Learning About Dog Breeding
Dog breeding is a very gratifying occupation if we study the breed of choice, make our breeding stock selections carefully, and apply good management techniques to our breeding program. Before beginning, we should learn as much as we can about the breeding process and raising puppies. As we study our particular breeds of dogs and what makes them great, we must also study the specifics of canine reproduction.
This book was designed to walk you through the many phases of breeding dogs in a generic way. We mention a few specific breeds as they relate to breeding or whelping problems, but our purpose is to educate you in every aspect of dog breeding, regardless of the breed you choose.
We have an ulterior motive as well. Sometimes, in spite of your best intentions, you find yourself with a pregnant bitch. She may be an expensive purebred, or a shopping basket give-away mongrel, but she is a well-loved member of your family. Quite by accident, your female puppy suddenly became a mature young lady who spent an adventuresome half hour romping in the park with some canine friends. A few weeks later it becomes obvious that she is in a “family way.” After consulting with a veterinarian (see Pregnancy Termination, page 74), you decide to accept the responsibility of raising a litter of unwanted puppies.
This book was also written for you. It discusses the prediction of whelping time, normal deliveries, whelping problems, and emergencies. Whelping assistance techniques are described. You are told when to observe, when to intervene, how to help solve a problem, and when to call professional help.
Owner Responsibility
No matter whether you are a professional dog breeder, a novice, a potential breeder, or a pet owner who is unintentionally thrown into the dog breeder class due to the indiscretion of your female dog, you must accept the responsibility to care for your dog and her offspring to the very best of your ability.
After accepting that precept, I offer you many years of practical experience and knowledge on the following pages.
Chapter 2
When to Breed
Seasonality of Heats
Canine reproductive biology is somewhat unique. The bitch is monestrous (having one estrus period each season), showing no seasonality of estrous cycles in most breeds. Unlike some wild carnivores, environmental temperature and climatic changes have little or no effect on domestic canine estrous. They may start their first heat period at any time of the year, whether kept in your home, outside, or in a kennel.
It is generally accepted among breeders and canine reproductive specialists that the preferred time to breed a bitch is two days after ovulation. As you will see, calculating that time in an individual bitch is not quite as easy as making the generalization.
Possible Breeding Times
Bitches can be bred during any normal heat cycle, including their first. It is a generally accepted precept that first-heat breeding is a poor practice, but sometimes it happens in spite of our good intentions. The best rule to follow when intentionally breeding a bitch is to be sure she is physically mature and mentally stable. That means she is over a year old, and depending on the breed, perhaps closer to two years, by which time she should be in her second or third heat period.
Most professional dog breeders do not include animals in their breeding program until they prove their superior qualities in bench shows or obedience competition. Working and hunting breeds likewise are rarely bred before they compete and win in the field. Certainly the overpopulation of dogs demands that we intentionally breed only those animals that are excellent representatives of the breed.
Estrous Cycle
Please note that two very similar words are used frequently in this book. The word spelled with an “o” (estrous) refers to females’ reproductive cycles. It includes all reproductive phases of intact (unspayed) bitches’ lives. Another word that is pronounced identically (estrus) is spelled without an “o,” and refers to “standing heat” periods, which are the second specific phases of estrous cycles. It is important to understand the differentiation. I will endeavor to use estrous only in combination with the word “cycle.”
This bitch in heat is wearing a diaper and looking wistfully out the back door.
Phases of the Estrous Cycle
Canine heat cycles are divided into four separate phases. Each phase has specific outward signs associated with it, as well as attitude, hormonal, and other internal changes. The paragraphs discussing hormone changes may seem academic, but if you read them carefully, you will find the information fascinating. The hormone discussion allows one to more fully understand the attitude and appearance changes of the bitches as they progress through their estrous cycles.
Blood serum hormone levels can best be determined by laboratory analysis using a technique called radioimmunoassay (RIA). Other techniques are adapted for home use. The home ELISA (enzyme-linked immunoabsorbent assay) test for progesterone is less accurate, but often valuable if interpreted correctly.
Proestrus
The first estrous cycle phase is called proestrus. Its outward, physical signs are obvious. All the female’s reproductive tissues thicken, her vulva swells, and visible genitalia becomes reddened. Bloody vaginal discharges are produced, and the bitch usually spends an extraordinary amount of time licking her external genitalia. She may act nervous and her appetite is reduced. In early proestrus, some bitches are snappy toward other animals.
As the days of proestrus count down, she tries to escape from confinement, seeking a mate. The bloody discharge attracts males from near and far. If housed with intact males, they will begin paying court to the bitches. If females are allowed outside, male dog visitors should be expected.
Prior to puberty, intact bitches’ internal reproductive organs (except their ovaries) are quite undeveloped. The actual weight and dimensions of prepuberal (before the first heat) uteruses are significantly smaller than those of sexually mature animals. As puberty is reached and proestrus begins, the uterus enlarges in response to hormones secreted from the ovaries. Although that enlargement is unapparent to the owner, it can sometimes be palpated by veterinarians with practiced fingers, and it is easily demonstrated by ultrasound imaging.
Proestrus lasts from two to 27 days, more typically seven to ten days. The average length of proestrus is generally accepted to be nine days.
During this phase, estrogen hormone levels rise gradually in the bloodstream, and levels of the progesterone hormone remain relatively low.
This Cavalier King Charles Spaniel has a rather large litter of six fine puppies.
Another hormone called follicle stimulating hormone (FSH) originates from the pituitary gland. For two or three weeks prior to the onset of proestrus, serum levels of FSFI rise. Its effect is to stimulate production of follicles within the ovaries. These follicles contain microscopic eggs called ova.
Estrus
The next phase of the reproductive cycle is termed estrus. It corresponds to the stage often referred to as “standing heat,” when bitches will stand for breeding. It lasts from extremes of two to 21 days, more typically six to ten days, and averages nine days. It is during estrus that a bitch will mate with a male; spontaneous ovulation takes place