Canine reproduction is the process of
sexual reproduction
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote tha ...
in
domestic dog
The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is Domestication of the dog, derived from the extinct Pleistocene wolf, and the modern wolf is the dog's n ...
s,
wolves
The wolf (''Canis lupus''; plural, : wolves), also known as the gray wolf or grey wolf, is a large Canis, canine native to Eurasia and North America. More than thirty subspecies of Canis lupus, subspecies of ''Canis lupus'' have been reco ...
,
coyote
The coyote (''Canis latrans'') is a species of canis, canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecologica ...
s and other
canine species.
Canine sexual anatomy and development
Male reproductive system
Erectile tissue
As with all mammals, a dog's penis is made up of three pieces of
erectile tissue Erectile tissue is tissue in the body with numerous vascular spaces, or cavernous tissue, that may become engorged with blood. However, tissue that is devoid of or otherwise lacking erectile tissue (such as the labia minora, the vestibule/vagina an ...
. These are the two ''
corpora cavernosa'' and the singular ''
corpus spongiosum '' which continues in the
glans
The glans (, plural "glandes" ; from the Latin word for "acorn") is a vascular structure located at the tip of the penis in male mammals or a homologous genital structure of the clitoris in female mammals.
Structure
The exterior structure ...
. A notable difference from the human penis is that the visible part during an erection consists entirely of the glans.
The
Retractor muscle is attached at the shaft of the penis. It is a paired
smooth muscle
Smooth muscle is an involuntary non-striated muscle, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit mus ...
that is used to retract the penis back into the
sheath.
Glans
A dog's
glans
The glans (, plural "glandes" ; from the Latin word for "acorn") is a vascular structure located at the tip of the penis in male mammals or a homologous genital structure of the clitoris in female mammals.
Structure
The exterior structure ...
consists of two sections: Behind the lower, long part (''
pars longa glandis'') lies the "knot" (''
Bulbus glandis
The bulbus glandis (also called a bulb or knot) is an erectile tissue structure on the penis of canid mammals. During mating, immediately before ejaculation the tissues swell up to lock ('' tie'') the male's penis inside the female. The locking i ...
'')
which expands only after penetrating the vagina and causes the male dog to remain inside the bitch ("Tie") for some time after
ejaculation
Ejaculation is the discharge of semen (the ''ejaculate''; normally containing sperm) from the male reproductory tract as a result of an orgasm. It is the final stage and natural objective of male sexual stimulation, and an essential componen ...
(typically between 15 and 30 min). This increases the chance of
fertilisation
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...
and prevents, albeit for a short time, other suites from mating with a particular female.
Behind the knot the penis is very flexible in the horizontal direction allowing the male to unmount while remaining tied.
Shaft
The shaft of a dogs penis is not visible, even during an erection; however its pathway can be felt starting at the knot passing between the hind legs and carrying on up to the anus.
Baculum and Urethra
![Armand de Montlezun Baculum Pyrénées](https://upload.wikimedia.org/wikipedia/commons/b/b2/Armand_de_Montlezun_Baculum_Pyr%C3%A9n%C3%A9es.jpg)
Inside the corpus spongiosum lies the
baculum. This allows the male dog to enter into the vagina before the erectile tissue is swollen. The
urethra
The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra con ...
is located inside of a downward facing groove on the baculum and ends at the tip of the penis (''urethral process'').
During an erection a small dip just above the urethral process can be seen. This is because the skin at the tip of the penis is connected via cartilage to the baculum. When the erectile tissue swells, the size of the baculum and connective tissue remains constant, pulling back the skin at the tip.
Sheath
The
penile sheath
Almost all mammal penises have foreskins or prepuce, although in non-human cases the foreskin is usually a sheath (sometimes called the ''preputial sheath'', ''praeputium'' or ''penile sheath'') into which the whole penis is retracted. In koalas ...
entirely surrounds the glans while not erect. The back part is intergrown with the abdominal skin. The front part, almost reaching to the
navel
The navel (clinically known as the umbilicus, commonly known as the belly button or tummy button) is a protruding, flat, or hollowed area on the abdomen at the attachment site of the umbilical cord. All placental mammals have a navel, although ...
