Managing you dog when they come into season (some of this is useful for heatwaves too!)

Dalmatian on a lead on a quiet road

What is a season (Oestrus Cycle)?

When a female dog (bitch) comes into season, she is going through her oestrus cycle — the period during which she is fertile and capable of becoming pregnant. Most bitches experience their first season between six and twelve months of age, though larger breeds may not cycle until they are eighteen months or older. After the first season, most dogs cycle roughly every six to eight months, though this varies by individual and breed.

A full cycle lasts approximately three weeks (around 21 days), though some dogs may run slightly shorter or longer. Understanding what is happening physically and behaviourally during this time is essential for keeping your dog safe and comfortable.

The four stages of the oestrus cycle (this was drummed into me as a veterinary nurse)

1. Proestrus (Days 1–9) Bleeding starts

This is the beginning of the season. The vulva swells noticeably and there will be a bloody discharge, which can range from bright red to a darker, brownish colour. During this phase, your dog may attract male dogs but will typically not be receptive to mating — she may snap or sit down to refuse a male's advances. Behavioural changes often begin here.

2. Oestrus (Days 10–14) Mating behaviour alert

This is the fertile window — the most critical phase for preventing unwanted pregnancy. The discharge usually lightens to a pale pink or straw colour. Your bitch will now be receptive to males and may actively seek them out. A male can smell a bitch in oestrus from up to 3 miles away. This is the phase requiring the strictest management.

3. Dioestrus (Days 15–21+) Attraction reduces

Fertility declines and she will begin to rebuff male interest again. The discharge fades and the vulva returns toward its normal size. However, do not relax precautions too early — some dogs remain attractive to males beyond day 21.

4. Anoestrus Back to normal

The resting phase between cycles. No sexual activity, no discharge. The body prepares for the next season.

Signs your dog is coming into season

Watch for these early indicators:

•        Swollen vulva — often the first physical sign, even before discharge begins

•        Licking at the vulva — more frequently than usual

•        Bloody or pink discharge — on bedding, the floor, or her coat

•        Increased urination — she may mark more frequently on walks, depositing pheromones to attract males

•        Clinginess or restlessness — some dogs become unusually affectionate

•        Tail flagging — holding the tail to one side when touched near the hindquarters (a sign of oestrus/receptivity)

•        Mounting behaviour — she may mount other dogs or objects

•        Loss of appetite — in some individuals

•        Nervousness or irritability — some bitches become snappy or easily startled

Keep a diary of your dog's seasons, noting start dates and duration. This helps you anticipate future cycles and manage them proactively.

How behaviour may change

Every dog is different, but common behavioural shifts during a season include:

•        Increased scent marking — on walks, even in dogs that don't normally mark

•        Heightened prey drive or reactivity — in some individuals

•        Reduced focus and concentration — she may seem distracted during training

•        Increased affection or velcro behaviour — wanting to be close to you at all times

•        Restlessness and unsettled sleep — especially around the peak fertile days

•        Aggression toward other female dogs — hormonal tension can increase conflict between bitches

•        Attempting to escape — a bitch in full oestrus may be motivated to roam and find a mate; dogs that have never shown escape behaviour before may suddenly try to dig under fences or bolt through gates

•        Vocalisation — some bitches whine, howl, or cry more than usual

It is important to remember that these behaviours are hormonally driven. Punishing your dog for them is ineffective and unfair. Instead, manage the environment and redirect her attention.

Keeping her safe: Practical management

At Home

•        Check fencing thoroughly — for any gaps, weak spots, or areas she could dig under. A motivated bitch in season is an escape artist, especially for any entire dogs who are neighbours

•        Double-gate entry points — use an airlock system so there is always a second barrier between her and the outside

•        Keep male dogs separated completely — if you have an entire male in the household. Even brothers and fathers will attempt to mate. They must be fully separated, not just in different rooms.

•        Use washable dog nappies/diapers — to manage discharge indoors if heavy. Change them regularly to keep her comfortable.

•        Wash her hindquarters — gently with warm water as needed to prevent skin irritation from discharge.

On Walks - if you really need to during peak attraction!

•        Walk her only on lead — for the entirety of the season, even in areas where she normally has reliable recall. Recall can break down entirely during a season.

•        Avoid peak dog-walking times — early mornings and late evenings when fewer dogs are out can reduce the chance of encounters.

