Dog Manual

The Unconventional Love Life of Your Dog

Suppose I told you that a dog does not have a sex life? You— who are an old observer of dogs on the prowl—would probably suggest that I must be slightly off the beam. And yet, that is exactly what I am going to tell you.

We really cannot consider the sex life of the dog in the same sense that we consider the sex life of human beings. In the strictest meaning of the term, it must be said that a dog does not have a sex life at all. The very least that a sex life seems to imply are a freedom of choice of sexual partner; a certain regularity of sexual routine; and a conscious direction, anticipation, and planning of future sexual activity. While it may be said that a stray or free-roving dog does have relative freedom of choice and also a blatantly immodest regularity in this regard, the likelihood of conscious direction, anticipation, and planning of future sexual activity is rather remote.

House pets or breeding animals are even deprived of the freedom of choice or of any consistent regularity, for these animals are permitted to engage in sexual activity only at the whim and fancy of the individual owner. Therefore, while it may be said that a dog does not have a sex life, properly-so-called, it certainly cannot be denied that a dog engages in sexual activities. It is the purpose of this chapter to consider some uncommonly discussed aspects of the sexual behavior of the dog from the standpoint of the random observations and casual reading of an ordinary veterinary practitioner.

It must also be added that, while I do not intend to offend the sensibilities of dog lovers, some observations on the cat will also have to be included whenever specific parallel data on the dog cannot be given. This has to be done because the cat has sometimes been more amenable to certain kinds of experimentation on sexual behavior. None the less, both dog and cat can teach us something about the sexual behavior of one another. We have no alternative but to take our basic information wherever it happens to be available.
An animal activity is said to be instinctive when the activity is performed perfectly, from the very first time that it is done, without any previous learning. All activities that require learning before they can be performed well cannot be said to be instinctive.

 Thus a beaver builds a dam by instinct; ants build their hills by instinct; homing pigeons return home by instinct, and so on. But man learns to drive a car, to fly a plane, to play the piano. He emphatically does not perform these activities instinctively. In addition, there are some activities that are only partly instinctive since some learning is required to bring them to full fruition. Sexual activity in the dog is one of these.

Sexual activity in the dog is partially instinctive and partially learned. It is instinctive to the extent that it is an unlearned, fundamental, biological impulse. It is not instinctive insofar as some learning is required to render that impulse functionally adequate. In primitive animals that are far below the evolutionary status of the dog, sexual activity is purely instinctive in nature. Upon reaching puberty, these lower animals carry out their sexual functions to utter perfection without any learning whatsoever. The sexual impulse in these lower animals is perfectly and completely inherited. In dogs, on the other hand, the sexual impulse is only imperfectly inherited, and a certain amount of learning is required in order that those sexual activities necessary to the propagation of the species be adequately carried out. This seems to be more evident in the male than in the female.

In its prepuberal life—that is, in the period before sexual maturity—the female dog never exhibits any of its adult sexual patterns, but when it attains puberty it carries out its sexual functions, from the very beginning, with an admirable competence. The male, on the other hand, exhibits an abundance of its adult sexual patterns in its prepuberal existence. It mounts its companions in typical, male mating fashion, indulges in pubic thrusts and convulsive pubic movements, and seems to make every effort to learn to prepare itself to become a male adult. None the less, upon reaching puberty, it ordinarily carries out its sexual functions with an extreme awkwardness and seems to require at least a modest amount of sexual experience before it can become an effective partner in the sexual act.

These observations suggest that sexual activity is more of an instinctive manifestation in the female than it is in the male; that is, that learning is required in the male to support its instinctive sexual impulses, whereas it does not appear to be required (at least not to such a degree) in the female. This conclusion is further supported by experimental evidence in studies on the brain of the dog. The portion of the brain that is concerned with higher intellectual functions, such as learning, memory, imagination and the like, is called the cerebral cortex. If this portion of the brain is removed, these intellectual functions cease to exist. Now when it is removed from the dog, the female continues to engage in its normal sexual activities while the male exhibits no sexual interest whatsoever. The implication is that learning is essential to the sexual behavior of the male dog and not to the female.