, is free. The inner sheath, just like the glans, is covered with a
mucous membrane
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...
and the outer sheath is covered with normal, hairy
epidermis
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...
.
Female reproductive system
Development
In domestic dogs, sexual maturity (
puberty
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. ...
) occurs between the ages of 6 to 12 months for both males and females, although this can be delayed until up to two years of age for some large breeds. Pregnancy is possible as soon as the first
estrus cycle
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous p ...
, but breeding is not recommended prior to the second cycle.
As with other domesticated species,
domestication
Domestication is a sustained multi-generational relationship in which humans assume a significant degree of control over the reproduction and care of another group of organisms to secure a more predictable supply of resources from that group. ...
has selectively bred for higher
libido
Libido (; colloquial: sex drive) is a person's overall sexual drive or desire for sexual activity. Libido is influenced by biological, psychological, and social factors. Biologically, the sex hormones and associated neurotransmitters that act up ...
, and earlier and more frequent breeding cycles in dogs than in their ancestors.
The female reproductive cycle
Female cycle
The average length of the
reproductive
The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are als ...
cycle for females is 2–4 weeks. Females reach sexual maturity (puberty) between 8 and 18 months of age. There is a tremendous variability in the maturation age between breeds, and even within a breed of dog.
, Dr B Eilts, LSU Veterinary Medicine, "The Normal Canine Estrous Cycle" retrieved 10 April 2013.
1. Proestrus, in which eggs in the ovaries begin to mature and estrogen levels begin to rise, is the first stage of the reproductive cycle. During this stage females, though non-receptive, attract males. Initial changes include swelling of the vulva lips, which become pliable, small amounts of bloody vaginal discharge, frequent urination, and signs of restlessness. Proestrus generally lasts nine days.
2. Estrus follows, in which estrogen levels are high, mature eggs are released from both ovaries, and females become receptive both physically and mentally to
animal sexual behavior, copulation. Only during estrus will copulation result in pregnancy.
During proestrus and estrus, females may have a clear, blood tinged, or bloody discharge. Dogs during these stages are often informally referred to as being in heat. The length of these cycles varies greatly among breeds and even between individuals of the same breed. Proestrus and estrus can last anywhere from 5 days to 21 days.
3.
Diestrus
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous ...
is the period following mating. Diestrus lasts approximately 56 to 60 days in a pregnant female, and 60 to 100 days in a non-pregnant female. During both of these periods, progesterone levels are high. Because the hormonal profile of a pregnant female and a female in diestrus are the same, sometimes a non-pregnant female will go through a period of
pseudo-pregnancy
High-dose estrogen (HDE) is a type of hormone therapy in which high doses of estrogens are given. When given in combination with a high dose of a progestogen, it has been referred to as pseudopregnancy. It is called this because the estrogen and p ...
. At that time she may gain weight, have
mammary gland development
Breast development, also known as mammogenesis, is a complex biological process in primates that takes place throughout a female, female's life.
It occurs across several phases, including prenatal development, puberty, and pregnancy. At menopau ...
, produce milk, and exhibit nesting behaviours.
4. Anestrus is the remaining period, the time of reproductive quiescence. The female has no attraction to mating. Anestrus generally lasts four to five months.
Copulation
![Korean wolves mating (cropped)](https://upload.wikimedia.org/wikipedia/commons/a/af/Korean_wolves_mating_%28cropped%29.jpg)
As with most
tetrapod
Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids ( reptiles, including dinosaurs and therefore birds) and synapsids (pelycosaurs, extinct theraps ...
s, canine
animal sexual behavior, copulation involves the male mounting the female from behind, a position that is colloquially referred to as "
doggy style
Doggy style is a sex position in which a person bends over, crouches on all fours (usually on hands and knees), or lies on their abdomen, for sexual intercourse, other forms of sexual penetration or other sexual activity. Doggy style is a ...
" but does not have a specifically known origin. When a male canine is interested in mounting a female, he will sniff the female's
vulva
The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external sex organ, female sex organs. The vulva includes the mons pubis (or mons veneris), labia majora, labia minora, clitoris, bulb of vestibu ...
.
If the female is unreceptive, she may sit, lie down, snap, retreat, or otherwise be uncooperative. If the female is receptive, she will stand still and hold her tail to the side, a stance referred to as "flagging".
