Male dogs are naturally drawn to females in heat due to their biological response to the pheromones emitted by the female. Keeping a male dog near a female in heat can cause stress for both animals. It is advisable to separate the male from the female and create a relaxing, safe environment for them. If you are raising such a pair together, you can prevent mating. Additionally, both should be neutered to minimize the risk of unintended pregnancies, prevent certain types of cancer, and encourage better behavior.
Steps
Separate the Male Dog from the Female

Keep the male dog away from the female until her heat cycle ends. The only way to ensure the male remains calm is to separate him from the female, as he cannot control his actions when she is nearby. Bring the male indoors or confine him if the female is outside, preventing him from detecting her scent. Avoid walking or allowing the dogs to play together during this time.

Keep the dogs in separate rooms. If you are raising a pair of dogs in the same house, place them in rooms as far apart as possible to prevent the male from detecting the female's scent. Confine them to separate rooms, keep the doors closed, and avoid letting both dogs out at the same time. Ensure no toys or items belonging to the female are in the male's room, as they may carry her scent, which can cause the male to whine, howl, or scratch at the door.

Keep the female indoors and the male outside if your home has limited space. If your house lacks sufficient rooms or space, you can keep the female inside while confining the male to the yard until her heat cycle ends. Ensure the yard is securely fenced to prevent the male from escaping. This option is only suitable in good weather and where local laws permit keeping dogs outdoors. Avoid leaving the female outside during her heat cycle, as she may escape and seek a mate.

Confine the male dog to a crate until the female's heat cycle is over. While you can separate the dogs indoors, you may not always control the male's aggressive behavior toward the female. In such cases, it is best to limit the male's movement by crating him for the duration of the female's heat cycle, typically around three weeks. Prepare for this by acclimating the male to the crate environment beforehand and ensuring he has a spacious crate for comfort.
Create a Relaxing Home Environment

Apply methanol spray to the female's tail to mask her scent. Vick's vapor rub or similar methanol-based sprays are effective in covering the female's heat pheromones. Spray the female several times a day to help calm the male if they share the same living space. Avoid letting the dog lick the spray by distracting her with toys or treats until it dries. Consult your veterinarian before using such products, as they may cause discomfort.

Play with each dog separately during the separation period. Keep both dogs entertained and distracted from the heat cycle by engaging them in play. Provide the female with toys to chew on indoors while taking the male outside for playtime. After spending time with the male, switch to playing with the female indoors while keeping the male in a securely fenced yard. Aim to balance playtime between the two dogs in separate areas to ensure both remain relaxed and calm.

Take the male dog for regular walks. Stick to a consistent walking schedule for the male dog, ensuring he gets adequate exercise based on his breed and size. Frequent walks help the male stay away from the female and burn off excess energy. Avoid walking the female during her heat cycle, as she may attract nearby males. Instead, let her play in a securely fenced yard under supervision to prevent her from chasing passing males.
Neuter the Male Dog

Discuss neutering both dogs with your veterinarian. Neutering both dogs offers numerous benefits. Vets often recommend neutering the male before six months of age, as this reduces mating motivation and lowers testosterone levels. Neutering also decreases the risk of certain diseases and prevents cancer. Spaying the female helps prevent cancer and mammary tumors. Ideally, spay the female before her first heat cycle, though the procedure can also be performed after she begins cycling. Note that neutering does not completely eliminate the male's response to a female in heat, so separation may still be necessary.

Do not feed the dog for 8 hours before surgery. The clinic will provide pre-surgery instructions, typically including fasting for 8 hours before the procedure. Anesthesia can cause nausea, so an empty stomach is essential. However, you may offer small amounts of water. Follow the clinic's guidelines to ensure a smooth surgical process.

Allow the clinic to perform the procedure. The surgery is relatively quick and painless, as the animal will be under anesthesia. The clinic may ask you to drop off your dog in the morning and pick them up in the afternoon.

Assist your dog in recovering after surgery. The clinic may prescribe pain medication if necessary. It is normal for your dog to experience vomiting or loss of appetite for 1-2 days post-surgery. Ensure your dog rests and avoids excessive movement or running for 1-3 days to prevent complications. The male dog's scrotum may swell for a few days, but this will subside after the stitches are removed. If your dog licks the incision, use an Elizabethan collar to prevent this. Contact the clinic immediately if the wound discharges pus or if your dog appears to be in pain. A follow-up visit may be required to remove stitches, though some clinics use dissolvable sutures.