This fact also helps to explain why male dogs commonly show greater discrimination in the choice of a sexual partner than a female at the highest point of heat, and also why males are more apt to be sexually disturbed than females by sudden changes in the immediate area where the sexual activity takes place. The role of the female in sex being essentially passive, when she is in heat she is simply ready for the acceptance of the male. But the role of the male is essentially active and he must always be ready for the female who comes in heat. The male must achieve and maintain an erection. This fact, along with the cerebral connection of the male with sex, makes it logical that the male requires the more favorable situation for achieving sexual completion and that it can be readily disturbed by unfavorable circumstances. It is apparent, therefore, that while the sexual impulse has an instinctive basis, a certain amount of learning is required to render that impulse functionally adequate.

The question may be rightfully raised at this point why a higher animal should inherit an instinct less perfectly than a lower one. Since there are certain functions that are essential to life, should not a higher animal inherit the predispositions to these functions even more perfectly than a lower one? Why should the opposite be the case? The reason for this apparent inconsistency is that it is one of the ways in which the progressive mental evolution of animal species from lower to higher forms was rendered possible. Whereas lower animals inherit their instincts to absolute perfection so that life's activities can be adequately carried out without any form of learning, these instincts become increasingly less perfectly inherited the higher the animal progresses in its evolutionary development.

The logic of the process is simply this: if the instincts necessary to survival were always perfectly inherited, there would be no need for further mental development. All of life's problems could be satisfactorily met on an instinctive level. Where instincts were only imperfectly inherited, the animal world was stimulated to exercise its mental capacities in order to cope with the problems of life. In this way, the less perfectly inherited were the instincts, the greater was the necessity and the possibility of further mental development. There are, of course, additional factors in the stimulation of evolutionary mental development, but the way just described was very likely of very considerable importance.

However imperfectly these instincts were inherited, they still persisted. They were apparently necessary for the continued survival of the species. And since they were imperfectly inherited, they had to be supplemented by learning in order to bring them to full fruition. If this did not occur, the species was doomed unless some drastic and favorable change in the inheritance pattern took place. Sexual behavior in the dog exemplifies rather typically how learning supplements an imperfectly inherited sexual impulse.

In the interpretation of animal sexual activity, we have no way of probing into the conscious or subconscious mind of the animal to determine whether its behavior is subjectively sexual. We can only watch the way the animal behaves, and where that behavior involves the sexual organs in a sexual way, we have to consider that that activity is sexual behavior.

Prepuberal Sexual Behavior

Sexual behavior in dogs seems to start at a considerable age before puberty. Puppies of either sex, as young as three months of age and sometimes younger, have been noted to mount each other in male copulative fashion and to engage in suggestive sexual movements. Both male and female puppies exhibit the male pattern of adult sexual behavior. It is significant that the female pattern of adult behavior is never exhibited by the female prior to puberty. The reason for this phenomenon has been attributed to the fact that male sex hormones appear in both males and females very early in the puppyhood stage, while female sex hormones do not appear until puberty. But this hormonal explanation is inadequate. While it can, to a certain extent, explain the male pattern of the female puppy, it cannot apply to the male because castrated puppies will behave in a similar manner.

It is generally considered that this activity in prepuberal dogs assumes the nature of play. But why should play in puppies often exhibit this frankly sexual form? The problem of animal play is one that has intrigued many astute investigators. During the last century, Herbert Spencer promulgated the "Surplus Energy Theory of Play," which stated that play was a manifestation of sheer exuberance and a way of dissipating excess energy. The theory broke down because it was well known that animals continued to play long after their exuberance was gone. The exhausted dog will still lope to retrieve a stick that is thrown. The panting cat will still take a final swipe at its catnip toy.