The male will often continue examining the female's rear, before mounting her from behind while attempting
penetration with
his penis.
Unlike human sexual intercourse, where the male penis commonly becomes erect before entering the female, canine
copulation
Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetrat ...
involves the male first penetrating the female, after which swelling of the penis to erection occurs, which usually happens rapidly.
At the time of penetration, the
canine penis
Canine reproduction is the process of sexual reproduction in domestic dogs, wolves, coyotes and other canine species.
Canine sexual anatomy and development Male reproductive system Erectile tissue
As with all mammals, a dog's penis is made up o ...
is not
erect, and only able to penetrate the female because it includes a narrow bone called the "
baculum", a feature of most
placental mammal
Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguishe ...
s. When the male achieves penetration, he will usually hold the female tighter and thrust deeply.
It is during this time that the male's penis expands and it is important that the bulbus gland is sufficiently far inside for the female to be able to trap it.
![On Nut 54](https://upload.wikimedia.org/wikipedia/commons/c/c0/On_Nut_54.jpg)
Male
canines
Canine may refer to:
Zoology and anatomy
* a dog-like Canid animal in the subfamily Caninae
** ''Canis'', a genus including dogs, wolves, coyotes, and jackals
** Dog, the domestic dog
* Canine tooth, in mammalian oral anatomy
People with the surn ...
are the only animals that have a locking
bulbus glandis
The bulbus glandis (also called a bulb or knot) is an erectile tissue structure on the penis of canid mammals. During mating, immediately before ejaculation the tissues swell up to lock ('' tie'') the male's penis inside the female. The locking i ...
or "bulb", a spherical area of
erectile tissue Erectile tissue is tissue in the body with numerous vascular spaces, or cavernous tissue, that may become engorged with blood. However, tissue that is devoid of or otherwise lacking erectile tissue (such as the labia minora, the vestibule/vagina an ...
at the base of the
penis
A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do n ...
. During copulation, and only after the male's penis is fully inside the female's vagina, the bulbus glandis becomes engorged with blood.
When the female's
vagina
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen ...
subsequently contracts, the penis becomes locked inside the female.
This is known as "tying" or "knotting". While characteristic of mating in most canids, the copulatory tie has been reported to be absent
or very brief (less than one minute)
in the
African wild dog
The African wild dog (''Lycaon pictus''), also called the painted dog or Cape hunting dog, is a wild canine which is a native species to sub-Saharan Africa. It is the largest wild canine in Africa, and the only extant member of the genus '' Ly ...
, possibly due to the abundance of large predators in its environment.
When the penis is locked into the vagina by the bulbus glandis (when the
stud
Stud may refer to the following terms:
Animals
* Stud (animal), an animal retained for breeding
** Stud farm, a property where livestock are bred
Arts and entertainment
* Stud (band), a British progressive rock group
* The Stud (bar), a gay ba ...
is "tied"), thrusting behavior stops and the male will usually lift a leg and swing it over the female's back while turning around. The two stand with their hind ends touching and the penis locked inside the vagina while
ejaculation
Ejaculation is the discharge of semen (the ''ejaculate''; normally containing sperm) from the male reproductory tract as a result of an orgasm. It is the final stage and natural objective of male sexual stimulation, and an essential componen ...
occurs, decreasing leakage of
semen
Semen, also known as seminal fluid, is an organic bodily fluid created to contain spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize the female ovum. Semen i ...
from the vagina. After some time, typically between 5 and 20 minutes
(but sometimes longer), the bulbus glandis disengorges, allowing the mates to separate.
Virgin
Virginity is the state of a person who has never engaged in sexual intercourse. The term ''virgin'' originally only referred to sexually inexperienced women, but has evolved to encompass a range of definitions, as found in traditional, modern ...
dogs can become quite distressed at finding themselves unable to separate during their first copulation, and may try to pull away or run.
Dog breeders
The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...
often suggest it is appropriate for handlers to attempt to calm the mating dogs if they show anxiety once this stage is reached. After mating, the male usually licks his penis and prepuce.
