Why isn’t my female pregnant?

Why isn’t my female pregnant? What can we do about it?

You did your homework – and had the perfect bitch in her best condition and found the ideal male to mate her to. You know the most common causes of missed breedings are poorly timed breedings and poor semen quality and/or quantity. But you know he had good semen; and her timing, based on progesterone levels (bred 2 to 3 days post-ovulation depending on semen type used), was just right.

And yet, she is not pregnant. Why? And if you try to breed her again, what can you do differently to improve the chances she will carry a litter to term?

First, we need to determine if she conceived and lost the litter, or failed to conceive or achieve fetal placental implantation. If you don’t have her ultrasounded, you won’t know if she conceived or not.  Without an ultrasound to confirm pregnancy (not a relaxin test or palpation – these do not assess for fetal viability), you may have a big piece of the puzzle missing. So when you are trying to justify the decision to do an ultrasound, this is the best reason to do so – this is not the place to scrimp.

If the ultrasound shows no pregnancy, and the semen and timing were good, then causes for failure to conceive or failure for fetuses to implant should be explored.  

These include:

  1. Brucellosis
  2. Herpesvirus
  3. Bacterial infections in the uterus – low grade metritis, not rising to the level of a pyometra
  4. Other bacterial and viral diseases that are not yet well characterized
  5. Failure to complete the ovulation
  6. Failure of the ovary to maintain progesterone high enough to support pregnancy

(hypoluteoidism)

  1. Uterine lining changes that interfere with maintained placental attachment
  2. Genetic incompatibility – fatal genes
  3. Inadequate maternal nutrition
  4. Trauma, stress, anesthesia or drug and hormonal interference
  5. Structural abnormalities causing failure of semen passage to the oviducts including male and female anatomical abnormalities
  6. Hypothyroidism

Diagnostics and history should be used to determine if any of these may have played a role in failure to conceive or maintain the pregnancy up until 4 weeks of pregnancy. Testing may include blood tests for thyroid disease, Brucella, Canine Herpesvirus, progesterone testing, and ultrasound if not already completed. Uterine biopsy and cultures at about 60 days post-ovulation can be useful tools in determining if there are uterine changes that suggest poor uterine lining health. If no underlying cause for failure to conceive is found, surgical breeding may be considered to improve the chances of success at the next breeding.

If the ultrasound shows a pregnancy was achieved but not maintained, this can result in fetal resorption (prior to day 45 of pregnancy) or fetal death and/or abortion (fetal loss after day 45 of pregnancy). This rules out poor timing, poor semen quality, or failure of semen to pass to the oviducts as causes for infertility.

Causes of failure to maintain a pregnancy include:

  1. Brucellosis
  2. Herpesvirus
  3. Bacterial infections in the uterus – low grade metritis, not rising to the level of a pyometra
  4. Other bacterial and viral diseases that are not yet well characterized
  5. Failure of the ovary to maintain progesterone high enough to support pregnancy

(hypoluteoidism)

  1. Uterine lining changes that interfere with maintained placental attachment
  2. Inadequate maternal nutrition
  3. Trauma, stress, anesthesia or drug and hormonal interference

 

A complete history should be taken. Diagnostics should include testing for brucellosis and Canine Herpesvirus. Cultures should be taken and antibiotics used if bacterial disease is suspected. Progesterone levels should be run serially if hypoluteoidism is suspected. The pregnancy can be monitored for viable fetuses with repeated ultrasounds. WhelpwiseTM can be used to manage high risk pregnancies. Progesterone and terbutaline may be indicated if uterine irritability are shown to be putting the pups at risk. If no underlying cause is found, uterine biopsy and cultures at about 60 days post-ovulation can be useful tools in determining if there is a treatable underlying cause and to help with determining a prognosis for future fertility. Treatment for causes suspected or found should be initiated.

Oviduct and Uterine Pathology

If a bitch is bred with quality semen at the appropriate time based on progesterone testing, and is not pregnant based on ultrasound at 4 weeks post-ovulation, AND nothing in her history or on physical examination suggests a cause for her infertility, a surgical breeding at her next cycle or surgically obtained uterine cultures and biopsies should be considered. This is recommended only IF the breeder is committed to achieving a pregnancy. The procedures are invasive, require general anesthesia and cannot be combined. Surgical breeding may lead to a pregnancy. Surgical biopsy,may provide a prognosis and diagnosis. If surgical breeding with good semen and good timing is unsuccessful, surgical biopsy at the end of diestrus should be done to determine the cause. The decision is made by the client in consultation with the veterinarian and is influenced by the age of the bitch, availability of high quality but replenishable semen, previous attempts to breed, and the way that the client makes decisions.

There are no practical procedures for detecting or treating oviduct patency in dogs. Scar tissue or inflammation may obstruct the oviduct, preventing fertilization and passage of the fertilized ova into the uterus. Endometritis, inflammation of the uterus, does not allow for implantation and fetal development. Cystic endometrial hyperplasia, if advanced enough, does not allow adequate surface area for implantation and fetal development to occur. Although these conditions can be diagnosed by uterine biopsy, the changes cannot be reversed with treatments available at this time. Sometimes the biopsy results are only helpful for prognosis. The endometrial changes may be so severe that pregnancy is impossible and the best option is to stop trying. Sometimes the changes are reversible, and sometimes the prognosis is good because there is no pathology.