Animals seem to play, not to dissipate excess energy, but simply for the sake of play. Later, an "Instinctive Theory" was postulated, which stated that play was simply instinctive. But this theory also broke down because it could not adequately explain the special forms of activities that were manifested in play. It could not explain sexual play or fighting play or hunting play. The theory currently generally accepted is the so-called "Biological Theory of Play," which states that play is the necessary prelude of prepuberal animals to prepare them to meet the problems of life. Animals do not play because they are young and frolicsome, but rather have a period of youth in order to play. In this period they learn to hunt, fight, protect themselves, and so on. The higher the mental development of the animal, generally speaking, the longer will be its prepuberal period because it simply needs more time to learn the many things that are necessary in order to cope with the problems of life. From this point of view, the frankly sexual play of dogs would seem to be nothing more than a youthful preparation for later requirements in life.


Masturbation rarely if ever occurs in the normal prepuberal or adult female. Of course the female can be stimulated to lick its genitalia where local irritations of the external genitals occur, but this cannot be properly considered a sexual activity. In the male, on the other hand, masturbation occurs rather early in the puppy. It is performed by licking the penis or by rubbing against soft objects that can be conveniently grasped in a sexual embrace. It is rather common in puppies of about five or six months of age, and often continues throughout the adult life. Reliable scientific information regarding masturbation in the dog is notably lacking, though even the most casual observation will reveal its undeniable presence. It is common in males just prior to and upon the completion of copulation. Some dogs, especially those that are bored, left alone a great deal, or those that upon maturity have little opportunity for sexual intercourse, may develop the masturbation habit. Of course masturbation can be encouraged by any pathological factor that will stimulate the excessive flow of sex hormones.

According to my observations, the masturbation habit in the dog is not ordinarily accompanied by outward physical symptoms that are detrimental to the health of the animal. To my knowledge, psychological effects of masturbation in dogs have not been critically examined, though clinical observation seems to indicate that these effects are not especially significant. It is very unlikely, however, that the male masturbating dog conjures up any exciting mental image of the female while engaged in this activity. What is most likely is that masturbation, in this instance, is a purely stimulus-response manifestation. The maturbatory act may be stimulated, for example, simply by licking some penis discharge.

This, in turn, may stimulate the animal sexually and the act is carried through to its completion. The important point is that masturbation in the dog is apparently not consciously directed to sexual self-stimulation. The stimulus that initiates it is only incidental and not necessarily sexual. For the act to be considered genuinely masturbatory, both stimulus and response must be sexual. Where the stimulus is not exclusively sexual—as is the case with the dog—the most that can be said is that we are dealing with a mere masturbatory activity rather than a truly masturbatory act. Nor is masturbation in this sense "abnormal" in the dog. If a dog is properly stimulated it will "masturbate." Thus masturbation is a normal activity in dogs.

Heat Period

The heat period of females was discussed on the page, "Pregnancy and Breeding." However, it will be well to add the less well-known fact that the onset of heat is related somehow to the lengthening of the day. Under experimental conditions, the period when the dog is not in heat can be substantially shortened by subjecting it to abnormal exposures of artificial daylight. Just what specific reaction is involved here is not known, but it is very likely that this fact accounts for the variability of heat periods in dogs in different parts of the world.

Another fact of interest in this connection is that if a cat in heat is not bred, it will remain in heat for several days. If it is bred successfully, it will often lose its responsiveness in about twelve hours.


The act of copulation in cats lasts about five to ten seconds. With dogs, on the other hand, the duration is much longer because genital "locking" occurs. This genital "locking" is quite normal in dogs and after ejaculation the animals will separate without assistance in anywhere from a few minutes to a few hours, with the average time being about twenty minutes.

It may be amusing to note that the longest matings in mammals occur in the mink and sable. These animals do not lock but, once entrance into the female is achieved, it is maintained for very long periods. Several ejaculations seem to take place and there are rest periods in between. From the moment of original insertion until withdrawal, the sable has been timed to copulate for as long as eight hours.

In regard to the frequency of copulation, some male cats may copulate nine or ten times in an hour. Others may copulate four or five times before their sexual responses are subdued. In these instances, each copulation includes an ejaculation. Male dogs, on the other hand, rarely copulate more than once an hour providing copulation is complete and sexual locking occurs. This situation has a logical physiological basis. The cat, after all, must undergo intercourse as a stimulus for the expulsion of the ovum. The female dog expels its ovum naturally without the necessity of any additional stimulation. Thus it is not surprising that the cat copulates more actively than the dog.