Gestation and litters
![Pregnant bitch mongrel Jan 2008 Shot in Jalandhar Punjab India by gopal1035 017](https://upload.wikimedia.org/wikipedia/commons/4/48/Pregnant_bitch_mongrel_Jan_2008_Shot_in_Jalandhar_Punjab_India_by_gopal1035_017.jpg)
![Wilde huendin am stillen](https://upload.wikimedia.org/wikipedia/commons/a/ae/Wilde_huendin_am_stillen.jpg)
Gestation in a dog is 63 days in length, if measured from the day of ovulation. Since it is difficult to determine the exact date of ovulation, errors are often made in calculating gestation period.
[, Dr B Eilts, Louisiana State University Veterinary Medicine, "Canine Pregnancy" retrieved 10 April 2013.] Canine sperm can live for 10 to 11 days
in the uterine tubes (fallopian tubes) so if a female is bred 10 days before the oocytes (eggs) can be fertilized, she will appear to have a gestation length of 70 days. If she is bred on the day the oocytes can be fertilized, her gestation length will appear to be 60 days long.
A rule of thumb is that a mammal will produce half as many offspring as the number of teats on the mother. This rule is altered in domesticated animals since larger litters are often favoured for economic reasons and in dogs, particularly, the great range of sizes and shapes plays a role in how many healthy puppies a female can carry. A female dog usually has 10 teats, though this does not mean she can necessarily provide sufficient nutrition for 10 puppies in one litter.
An average litter consists of about five to six
puppies
A puppy is a juvenile dog. Some puppies can weigh , while larger ones can weigh up to . All healthy puppies grow quickly after birth. A puppy's coat color may change as the puppy grows older, as is commonly seen in breeds such as the Yorksh ...
, though this number may vary widely based on the breed of dog. Size of the breed is correlated with litter size. Miniature and small breeds average three to four puppies in each litter, with a maximum litter size of about 5–8. Large and giant breeds average 7 puppies per litter but can have a maximum litter size of about 15.
In one study, the
Rhodesian Ridgeback
The Rhodesian Ridgeback is a large dog breed bred in the Southern Africa region. Its forebears can be traced to the semi-domesticated ridged hunting and guardian dogs of the Khoikhoi. These were interbred with European dogs by the early colonist ...
had the highest average litter size with 8.9 pups per litter while the Pomeranian and Toy Poodle had the lowest with 2.4 pups per litter.
The number of puppies also varies with the mother's age. In smaller breeds, both young and old age are associated with smaller litter size. In larger breeds, only old age is associated with smaller litter size.
Use of artificial insemination is also associated with smaller litter size, with frozen semen having a stronger effect than fresh semen.
The largest litter size to date was set by a
Neapolitan Mastiff
The Neapolitan Mastiff or is an Italian breed of large dog of mastiff type. It descends from the traditional guard dogs of central Italy. It was recognised as a breed by the Ente Nazionale della Cinofilia Italiana in 1949, and accepted by the F ...
in
Manea Manea may refer to:
* Manea, Cambridgeshire, a village in the District of Fenland, Cambridgeshire, England
* Manea (name), both a surname and a given name
* MANEA, an enzyme
* Manea River, a tributary of the Crasna River in Romania
* a singular f ...
, England on November 29, 2004; the litter was 24 puppies.
Some breeds have been developed to emphasize certain physical traits beyond the point at which they can safely bear litters on their own.
A large scale study in Norway showed that across all breeds, about 4% of pups will be stillborn and a further 4% will die within the first week (early neonatal mortality). Between 8 days and 8 weeks, 1% will die. Litter size, breed size and age of the female is associated with increased risk. High risk breeds for stillborn includes the Dogue de Bordeaux (14.2%), St. Bernard (12.3%), Chow Chow (12.1%), Pembroke Welsh Corgis (11.7%) and Dalmatian (10.6%). The Basenji, Italian Greyhound, Australian Terrier, Irish Soft Coated Wheaten Terrier and the Bichon Havanais had few to no stillborns (0-0.6%). High risk breeds for early neonatal mortality includes the Rhodesian Ridgeback (11.6%), Dogue de Bordeaux (10.4% ), Dalmatians (8.8%) and Icelandic Sheepdog (8.7%) while the Basenji and Tibetan Terrier had no early neonatal mortality and the Border Terrier and Danish-Swedish Farmdog had <1% early neonatal mortality.
