If U have bloody noses
from the dry heat, get a humidifier
& run it - the best use a UV-light to sterilize the incoming H2O, so U need not use distilled water, but can use tap-water.
It's also best to get one that uses ultrasonic waves to create the mist / break-up the water column to disperse it. // the old-fashioned cheapies
use an expanded-sheet-paper filter to wick the water upward, & a noisy fan to push moisture out... the "filter" isn't filtering anything, it is simply a wick to suck water up from the well at the bottom, fed by a spring-loaded valve on the bottom of the tank.
The "filter" is a great surface to deposit minerals & grow bacteria - I would not advise buying this type, get a good digital hygrometer / UV-light / ultrasonic one, it will last for years.
Also, Amazon & other retailers sell warranty coverage - mine can be replaced if it dies within the 1st 3 years, cost me an extra $6.
45% humidity is a good minimum, 50% is preferable, & 55% is fine -
a 2 to 4-gallon tank will humidify a fair-sized apt, but for a house, U need one unit per floor, as dryness will vary from floor to floor.
my client's kitchen runs around 35% to 40% humidity during the day, when the sun does some passive heating, but at night it falls to 30% & under.
The basement, where the FURNACE is located, actually has the driest air; the bedrooms on the ground floor run 40 to 45%, which isn't terrible, but isn't great, either.
Hope the dog has seen a vet, & is doing better.
Did U get a diagnosis? // of the cough?