Though the upper limit of the responsiveness of the female dog has not been subjected to scientific tests, we can be pretty sure that it exceeds that of the male. When female cats are kept in heat artificially with hormone injections, they copulate continuously and exhaust one male after another.

Another interesting fact is that a pregnant cat will sometimes permit an active male to have intercourse with her. But this behavior is irregular and unpredictable.

Sexual Foreplay

The essential difference between human sexual foreplay and that of the dog is that, unlike the animal, sexual foreplay in the human is consciously directed toward sexual stimulation. A male dog may lick the external sexual organs of a female in heat because it is attracted by the female discharge and its odor, but it does not perform this activity because it feels that it will excite the female. It acts, rather, as if it is merely investigating the area. But the fact is that its behavior does excite the female and excites the male too. In this manner a lusty male can stimulate a sluggish female in heat and achieve a mating. In the same way, a female in heat may sniff at or lick the male organs and may thus excite a sluggish male to become more aggressive in his mating responses. A female may also mount a male in the male copulative fashion and this activity often seems to stimulate the male.

When a male cat is about to have intercourse with a female, the torn first grasps the loose skin of the female's neck in his
teeth. This action seems to have three results: it produces an erection in the male; then the female lowers her fore quarters and gets into the mating position; lastly, by maintaining the grip after it has mounted, the male can more readily get into the proper position so that genital insertion can result. A male cat will rarely succeed in completing the copulatory act unless it grasps the female in this way.

Some dogs may be sexually stimulated merely by being placed in a situation where they had previously experienced intercourse. This is especially true if a breeding crate is used. There can be little doubt that sexual stimulation here is a conditioned response.

Sexual Liaisons

Mateships, as exemplified by human marriage, are considered to be lasting sexual unions. Liaisons are temporary or casual relationships. The best that can be said of the dog is that it is an occasional party to what may be very liberally interpreted as a sexual liaison. This is more the result of circumstances than of preference. One occasionally hears of a male and female brought up in the same household who seem to develop a genuine affection and exclusive sexual preference for each other. But this is the exception rather than the rule. All that can be said for sure is that dogs show a certain amount of discrimination in the choice of sexual partners, and males do so to a greater extent than females.

Sexual Dreams

Not only does every indication point to the fact that dogs dream, but there is further evidence that they also have sexual dreams. Pelvic thrusts with nocturnal emissions have been observed in both male and female dogs and cats. Just how much "imagination" goes into these dreams poses an interesting and challenging psychological problem.
Effect of Spaying and Castration on Sexuality

Spaying promptly and permanently abolishes all sexual behavior in female dogs. These animals possess no attraction for males of their species and never display sexually receptive behavior. The male dog that is castrated before puberty never develops the normal degree of sexual aggressiveness. However, these males do show a certain amount of sexual activity. They may exhibit abortive attempts to mount others and may display a few weak pelvic thrusts. Prepuberally castrated dogs develop nothing more intense than the normal, prepuberal sexual behavior.

The male, castrated in adulthood, however, often shows very little decline in sexual aggressiveness. Laboratory experiments on adult castrated male cats have demonstrated that there is no decline in sexual aggressiveness in these animals over the period of several years during which they were observed. Some of them seemed to suffer a reduction in the ability to copulate, but none were unable to do so. These observations indicate that sexual activity in female cats is much more dependent on hormones than it is in males.

Sexual Inversion and Homosexuality

From the standpoint of endocrinology (the study of hormones and the glands that produce them), no individual is ever totally male or totally female. By definition, a male individual is one in which the male hormones predominate, and a female is one in which the female hormones predominate. It is logical to presume, therefore, that, if some disease process should disrupt this hormonal predominance in either sex, corresponding changes in sexual behavior should occur. Limited though it is, the evidence on hand seems to bear out this contention.