Common causes of early neonatal mortality are bacteria infection, fetal asphyxia and
fading puppy syndrome
Fading puppy syndrome (or fading puppy complex) is when a puppy dies within the first few weeks of life without a clear cause of death or clinical signs, that is to say, they fail to thrive. Death usually occurs within the first five days of life, ...
. Other causes may include elective euthanasia because of congenital defects or failure to meet
breed standards
In animal husbandry or animal fancy, a breed standard is a description of the characteristics of a hypothetical or ideal example of a breed. The description may include physical or morphological detail, genetic criteria, or criteria of athletic ...
.
Other multi-breed studies have put stillborn rates at 6.5-7% and early neonatal mortality at 11.5-19.8%.
Inbreeding depression
On the basis of an analysis of data on 42,855
dachshund
The dachshund ( or ; German: "badger dog"), also known as the wiener dog, badger dog, and sausage dog, is a short-legged, long-bodied, hound-type dog breed. The dog may be smooth-haired, wire-haired, or long-haired, and comes in a variety of c ...
litters, it was found that as the
inbreeding coefficient
The coefficient of inbreeding of an individual is the probability that two alleles at any locus in an individual are identical by descent from the common ancestor(s) of the two parents.
The coefficient of inbreeding is: The probability that two ...
increased, litter size decreased and the percentage of stillborn puppies increased, thus indicating
inbreeding depression
Inbreeding depression is the reduced biological fitness which has the potential to result from inbreeding (the breeding of related individuals). Biological fitness refers to an organism's ability to survive and perpetuate its genetic material. In ...
.
Inbreeding depression is a reduction in progeny fitness due largely to the
homozygous
Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism.
Mo ...
expression of deleterious recessive mutations.
Inbreeding avoidance
Because the
African wild dog
The African wild dog (''Lycaon pictus''), also called the painted dog or Cape hunting dog, is a wild canine which is a native species to sub-Saharan Africa. It is the largest wild canine in Africa, and the only extant member of the genus '' Ly ...
(''Lycaon pictus'') largely exists in fragmented small populations, its existence is endangered.
Inbreeding avoidance
Inbreeding avoidance, or the inbreeding avoidance hypothesis, is a concept in evolutionary biology that refers to the prevention of the deleterious effects of inbreeding. Animals only rarely exhibit inbreeding avoidance. The inbreeding avoidance ...
via mate selection is characteristic of the species and has important potential consequences for population persistence.
Inbreeding is rare within natal packs. Computer-population simulations indicate that all populations continuing to avoid incestuous mating will become extinct within 100 years due to the unavailability of unrelated mates.
Thus the impact of reduced numbers of suitable unrelated mates will likely have a severe demographic impact on the future viability of small wild dog populations.
Red wolves
The red wolf (''Canis rufus'') is a canine native to the southeastern United States. Its size is intermediate between the coyote (''Canis latrans'') and gray wolf (''Canis lupus'').
The red wolf's taxonomic classification as being a separate sp ...
primarily live in packs composed of a socially
monogamous
Monogamy ( ) is a form of Dyad (sociology), dyadic Intimate relationship, relationship in which an individual has only one Significant other, partner during their lifetime. Alternately, only one partner at any one time (Monogamy#Serial monogamy, ...
breeding pair and offspring of different ages. Using long-term data on red wolf individuals of known pedigree, it was found that inbreeding among first-degree relatives was rare.
A likely mechanism for avoidance of inbreeding is independent dispersal trajectories from the natal pack. Many of the young wolves spend time alone or in small non-breeding packs composed of unrelated individuals. The union of two unrelated individuals in a new home range is the predominant pattern of breeding pair formation.
Among
Ethiopian wolves, most females disperse from their natal pack at about two years of age, and some become "floaters" that may successfully immigrate into existing packs. Breeding pairs are most often unrelated to each other, suggesting that female-biased dispersal reduces inbreeding.
Grey wolves and Arctic foxes also exhibit inbreeding avoidance.
Inbreeding is ordinarily avoided because it leads to a reduction in progeny fitness (inbreeding depression) due largely to the homozygous expression of deleterious recessive alleles.
Cross-fertilization between unrelated individuals ordinarily leads to the masking of deleterious recessive alleles in progeny.
