When is the best time to breed a dog in heat? Here’s the Answer

Physical and Behavioral Changes With LH Surges

Prior to the LH surge, the bitch will have considerable edema, or swelling, and dark red bloody discharge. As estrogen drops and progesterone begins to rise at the start of the LH surge, the edema will go out of the vulva and vagina. You may observe softening of the skin around the vulva and a change in the discharge from a dark bloody red to a more serum straw color secretion. This may not be obvious in every bitch. If you are taking your bitch to a veterinarian for ovulation timing they will visually see a change from edematous to crenulation on vaginoscopy.

The day of the LH surge is often when there is a dramatic change in flagging behavior. For example, when a bitch wasn’t flagging in the evening but is in the morning. This abrupt change is often on the day of the LH surge (Day 0) or right around it. This is when fellow house mates will start mounting, but the male is not that interested yet. Male dogs will usually intensify their interest and go off feed and cry for the female on Days 4, 5, 6, and post LH surge.

When intact females are the only dogs in a home, you may notice that the bitch starts to walk around and whine a little, or the bitch may flag when someone bumps in to her. This is something that is very useful to record on bitches’ cycles that occurs prior to breeding. Keep a record of first day of heat, the day the bitch starts dramatically standing, and days where males are crying for them. It’s also good to record the first day where the female goes out or abruptly loses interest in breeding.

Generally when a bitch first starts standing she will be ready to breed starting two to three days later. When males are crying, off feed, and crazy for a female, the bitch is likely in her optimum fertile period and ready to breed then.

When breeding highly fertile males or where semen count and quality is not an issue, progesterone blood levels and vaginoscopy can be successfully used to estimate when the LH surge occurred. Levels are typically in the baseline 20 nanograms per milliliter (although levels can be 40 nanograms per milliliter or higher) during the optimum fertile period. There is variability from one diagnostic lab to another so important to know how your local diagnostic lab tends to run.

The dramatic change in Progesterone levels during the breeding period renders it an excellent tool for ovulation timing. However, some bitches who haven’t read the book and can vary considerably from the expected levels. A veterinarian experienced with ovulation timing (OVT) can help identify these bitches.

When using frozen semen or semen of poor quality, blood samples should be drawn daily and tested for LH. Typically progesterone levels are run every other day and serum saved from the days in between. Once the progesterone rise is documented, the appropriately saved samples can be tested for LH. Progesterone levels need to be followed until ovulation is clearly confirmed (progesterone 5-to-8 nanograms per milliliter).

Signs That a Female Dog Is Ready To Mate

Signs to watch for that will show you she is ready include:

Bloody Discharge — This is the most common sign that female dogs will show when they are in season. The blood tends to be bright red and will start to fade in color and thin out until the end of the heat stage.

Male Interest — It is said that male dogs can “sense” when a female is in heat by her scent within several miles and will naturally gravitate towards the female and mount her when he gets the opportunity. You will notice this happens a lot during this time. You can also assist in the process by putting both female and male dogs together to see how they respond to one another.

Tail Flagging — A dog who is ready to mate will show interest in other males by raising her tail to allow penetration.

Swollen Nipples — Check your dog’s nipples and watch to see when they begin to swell which is a pretty good sign she is ripe.

Increased Urination — A bitch in heat will urinate more often and sometimes in smaller quantities.

Mood Change — A dog in heat will become moodier by either being more temperamental than usual or she may even show signs of neediness.

Keep in mind that not all dogs will show all signs when she is ready, so to be sure you need to be alert and pay attention to your dog’s behavior. Dogs can also go into “silent” heat in which she will show no signs at all which can often confuse an inexperienced breeder.

Mating Age For Male Dogs:

A male dog is mature for mating possibly from 4 months onwards but generally, it is considered at about 6 months.

When to breed your dog when they are in heat