While sexual inversion is rare in male dogs, cases of dogs with cancers of the testicle have been reported in which the affected male seems to undergo a variable degree of feminization, manifesting itself in seeking to be copulated by other males, being indifferent to females in heat, and even becoming an object of sexual desire for normal males. This is the closest approximation to true homosexuality in dogs, that is, to a state in which the sexual drive seems to be clearly directed toward achieving sexual satisfaction with a member of the same sex. One French author believes that these testicular tumors elaborate female hormones or other substances analogous to them that undergo alterations by metabolic processes and terminate in feminization. Still more rarely, feminization is said to come about as a consequence of certain pituitary, adrenal, or thyroid tumors, though specific instances of this casual relationship in dogs have never been brought to my attention.

I am not aware of specific medical cases of the masculinization of female dogs. The cases most often mentioned among animals are those of cows, in which these animals assume a remarkable abundance of the physical and mental attributes of the male. The condition is considered to be caused by various tumors of the ovary or of the adrenal, pituitary, thyroid, or thymus glands, or it may be a manifestation of an excess of male hormones due to a simple functional variation of these several glands. There is no reason why similar cases should not occur in dogs.

As mentioned earlier, normal female dogs exhibit certain distinctly masculine traits in that they often attempt to mount either male or female in the male fashion. Where this occurs before puberty, it has been suggested that it is very likely attributable to the temporary preponderance of male hormone. In mature females, this behavior occurs most commonly during the heat period and seems to be one of the ways in which an aggressive female arouses an unresponsive male to sexual activity.

Male cats, in the absence of a female in heat, will often seek to copulate with each other. However, if a female in heat should come upon the scene, both males will immediately copulate with the female. These activities are normal for mature male cats. So it would seem that male cats are normally bisexual—that is, that they will readily copulate with either male or female, depending upon which is available at the time that the male happens to be aroused.

In regard to homosexuality among otherwise normal dogs or cats, the most that can be said is that while these animals unquestionably engage in homosexual behavior, it cannot be considered true homosexuality because there is no evidence that it is consciously directed to the exclusive attainment of sexual satisfaction in the sense of homosexuality among human beings. A male dog may lick the genitals of another male because of the curiosity aroused by the appearance and smell of an abundant penis discharge. This act may sexually stimulate the dog acted upon, but the act itself seems to be in the nature of an investigation rather than a deliberately sexual move. Male dogs may mount each other in play or even after having been stimulated in the normal fashion by a female. Actual intromission with subsequent orgasm is possible, though most often very unlikely. Females will occasionally lick each other's genitalia, but more as a grooming procedure or out of curiosity than as a sexual approach. The fact that the female acted upon may be stimulated by this procedure is secondary. While the act itself may be classified as a homosexual activity, it does not appear to be homosexually motivated.

The least that may be said, however, is that while true homosexuality does not exist in apparently healthy dogs, some homosexual tendencies exist in all normal dogs, more commonly in the male than in the female. While homosexuality in man may often be attributed to psychological maladjustments, this relationship has not been established in the dog. The explanation of homosexual manifestations in the healthy dog is encompassed within the sphere of its normal activities.

Satyriasis, Nymphomania, Frigidity

Excessive desire for sexual activity in the male is called satyriasis. Excessive desire for sexual activity in the female is called nymphomania. Lack of or subdued sexual desire in either sex is called frigidity. These conditions are more common in the dog than is ordinarily imagined. While the causes of these abnormalities in the human are often psychological in character, there is little likelihood of such a causal relation in the dog, though the involvement of these factors is not impossible. These conditions are most often due to obvious hormonal derangements that are routinely amenable to the pedestrian hormonal and surgical procedures of every veterinarian. It is well to be reminded, however, that, because male sexuality is less affected by hormones than the female, hormonal or surgical approaches will be much less certainly successful against satyriasis than against nymphomania. The frigid animal may be stimulated with appropriate hormones, but attention should also be paid to proper feeding and to cutting down on possibly excessive breeding, which may also be related to frigidity.


We may conclude this section by reminding the reader that, since experimental data regarding these unconventional aspects of the sexual behavior of the dog are notably lacking, it was unavoidable that interpretations of these activities often had to be fragmentary or conjectural. None the less, it seemed a good idea to summarize briefly the present state of our knowledge in this fascinating field. The least that it may accomplish is that it may stimulate more careful observation of the dog's sexual behavior.