•        Vary your routes — unfamiliar areas have less of her scent deposited, reducing the chances of males tracking her.

•        Do not visit dog parks, dog-friendly cafes, or group training classes — during this period.

•        Consider driving her to the start of a walk — rather than walking from home, to reduce the trail of scent deposited near your house.

•        Be prepared to turn back early — if you encounter an entire male on lead.

Training during a season, what is safe and what to adjust

Many owners worry that they should stop all training during a season. In truth, gentle, low-pressure training is not only safe but beneficial — it provides mental stimulation, maintains your bond, and helps keep her calm and focused. The key is adjusting your expectations and methods.

What to scale back

•        High-intensity exercise — avoid long runs, agility, flyball, or vigorous physical activity, particularly in the first two weeks.

•        Off-lead work — recall, distance work, or any training that relies on her being off lead is not recommended.

•        Group classes — she should not attend group classes or sessions with other dogs present.

•        Complex new learning — her concentration will be reduced during peak oestrus; trying to teach new or complex behaviours is likely to be frustrating for you both.

What is safe and recommended

•        Short, frequent, positive reinforcement-based training sessions — five to ten minutes is ideal; her attention span may be shorter than usual.

•        Foundation skills and known behaviours — practise sits, downs, settle, look-at-me, name recognition, and hand targeting.

•        Trick training — light, fun tricks such as spin, paw, roll over, or bow are low-stress and rewarding.

•        Nose work and scent games indoors — scatter feeding, puzzle games, or snuffle mats give her brain a workout without physical strain.

•        Calm loose-lead walking — in quiet, low-traffic areas to gently reinforce lead manners.

•        Settle and relaxation training — teaching or reinforcing a calm 'settle' on a mat is ideal, encouraging the very behaviour you want her to default to.

Training mindset during a season

Hormones affect the brain, not just the body. If your dog struggles to focus or seems uninterested in food rewards — which can happen during peak oestrus — do not push through. End the session on a positive note with something easy, and try again later. This is not the time to expect peak performance. It is a time to maintain your relationship, keep her mind occupied, and ride out the cycle together.

Enrichment ideas that are safe during a season

Mental enrichment is your best friend during a season. It tires a dog out without the risks of off-lead exercise and helps manage restlessness.

•        Snuffle mats and scatter feeding — hide kibble in a snuffle mat indoors or in the grass of a secure garden

•        Licki mats and stuffed Kongs — frozen food stuffing extends the activity and promotes calm licking behaviour

•        Food puzzles and interactive feeders — Nina Ottosson-style puzzle toys vary in difficulty and keep her engaged

•        Scented Bubbles — Peanut or Chicken flavour bubbles can be great fun

•        Hide and seek — hide treats or a favourite toy around the house and encourage her to find them

•        Chewing — Bully sticks, Yak Milk chews, other forms of dog jerky or rubber chews promote calm and are mentally tiring

•        Cardboard box foraging — fill a box with scrunched paper and hidden treats for her to forage through

•        Trick training indoors — as described above, short trick sessions count as enrichment

•        Calm grooming sessions — many dogs find gentle brushing soothing; this also doubles as an opportunity to check her physical condition

When to call your vet

Speak to your vet if you notice:

•        Excessive or unusually coloured discharge — dark green, black, or foul-smelling discharge could indicate infection

•        Lethargy, vomiting, or increased thirst and urination — these can be signs of pyometra (a serious uterine infection) which can develop after a season

•        A season that seems unusually prolonged — more than four weeks

•        No season by 18–24 months of age — in an entire bitch

Any concerns about accidental mating — if your dog has been tied or you suspect a mating has occurred, contact your vet within 24–48 hours.

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Signs of a phantom (false) pregnancy (4 to 9 weeks post season approx) — nesting, milk production, carrying toys, increase reactive or repellent behaviour, guarding — which may require veterinary advice and treatment. Likely to reoccur after one event.

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A note on spaying

If you do not intend to breed from your dog, spaying is worth discussing with your vet. Current guidance in the UK recommends waiting until after the first season for most breeds, and longer for larger and giant breeds, to allow hormonal development to complete. I prefer waiting until your dog is closer to 2 years old to ensure sufficient growth and personality has had a chance to develop. There may be reasons to spay your dog earlier and this is worth discussing with your vet, and if behavioural concerns are present, then working with a behaviourist is helpful.