Dog's urine smells unusual.

A few days ago I noticed that my dog's urine smells a bit strong. I can't really describe the smell - it was somewhat musty and more alkaline than I would have expected. I don't know if it's normal because I don't normally smell her pee. We live in a city and I take her out several times each day, so I am always around when she goes, but I can't smell it on the ground when I am standing next to her. On this occasion I ended up smelling it inadvertently because there are some leaves on the ground and she peed on them. One got stuck to her foot, so I pulled it off and some pee got on my hand (TMI, sorry) - so that's how I smelled it.

Anyway, she normally pees four times each day: in the morning, at lunch time, after work, and before bed. Her morning pee is usually the biggest, which has always seemed normal to me, since she hasn't gone since the night before. We also go to the park in the morning and she will "mark" (find a spot where she smells really intently and then sprinkle a very small amount in that spot) once or twice at most.

This morning her regular pee was pretty small. Maybe 1/3 of her normal amount. Then, when we got to the park she "marked" five more times! I didn't how much each time because it was early in the morning and there was dew on the grass.

On the way home from the park she did this one more time, which she never does. A very small sprinkle came out.

She doesn't seem to be in distress at all. She is eating and drinking normally, although perhaps a little bit less (drinking) than usual. It's not particularly noticeable, but she has seemed less thirsty since the weather has gotten cooler. She always has access to clean, fresh water. I leave her for 4-5 hours at a time during the day while I'm at work and she is crated, but has about 2.5 cups of water in the bowl that attaches to her crate. She normally drinks about 1/4 - 1/2 of this while I'm gone, and I change it at lunch when I come home.

Also, her temperature is 100.9, taken with a rectal thermometer our vet gave me after she had surgery over the summer. My understanding is that this is about what it should be.

At lunch time, she peed a normal amount (for her), and it looks normal to me; it's a medium-yellow color and clear (not cloudy). I caught some on a paper towel and it still smells odd to me. I am continuing to keep a close eye on her, but hoping this morning might have just been an anomaly...

Of course, looking things up on the internet becomes quite scary. I am just wondering what these symptoms sound like? Do they require an emergency vet visit? If a vet isn't necessary at the moment, what signs should I look out for that will indicate a more urgent situation? Our next appointment (for annual physical and vaccinations) is one month away, but I will go in sooner if necessary (I just don't want to go in if it's not necessary, since I am sometimes a bit of an alarmist).