry Potter and the
Philosopher's Stone we are told that Malfoy's eagle owl was always
bringing him treats from home. Also, the house in the dream is
described as being atop a hill, and the owl flies through a broken
window. It is unclear if we are meant to draw a connection from these
incidents, but the author may be dropping a subtle hint that the
Malfoy family is tied to Voldemort, although there is no indication
that they know Voldemort's whereabouts.
The eagle owl is a slight
misdirection; while the only eagle owl we know of that belongs to a
Wizarding family is the Malfoys', Lucius does not yet have any
awareness of Voldemort's return. The only Death Eaters who know that
Voldemort is still alive at this point in the story are Barty Crouch
and Wormtail, though Professor Karkaroff and Professor Snape
apparently have their suspicions. This remains true until after
Voldemort summons his Death Eaters, in about another month in our
story. In his present state, Voldemort is relatively weak, and he
wants to avoid revealing his presence by alerting the Death Eaters.
The eagle owl is rare enough that it could be considered a
connection, except that it is apparently intended to mislead.