Crate size and airfare from Wash Dulles to LHR?

We have 2  20 lb shitz tzus to take to the UK this summer.  Does anyone know the correct size crates we would get for them and the approx. cost to ship from IAD (Wash Dulles) to Heathrow on Virgin or BA?  Also which airline is better with pets.

Also we need to get to Glasgow and was thinking the best thing to do would be my husband could fly with the dogs, rent a car and drive to Glasgow, rather than paying to have them fly.

You'll need to measure your dogs to be sure--they need at least 3" from the highest point on their heads (this would probably be where the ear folds for a shitz tzu) to the top of the crate.  I suspect that they will probably need an intermediate size crate, but measure to be sure.  My sense is that the airlines are quite conservative about this, so if they are barely going to fit into one size crate (according to the 3" guidelines), go up a size.  Lots of people have had to buy crates at the airport because they didn't hadn't bought big enough to begin with.  My cats look like they are swimming in theirs, but the next size down wasn't quite big enough.

Shitz tzus are a flat nosed breed, right?  If so, you may find it difficult to travel with them during the summer.  Many airlines have temperature restrictions during the summer, and they are even stronger with flat nosed breeds.  They will usually have a list of restricted breeds on the airline's website.  Even if they are not among the restricted breeds, it may be difficult to find an airline that will fly animals out of DC in the summer.  Continental is the only company I know of that doesn't have summer heat restrictions (I'm flying from Dallas in July, so it's a big issue for me!).  If you find that Virgin and BA can't do what you need, you might want to try Continental.

You may also want to consider flying into Manchester instead, if you need to get to Glasgow.  It's closer, and the import fees are less than Heathrow.

It was my understanding that from DC we could not fly to Manchester - that our only choices are Virgin and British Airlines into Heathrow.  I think Chicago is the only city that was on my list that flies to Manchester.  To fly Conteniental we would have to fly from Newark.
The flights are usually in the evening - would this make a difference in flying in the summer?

You'll have to call each airline or look at their website to find out what their summer policies are.  If I were you, I would probably call--that way you can make sure that the policies you are discussing apply to shih tsus as well.  Evening flights will probably make a difference, but I believe the temperature restrictions are a matter of federal regulation (maybe it can't be above 80 or 85?  I don't remember exactly), so most airlines won't fly animals when it's that hot.  I imagine it would be hard to count on temperatures in DC in the summer, even in the evening.  But, again, it's worth calling both of the airlines you are interested in and discussing it with them directly.

You can only fly direct on those planes, but you could pick up connecting flights to Manchester from DC.  I wouldn't blame you for wanting to fly direct, but it might be worth keeping in mind.  Heathrow to Glasgow is a heck of a drive!

I would definitely call the airlines directly.  No information you get on this board is a worthy substitute for first-hand information from the airlines, because their policies and prices can change on a whim.  This is particularly true for snub-nosed breeds, which most airlines have extra requirements to ensure their health and safety.

Also, I would consider making the drive on the US side of the Atlantic.   I lived in DC and drove to Newark to fly Continental direct to Manchester. We still had a couple of hour drive from the airport to Harrogate, but frankly I think it was mentally much less taxing to know I was at least within a couple hours drive from my final destination after a long, sleepless flight than an entire 'nother day's worth of travel.  The drive from DC to Newark is super-easy (provided that traffic isn't horrific) - I95 - NJ Turnpike ex 13 - about 4 hours (traffic-dependent).

FYI - I called the airlines yesterday.  Neither BA nor Virgin have summer restrictions from Wash Dulles.  But Virgin does not fly Shitz Tzus or other snout nose breeds.  BA does and they were very helpful on the phone.  The price they quoted for 2 medium sized crates was $1268 for both dogs.  But after measuring them I think they need an intermediate size crate because they are big shitz tzus.

Also if we drove to Newark, we would still need to rent a car and drive from Manchester to Glasgow which is 3 1/2 hours away.   It is 6 hours from LHR to Glasgow.  We also would need to rent a car to get to Newark because we will be moving and will have sold our car.  So for us it probably make sense just to drive from LHR.  We will probably stay in a hotel one night and rest, then drive up.