My question is more from a long haul flight POV. Does the crew do a mid-flight check etc. What if any animal/pet have a sudden cardiac arrest or some emergency medical situation, will the crew or pilots be alerted for the same?
Are pets/animals in the cargo hold monitored inflight for any sudden medical condition?
$\begingroup$ I don't believe that the crew (flight-deck or cabin) have any access to the cargo hold on most commercial airliners, so if an animal in the hold gets sick, it gets sick. I'm sure that for special, high value animals, say transporting an elephant, that is different, but they usually don't go below decks and travel on an extra baggage charge for the human upstairs. I may sound cold, but I love my dogs as much as a normal person should - we took our 2 dogs JKF-TLV when we moved there. I would have been very sad had something happened to them, but they are just pets... $\endgroup$– FreeManJun 13, 2017 at 11:35
$\begingroup$ As for my personal experience no since my dog was inside of a cage and there was no way to check what was going on inside. $\endgroup$– Federico GentileJun 13, 2017 at 11:36
$\begingroup$ @FreeMan That sounds like an answer to me. $\endgroup$– Dan HulmeJun 13, 2017 at 12:04
$\begingroup$ Thanks, @DanHulme, I don't think anyone's ever said that to me here before! :) Unfortunately, I started with "I believe" for a reason - I'm not really sure about it, thus the coment & not an answer... $\endgroup$– FreeManJun 13, 2017 at 12:06
2$\begingroup$ @FreeMan I guessed as much, but that's not what comments are for. If you post an answer, people can vote to indicate their agreement. If it turns out you're completely wrong and it ends up negatively scored, you can always delete the answer - that also wipes out the reputation change. $\endgroup$– Dan HulmeJun 13, 2017 at 12:08
To the best of my knowledge, no modern (i.e. currently used in regular commercial service in statistically significant numbers) commercial passenger aircraft have access from the main passenger cabin to the cargo hold, so there is no way for the cabin/flight-deck crew to check on the critters below, even if they wanted to. My knowledge, however, is incomplete, as was pointed out in the comments, the 747-100 & -200 (and likely the -400) do have access from the passenger cabin to the forward cargo hold. The flight crew were notified when animals were stowed there, however, a long-serving 747 pilot indicated having never checked in on said animals.
Large and/or high-value animals such as elephants, giraffes, etc. are shipped as cargo via specialist transport companies where arrangements to have them tended in flight are common and accounted for (hat tip to Simon). I doubt you'll see someone pulling up to the departures gate at LGA with an elephant in a crate and wheel him up to the curb-side check-in gate.
As a personal anecdote: When I flew from JFK/KJFK to TLV/LLBG in the mid-80s we took our 2 dogs since we were moving there for a period. We got to walk the dogs on the tarmac just before they were loaded in their crates and put in the hold (747, probably -200) at JFK, but there was no mention of anyone checking on them mid-flight.
Fun fact (for me): We also got to walk the dogs at TLV just prior to our return flight, and that walk ended up taking about an hour as we got to watch them jack up a wheel on a 747 to change a flat tire pre-flight. (Yes, security was much different then. Even in Israel at the height of their occupation of southern Lebanon.)
$\begingroup$ Rare, large and high-value animals are normally freighted by specialist cargo carriers and their carers, vets etc ride along with them. $\endgroup$– SimonJun 13, 2017 at 12:49
$\begingroup$ @Simon - that was my point. Probably wasn't well made. $\endgroup$– FreeManJun 13, 2017 at 13:02
$\begingroup$ Flying Tigers used to transport a lot of animals, including livestock. I was told by fellow employees that after FedEx bought FT the 747s we retained from their fleet still had a foul odor in the cargo compartment. $\endgroup$– TomMcWJun 13, 2017 at 17:43
$\begingroup$ The forward cargo hold of 747-100/200 aircraft is accessible inflight. My guess is that is also true for 747-400 aircraft, but I do not personally know that. However, the access is for maintenance and emergency purposes. You lift a patch of carpet in the aisle just aft of the nose on the main deck, open a hatch, and descend a built-in ladder down into the avionics bay. If you go forward, you'll be at the nose gear emergency extension station. Go aft and take down a canvas barrier, and you're in the forward cargo hold. $\endgroup$– TerryJun 13, 2017 at 18:22
1$\begingroup$ @FreeMan As I remember, we were typically notified (actually the flight engineer was notified) that there were animals on board. I'm certain, though, that we never checked on them in flight in the forward cargo hold. $\endgroup$– TerryJun 14, 2017 at 17:00
The exception to the rule that access to the cargo hold is not available is FedEx (and other freight haulers), who routinely transport zoo animals and other research animals.
In passenger service, generally most cargo holds are not readily accessible. There are some exceptions.
The inaccessibility of the cargo hold is exploited when US agencies transfer classified materials. Couriers will place a container into the hold just prior to the doors closing, and then wait for the aircraft to taxi from the ramp. At the destination, a courier will meet the aircraft at the ramp, and when the cargo doors are opened, the courier extracts the container. Other countries and NATO have similar procedures.