Clinical issues
Female dogs are at risk for
endometritis
Endometritis is inflammation of the inner lining of the uterus ( endometrium). Symptoms may include fever, lower abdominal pain, and abnormal vaginal bleeding or discharge. It is the most common cause of infection after childbirth. It is also p ...
and
pyometra
Pyometra or pyometritis is a uterine infection. Though it is most commonly known as a disease of the unaltered female dog, it is also a notable human disease. It is also seen in female cattle, horses, goats, sheep, swine, cats, rabbits, hamsters, ...
in the
postpartum
The postpartum (or postnatal) period begins after childbirth and is typically considered to end within 6 weeks as the mother's body, including hormone levels and uterus size, returns to a non-pregnant state. The terms puerperium, puerperal perio ...
period and after
estrus
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous p ...
or
vaginitis
Vaginitis, also known as vulvovaginitis, is inflammation of the vagina and vulva. Symptoms may include itching, burning, pain, discharge, and a bad smell. Certain types of vaginitis may result in complications during pregnancy.
The three main ...
. Signs and symptoms include fever, lethargy, loss of appetite, excessive thirst, restlessness, a foul smelling vaginal discharge which may or may not be bloody, infertility, or they may be asymptomatic.
Uterine infections should be treated expeditiously if suspected. Contrary to common belief, uterine infections can strike any intact female, whether she has been bred or not, and whether it is her first season or not although it is more common as dogs become older.
Dog breeding
Semen collection
An
artificial vagina
An artificial vagina is a device designed to imitate the female sex organ. To achieve this, it will generally be made of a soft material, lubricated, and sometimes heated.
There are different types of artificial vaginas. They may be designed ...
is prepared, which is a conical thin latex sleeve ending in a sterile collection tube. The inside of the latex sleeve is lightly lubricated. The male is allowed to sniff a female in estrus. Experienced studs cooperate readily in the process. New studs often require encouragement in the form of manual stimulation.
Generally the male will mount the female, and the collector quickly directs the male's penis into the latex sleeve. The male
ejaculates
Ejaculation is the discharge of semen (the ''ejaculate''; normally containing sperm) from the male reproductory tract as a result of an orgasm. It is the final stage and natural objective of male sexual stimulation, and an essential componen ...
and the
semen is collected in the tube. The semen is then drawn up into a long thin pipette.
Cross breeding
Designer breed dogs are
Mixed-breed dogs
A mongrel, mutt or mixed-breed dog is a dog that does not belong to one officially recognized breed and including those that are the result of intentional breeding. Although the term ''mixed-breed dog'' is sometimes preferred, many mongre ...
that are intentionally bred from parents of two established breeds. Studies have shown that cross-bred dogs have a number of desirable reproductive traits. Scott and Fuller
found that cross-bred dogs were superior mothers compared to purebred mothers, producing more milk and giving better care. These advantages led to a decreased mortality in the offspring of cross-bred dogs; however, the qualities of cross bred dogs are not predictable. For example, Labrador x Poodle ("
Labradoodle
A Labradoodle () is a crossbreed dog created by crossing a Labrador Retriever and a Standard, Miniature, or Toy Poodle. The term dates back to at least 1955 but was unpopular at the time. Labradoodles are considered a good choice for people with ...
") can inherit the coat of either a Labrador, a poodle, or a remix.
Spaying and neutering
Spaying (females) and neutering (males) refers to the
sterilization of animals—usually by castration (removal of the male's
testicle
A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testostero ...
s) or ovariohysterectomy (removal of the female's
ovaries
The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...
and
uterus
The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The uter ...
)—to eliminate the ability to procreate, and reduce
sex drive
Libido (; colloquial: sex drive) is a person's overall sexual drive or desire for sexual activity. Libido is influenced by biological, psychological, and social factors. Biologically, the sex hormones and associated neurotransmitters that act upo ...
. Castration has also been known to reduce aggression in male dogs (in some cases), but spaying has been shown to occasionally increase aggression in female dogs.
