4 Signs Your Dog Is Going into Heat
The most frequent symptoms before heat include:
Located just below the anus, your dog’s vulva will turn redder in color and increase in size — often 2 to 3 times its normal size.
A dog entering heat can become more skittish or aggressive around others, including people and animals but especially other dogs.
Increased Licking of the Vaginal Area
While almost all dogs occasionally lick themselves in this area, you may see it much more frequently before they go into heat.
If you notice bloodstains near or around areas where your dog rests, it’s likely your dog is in proestrus and the heat phase is about to begin. Dogs may bleed for up to 10 days during this phase.
4 Signs Your Dog Is in Heat
Once your dog is in heat, you may notice physical and behavioral changes, and changes in how other dogs behave around her. Here are the most frequent signs your dog is in heat.
The amount of blood typically decreases when your dog is in peak heat. Once this occurs, your dog is in the most fertile stage of estrus for about a week to 10 days, until bleeding starts again (although bleeding doesn’t always recur).
When your dog is around other dogs (both male and female), her behavior will be noticeably different. This may include mounting other dogs or letting herself be mounted. If no other dogs are around, your dog might try to mount your legs.
Once she is fully in heat, your dog’s tail will often move or curl to the side. This is known as flagging and lets male dogs know she is ready and available for mating.
If you have male dogs in your household or come across one on a walk, they’ll react differently to your dog in heat. This could include aggression toward other male dogs or increased barking and whining. They may also show much greater interest in your dog’s genital area.
Keep in mind the signs of going into heat and being in heat vary from dog to dog; your dog may not show all (or any) of the above symptoms. If your dog doesn’t show any signs of heat but did show signs of entering heat, she is still likely in heat.
How to tell when a female dog is in heat
If you own an unspayed female, knowing the signs a dog is coming into season can be very important in managing their reproductive cycle. Learning the stages of the cycle will allow you to recognize symptoms such as personality changes, appetite changes, and more as indications a female dog is entering heat, rather than something that requires a visit to the veterinarian. It could also help you prevent having new puppies on your hands when you didnt plan for them and allow you to plan for puppies when you do want them.