Three weeks ago, my neighbor texted me at 6 AM: "Why is my deck covered in blood? Is Bella okay?" Her eight-month-old retriever had started bleeding overnight, and the poor dog was frantically licking herself while her vulva had puffed up to twice its normal size. Bella's first heat had arrived without warning—which is exactly how it happens for most dog owners.
Maybe you're reading this because you just spotted discharge on your floor. Or your intact female suddenly won't stop whining at night. Perhaps you're trying to figure out whether to spay before or after that first cycle happens. I get it—the canine reproductive system doesn't come with a user manual, and your vet probably gave you a two-minute overview that left you with more questions than answers.
This guide breaks down every stage, symptom, and behavior shift you'll encounter. By the end, you'll know exactly what's normal, what requires a vet visit, and how to keep your sanity (and carpets) intact through multiple cycles.
Physical symptoms show up first. Behavioral weirdness follows a few days later.
Vulvar swelling happens fast—you might not notice anything Monday, then wake up Tuesday to obvious puffiness. The external tissue around your dog's genitals enlarges and changes color from pale pink to deep reddish-purple. Small breeds like Chihuahuas might show minimal swelling you'd miss unless you're specifically checking. My friend's Great Dane? Her vulva tripled in size within...