Animal control agencies in the United States and the
ASPCA
The American Society for the Prevention of Cruelty to Animals (ASPCA) is a non-profit organization dedicated to preventing animal cruelty. Based in New York City since its inception in 1866, the organization's mission is "to provide effective mea ...
advise that dogs not intended for further breeding should be spayed or neutered so that they do not have undesired puppies. Spaying and castrating can decrease the risk of hormone-driven diseases such as mammary cancer, as well as undesired hormone-driven behaviors.
However, certain medical problems are more likely after neutering, such as
urinary incontinence
Urinary incontinence (UI), also known as involuntary urination, is any uncontrolled leakage of urine. It is a common and distressing problem, which may have a large impact on quality of life. It has been identified as an important issue in geria ...
in females and
prostate cancer
Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that sur ...
in males.
Dogs shown in the
conformation ring are not allowed to be either neutered or spayed. It disqualifies them from being shown as they must be intact and unaltered.
Female cats and dogs are seven times more likely to develop
mammary tumor
A mammary tumor is a neoplasm originating in the mammary gland. It is a common finding in older female dogs and cats that are not spayed, but they are found in other animals as well. The mammary glands in dogs and cats are associated with their n ...
s if they are not spayed before their first
heat cycle.
Studies have shown that spaying or neutering may be associated with increasing some serious health and behavioural consequences while reducing others. The American Veterinary Association (AVMA) position provides no single recommendation to spay or neuter nor for one single age for spay or neuter that is more or less optimal than another. Rather, the AVMA position is that spay or neuter be determined on a case-by-case basis to assess risks for orthopedic disease, neoplasia, reproductive disease, longevity, and population control for each individual.
Altered females:
Increased aggression can be shown in altered females if they have previously displayed aggression prior to surgical alteration. In a study by O'Farrell and Peachy, female dogs less than 11 months of age that had previously shown signs of aggression are more likely to have an increase in aggression after being spayed.
These increases in aggression may be due to the sudden change in hormone concentrations that are the result of alteration. While spaying female dogs does not "induce" aggression, it can increase aggression and facilitate indiscriminate appetite in young altered females and can include them rapidly eating meals or eating food-associated items such as trash.
Altered males:
In nearly 2/3 of the cases that involve inter-dog aggression, castration can help decrease aggression. Castration also decreases other male-typical behavioral traits such as mounting, roaming, and urine marking. But a few studies have shown that male behavioral issues of mounting, roaming and urine marking still exist in altered males. Some people have reported after altering their male dogs that behavior such as roaming, mounting and urine marking has not changed the behavior. Aggression may increase, as the decrease in testosterone may lead to emotional issues and become more likely to react aggressively when feeling under threat.
Male puppies that are neutered between 7 and 10 weeks are three times less likely to display behavioral problems, compared to canines neutered at 6 months or older.
Most dominantly aggressive dogs are male, which causes many people to neuter their male canine companions. Removing testosterone can decrease the intensity of a canine's reaction to stimulus. Testosterone does not cause a behavior to occur, but its absence may decrease the occurrence of a "bad" behavior.
See also
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Canine reproductive behavior
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Canine transmissible venereal tumor
A canine transmissible venereal tumor (CTVT), also known as a transmissible venereal tumor (TVT), canine transmissible venereal sarcoma (CTVS), sticker tumor and infectious sarcoma, is a histiocytic tumor of the external genitalia of the dog and ...
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Animal husbandry
Animal husbandry is the branch of agriculture concerned with animals that are raised for meat, fibre, milk, or other products. It includes day-to-day care, selective breeding, and the raising of livestock. Husbandry has a long history, starti ...
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Puppy mill
A puppy mill, also known as a puppy farm, is a commercial dog breeding facility characterized by quick breeding and poor conditions. Although no standardized legal definition for "puppy mill" exists, a definition was established in ''Avenson v. ...
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Sexual behavior of coyotes
The coyote (''Canis latrans'') is a species of canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecological nic ...
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Sexual behavior of golden jackals
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Sexual behavior of red foxes
The red fox (''Vulpes vulpes'') is the largest of the true foxes and one of the most widely distributed members of the Order (biology), order Carnivora, being present across the entire Northern Hemisphere including most of North America, Europe ...
References
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Further reading
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External links
Canine Gestation Calculator
{{DEFAULTSORT:Canine Reproduction
Dog breeding
Reproduction
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual or ...
Dogs
Reproduction in mammals
Theriogenology