Breeding dogs is a rewarding experience. From simple genetics to successful whelping, here we will tell you all you need to know to give yourself the best chance of ending up with a happy, healthy litter of puppies. Even if you are not planning for puppies, it helps to be aware of all the stages in your bitch’s reproductive cycle, so that you can understand her behavior, and the changes taking place in her body. Mating pregnancy and whelping need careful management. Avoiding unwanted pregnancies can be a full-time job too. Dogs in the wild mate naturally at their first “heat”, and, if unchecked, domestic dogs will readily do likewise. If your bitch is expecting a litter, keep your vet informed of her progress. He will give you all the help and support he can.

Introduction to Genetics
The basic unit of all life is the cell. This is true of everything from the smallest single-celled bacteria to man himself. A dog is made up of same “building blocks”. The cells in each dog are unique to that individual.

Apart from the sex cells, all cells in an animal contain the same set of instructions since they are all produced from the same fertilized egg. These instructions enable the cells to develop in different but co-ordinated ways into a whole animal.

Inside each cell is the “cytoplasm” – a complex mixture of chemical structures. At it heart is the “nerve center” or nucleus, which contains the “blueprint” for the design of the dog.

Genes and Chromosomes
The information needed to carry out this incredibly complex organization is carried by structures in the nucleus called chromosomes. Chromosomes can be thought of as strings of different colored breeds.

Broadly speaking, the various breeds are represented by genes. Genes work singly or in concert to control all aspects of structure and function of the body, whether it be hair and eye color, bone growth or the efficiency of blood clotting. Unfortunately, genes are responsible for many canine diseases and disorders, too. There are genes controlling everything that makes a dog a dog.

A dog has 78 chromosomes which fall into 39 pairs, representing the “blueprint” for the dog. These can divide to produce identical copies of themselves.

Sex Chromosomes
Although chromosomes are paired, one pair in each dog is not necessarily an identical pair. These are the chromosomes which determine the sex of the animal. The female has a pair of identical X chromosomes (XX); the male has one X and one Y chromosome (XY). When the egg and sperm cells (the sex cells) meet at conception they combine to form a full set of 78 chromosomes. It is the male’s contribution (the sperm) which governs the sex of the offspring, depending on whether an X or Y sperm reaches the egg first.

Inheritance of Parental Characters
At the moment of conception, the new cell formed receives a copy of one chromosome from each of its parents’ pair. Therefore there are two genes present for each character. These are usually called “alleles’. One comes from each parent, and they aren’t necessarily the same. There may be a series of different alleles relating to a character such as coat colour. An allele which can act on the appearance of a dog when present singly in “dominant”. If both allele needs to be the same before they can express themselves, the allele is “recessive”.

The unique gene pattern that represents an animal is called its “genotype”; its final appearance – the result of the genotype’s effect – is called the “phenotype”.

The Reproductive System
Unlike a male cat, the male dog is easily distinguished from the female by the penis, hanging within the prepuce along the underside of the abdomen. The two testes are also obvious, located in the scrotum which hangs between and behind the hind legs. The sexual organs of the bitch are located inside the body.

The Male Dog
The testes consist of a mass of coiled tubes which produce sperm (male reproductive cells). This is stored in a sac called the epididymis. The production of the sperm begins at puberty and continues throughout the dog’s life, although output is reduced through age or disease.

The common outlet for both urine from the bladder and semen from the testes and associated glands is the urethra. This leads out of the bladder and through the penis.

Sexual Development of the Dog
The testes develop inside the unborn puppy, and are attached to the scrotum by a ligament. As the new born puppy grows, the ligament contracts, causing the testes to descend through the inguinal canal into the scrotum. They should be fully descended by about two weeks of age. At this stage, they can often be felt. As the puppy grows, fat in the scrotum may make them difficult to feel again until about four months of age. It is important that a dog has two descended testes. If not, it is “crypt orchid”.

Deciding to Breed from your Bitch
Letting your bitch have a litter of puppies is rewarding and fun, but should never be undertaken without serious thought. You probably won’t profit financially, particularly when you take into account the work and inconvenience involved plus the expense of feeding and vet’s fees.

Far too many unwanted puppies are produced by irresponsible owners. Make sure you’ll be able to sell yours at the going rate before taking your bitch to stud. It is morally wrong to bank on selling puppies cheap to get rid of them easily. You’ll just be increasing the amount of unwanted dogs that jam the doors of animal shelters daily.

Breeding from poor stock does not any good. The pregnancy may be so poor that they require euthanasia due to congenital disease. People argue that using poorer stock maintains variation in a breed and a wide “gene pool’, but it only produces more unwanted pets.

