Mine got hers at about 10 mos though her mom didn't until almost 2 years. I agree with CM though, almost any time. Many dogs are different. Typically they are very like their siblings not nec like mother's or aunties. If you can check with the littermates you'll get a good idea. Some dogs 3 mos and the longest I heard (generally very small or very large breeds) is 3 years though that's rare.
My Golden girl had very little light brown discharge for several weeks. I was so light I was tempted to thing she wasn't in heat. The vet can tell though. Mostly before they become receptive to males the entire vulva area will swell and after that is when you may notice the pinker or bloody looking discharge. This is when she can get preggers. My biggest clue was the swelling since I wipe their vulva area with huggies after peeing I could def feel it.
My girls are so furry back there I find it easier to keep clean with regular wipes after potty. This also made it unnecessary for her to wear heat pants too. I kept her clean and asked her to lay on her bed when napping.
Our vet thought our girl would get her first heat around 7 months but she got it at 6 months on the dot! It worked out nicely though because I kind of wanted her to get her 1st heat before spaying her (it means her growth plates are full grown and "closed)...
It WAS a bit of a hassle though because she got her "period" the weekend before we had to board her for 10 days. The kennel was really good about it - they board breeders dogs - so they kept her in female quarantine. The real hassle was having to wait the 6 weeks AFTER her period stopped before we could go ahead with the surgery..
I saw a female comedian that was joking about female quarantine during menses. She was advocating bringing the women's huts back, but with enhancements. Sure I'd love to go on va-ca once a month, no work, no men (sorry guys but you might also appreciate it), lots of chocolate/alcohol and a masseuse. This might not be so bad esp if medical covered it. LOL A bit off topic but it reminded me. :dogtongue2: It's been a long day today.
LOL I 2nd that motion to bring back the "red tents"... I think men decided to get rid of them when all the women disappeared for a week and they were left to make their own dinner =P just kidding guys!
Just to add... Feeby's heat did not look bloody; it was like she had tracked mud into the house; very watery, brown mud. And yes, very little of it. Even the vet had to chemically test her for being in heat because her vulva did not "drop"