When to Breed from your Bitch
Pregnancy and birth causes a major metabolic change in a bitch and she should be physically fully mature first. A young bitch’s bones stop growing at between ten or 12 months of age and in larger breeds, a general filling out and “muscling up” of the body occurs after this.

It is best to let a bitch have one normal “heat” before breeding from her – there’s a better chance of a good sized, healthy litter. Female dogs in the wild mate naturally at their first “heat”. They usually become pregnant, often resulting in small litters which die because the bitch wasn’t in the top physical condition to rear them.

Dealing with Accidents
Dogs mate readily by instinct and accidental mating (misalliance) is fairly common, especially if a bitch’s owners don’t supervise her properly during her heat. Bitches can be given a canine version of the pill or injection to stop them cycling. If you don’t plan to breed from your bitch, most vets advise spaying rather than long-term medication.

If you know your bitch has mated and you don’t want puppies, she can be injected within the first 24 to 48 hours after mating (95 percent certain to prevent conception). However, there is a risk of side effects and your vet will warn you about these. If you want to breed from her again, it may be best to let her have this litter, even if the puppies are cross-bred.

Some breeders say that ten days after the beginning of the discharge is the best time for mating; others prefer 12 days. A good compromise is a double mating – either on the 10th and 13th days.

If your bitch shows few external signs of her “heat”, the vet can take a series of vaginal smears to assess the stage of her cycle and help you judge the correct time for mating. This is expensive and dog owners normally resort to it after a few failed mating which they may have considered due to bad timing.

The Stud Dog
Most stud dogs are “initiated” at around ten months old, preferably using an experienced bitch. Using an untried dog (even a show-dog) on a maiden bitch can be tricky and upset both dogs, so if this is your bitch’s first time, make sure the stud dog is sufficiently experienced.

You won’t see much change in your bitch for at least four weeks after mating. In fact, a few bitches show no signs of pregnancy at all until their puppies are born!

Pregnancy lasts an average of 63 days, although puppies may be born alive up to seven days either side of this. So from the date of mating, you can work out when the litter is due.

It is usually possible for a vet to diagnose pregnancy at around 24-32 days. The growing, fluid-filled amniotic sacs which surround the puppies can be felt as small, tense spheres in the uterus. This may be a waste of time with large, fat or nervous bitches. If there are few fetuses, the result will probably be an educated guess. After 49 days, bitches can be X-rayed to see how many puppies are present.

Care of a Pregnant Bitch
If it is the first whelping for both you and the bitch, consult the vet three or four weeks after mating. At this stage, he can check the bitch, confirm pregnancy if possible, and give you advice on care and feeding.

When the bitch is five to six weeks pregnant she needs more food – from one-third to a half extra. Meals should be small and frequent because the growing fetuses occupy a good deal of abdominal space and larger meals will fill her up too quickly.

The theory that “milk makes milk” is misguided. To promote lactation the bitch needs good quality protein. Some milk is valuable, but she requires cheese, eggs and meat too, as well as prescribed doses of a vitamin mineral supplement.

Green Discharge
Some bitches have a persistent light green mucus discharge throughout pregnancy – a substance produced in the placenta. This is no problem and often decreases in the last two weeks. You’ll see more of it during whelping.

Pregnant bitches need exercise but don’t encourage too much rough-and-tumble, particularly after the four week stage. In the later stages, continue with regular short walks, but let her do things at her own pace without becoming overtired.

Preparing for Whelping
It is easier to new born puppies to find their way to a nipple if you trim the hair round the mammary glands of long-haired bitches. Similarly, to avoid a long-haired bitch becoming too messy during the whelping, trim the hair round the vulva carefully with the scissors.

Once a bitch is a day overdue, consult the vet. If your bitch had multiple mating, tell him if nothing has happened by the last due date.

Anticipating a Difficult Bitch
It is important to involve the vet early with a potentially difficult birth. Try to anticipate the problem before it actually happens.

If a Caesarean is necessary, it is much better for your bitch to have it during the day than in the night. In the daytime there’ll be plenty of vet staff around to revive the puppies. Very few practices have separate staff for night duties. The vet you see at night will often have worked the previous day and be working the following day too. It makes sense to see him when he is at his most alert and when maximum assistance is available. A difficult birth is a veterinary emergency, requiring at least two, and often several people to assist. In a multi-vet practice, only one vet will be on duty each night, so you may not see the one you prefer. If your bitch is in distress, though, don’t hesitate to ring the veterinary surgery, whatever the time.

The Birth
The bitch will probably manage the whole process of whelping with the minimum of assistance from you, but watch for the various stages. Keep a detailed record of the times of:
    The First Stage
    Green Discharge
    Straining
    The Arrival of each puppy and its placenta

Stage 1: Dilation of the Cervix
In some bitches, this stage isn’t noticeable, but in others it may last between three and 24 hours.
Short contractions “short out” the fetuses and present the first one into the pelvis. This brings the fetal membrane into the cervix and stimulates it to open. The bitch is uncomfortable and restless, unable to settle and often frantically rearranges her bedding. She will probably pant, and her pulse quickens.

Stage 2: Expulsion of the Fetus
The total length of the second stage depends on the number of puppies. It rarely exceeds six hours and even with a large litter should not exceed 12.
When the first puppy enters the pelvis, contractions become stronger, longer and more frequent. The bitch’s hind legs often straighten out during the strongest waves of contraction. She may empty her bladder at this stage.

Eventually the water bag is pushed out. Sometimes the first puppy will be pushed through the sac membrane before it shows externally, and you’ll see a little gush of liquid. The bitch will rupture the sac if it has appeared and may pull with her teeth on any visible membrane. These membranes give the birth canal a slippery lining to ease the passage of the puppies.

By this time, the bitch is normally lying down. She turns frequently to clean herself; each turn is accompanied by a powerful contraction. Don’t rush to help, but observe the bitch from a distance. Some neurotic bitches need their owner at their side giving reassurance but not interfering. These are in the minority, though; other bitches are definitely put off by the presence of their owner.

Don’t panic if the puppy arrive rear end first – up to 40 percent of puppy births are breach. Once the head or rear of the puppy is visible, the bitch may give a short pause before expelling it.

The Puppy First
A maiden bitch usually produces her first puppy within three or four hours of beginning to strain. When the puppy arrives, she’ll clean it vigorously, licking it all over. This removes all the membranes which the bitch usually eats; she also chews off the umbilical cord. The puppy, stimulated by this cleaning activities and the air in its nostrils soon seeks out nipple and immediately begins to suck, helping to promote the supply of milk.
The puppy’s placenta may come out with it, or follow up to 15 minutes later. (Where there are many puppies, one may bring with it the placental membranes of previous puppies.)

The rest of the litter
The second puppy follows at any time up to two hours later. Occasionally it may be longer, but you should seek veterinary advice after a delay of two hours. Rest periods between the puppies usually get shorter. If the litter is very large – 12-14 puppies – the bitch may “take a couple of hours off” in the middle. A bitch with experience of whelping gets it over more quickly. The process of expulsion is often quicker and easier, with shorter rests between puppies.

Stage 3: Expulsion of Membranes
This is a complex phase where there is more than one puppy. Placental membranes are usually passed within 15 minutes of each puppy. They may arrive along with next puppy.

The bitch will probably attempt to eat these placentas. This won’t do her any harm – she may vomit them up later or have green diarrhea. If you can collect some of them without causing her too much distress, do so, although this isn’t essential. It’s more important to make sure the same numbers of placentas are passed as puppies produced.

The Caesarean
Your vet will decide if and when a Caesarean section is necessary. Although all general anesthetics carry a small degree of risk, this operation is nothing to worry about. No vet would advise it unless it was the safest available option.

You will have to transport the bitch to the veterinary surgery. Often, you’ll be able to wait at the surgery and take the bitch and any puppies home 1 ½ to 2 ½ hours after the start of the operation. At night, you might even be able to asked to help veterinary staff revive the puppies.

A Caesarean involves making an incision in the midline of the belly, or in the flank, removing the puppies from the uterus and stitching up the incision. Once the bitch is home, check this incision several times daily and report any problems to the vet.

Care of the New Mother
Most bitches have a slight bloody/green discharge for at least 24 hours after whelping. After a birth of a large litter, this can last up to a week. Bathe it off with an antiseptic wash. If it persists, consult your vet.

The bitch may also vomit or have diarrhea due to eating placentas. If you take care not to give her too fatty a diet, this should settle down.

A heavily lactating bitch needs up to three times as much food as normal. For her to ea this amount, it must be presented almost continually, and should include good quality protein, plus supplementary vitamins and minerals.

Mammary Glands
Check the mammary glands for mastitis (painful, red swollen area). You’ll have an opportunity to do this when the bitch leaves the puppies to go and relieve herself. Report any symptoms to your vet. Abnormal swelling normally occurs 24 to 48 hours after whelping. Bathe the glands in warm water and draw off excess milk by alternatively squeezing and releasing (to allow refilling) around the nipple. The problem usually sorts itself out as soon as the puppies start taking more milk.