Uterine biopsy for histopathology and culture (aerobic, anaerobic, and mycoplasma/ureaplasma) can provide invaluable information. Infectious endometritis is a treatable cause of infertility. Some bitches have become pregnant on the subsequent estrous cycle using appropriately selected antibiotics. Uterine biopsy should NOT be attempted at the same time as a surgical breeding because of the associated inflammation. If a metropathy is suspected or confirmed at c-section, uterine biopsy, molecular pathology, and culture with histopathology and placental histopathology can be a useful service to offer the client.

The ideal time for uterine biopsies is near the time the bitch would whelp, 60 days after ovulation, if she is pregnant. This is the time of maximal progesterone influence, which should produce the greatest pathological changes in the uterus.

Courtesy of Dr Marty Greer of Veterinary Village, Lomira WI

Controlling When Your Bitch Comes into Season

Technology advances again and has now allowed us to either delay or induce estrous (heat) cycles in bitches with more ease and accuracy than ever before.   OvuplantR (Deslorelin) is a hormone contained in a pellet. It is labeled for use only in horses. This pellet is inserted under the mucosa of the vulva. For this product to be effective in inducing estrous, the bitch MUST have a progesterone level of less than 1.0 ng/dl immediately prior to insertion of the drug pellet or it may block, not induce estrous.

Typically with the OvuplantR , the patient will come into heat within 3 to 7 days, and be ready to breed 8 to 10 days after she comes into season (11 to 17 days after insertion). The implanted drug pellet MUST be removed to maintain pregnancy. This is a prescription drug and must be inserted and removed by a veterinarian. Approximately 90% of the time, the use of this product allows you to have control over the time you breed. This can be valuable for bringing bitches into heat for travel, specialties, to avoid scheduling conflicts in your personal life, or to produce puppies when you need them, such as for futurities.   Please return for removal of the Ovuplant after breeding is completed.

Cabergoline (DostinexR) is a similar product, given orally. Approximately 70% of bitches taking the product will start estrous within 10 to 30 days of starting the drug. This is dosed at 5 mcg/kg once daily for 10 days. In small bitches, compounding may be necessary to scale the dose down.

Contact us for more information on how this new therapy permits you to time your bitch’s breedings and whelping to fit your needs!

Canine Mycoplasma and its Role in Reproductive Disease

Mycoplasma infections have been implicated as a cause of infertility in both bitches and stud dogs. As a result, mycoplasma continues to receive attention as a potential concern for purebred dog breeders. This article discusses what is currently known about canine mycoplasma infections and outlines a management approach for breeding animals.

What is mycoplasma?

Mycoplasmas are bacterial organisms that, because of their extremely small size, have been placed in a separate class. Also, unlike any other bacteria, mycoplasmas lack a rigid cell wall which makes them unaffected by antibiotics that act by invoking cell wall damage (for example, penicillin). Mycoplasmas are extremely fastidious organisms that are difficult to culture without special media, and even then may be difficult to recover. Ureaplasmas are a distinct type of mycoplasmas that have been sub classed and are identified by their own name.

Mycoplasma as part of the normal flora:

Several mycoplasma species have been found to be normal inhabitants of the upper respiratory and genital tracts of dogs and cats, and as a result they can be routinely isolated from oral, nasal, conjunctival and genital mucous membranes. Several studies have specifically looked at the frequency of mycoplasma recovery from the genital tracts of fertile versus infertile bitches and stud dogs, and no significant difference has been found. Therefore, recovery of mycoplasma from a vaginal or semen culture does not always correlate to reproductive disease, and likewise does not always need to be treated. Since these organisms exist in the respiratory tract as well as the reproductive tract, aerosol transmission from dog to dog (airborne, licking, sniffing, etc.) is probably more frequent than venereal transmission.

When to worry about mycoplasma?

While mycoplasmas may be normal inhabitants of the reproductive tract, they have been associated with infertility, lesions of the reproductive tract and sperm abnormalities. As with many opportunistic pathogens (organisms that may cause disease but frequently don’t), clinical disease often results when an animal is under stress and/or exposed to high numbers of organisms. Close, intensive breeding conditions (as in a large kennel or at indoor dog shows) provide the opportunity for high numbers of organisms to develop. A healthy dog or bitch especially if housed individually, however, may not become diseased even after known exposure to the organism.

It has been found that the administration of broad spectrum antibiotics may suppress many other bacteria that make up normal flora and allow mycoplasmas to overgrow. Therefore, the prophylactic use of antibiotics pre breeding is not recommended as it may actually create a pathogenic state, and may contribute to the development of antibiotic-resistant populations of organisms.

A mycoplasma culture should be performed if:

  1. A dog has missed several bitches (no conception)
  2. A semen evaluation shows morphologically abnormal sperm cells.
  3. A bitch has not conceived having been bred to a fertile stud dog on appropriate days.
  4. A dog of bitch produces conception but has a documented high rate of fetal resorption.

It is important to remember that there are many other causes of the above problems, and so a mycoplasma culture should be only one part of a thorough diagnostic investigation performed by a veterinarian experienced in canine reproduction.

Proper Mycoplasma Culture Technique:

Due to their fastidious nature, mycoplasmas require special techniques for successful growth in cultures. As a result, mycoplasma cultures should only be sent to laboratories competent in the recovery of the organism. It is recommended that ureaplasma is cultured for at the same time, since it is a similar organism and has also been implicated in infections of the reproductive tract.

Proper technique in obtaining the sample to be cultured is also extremely important. In bitches, it is recommended that the vaginal area close to the cervix be sampled using a guarded swab. In stud dogs, it is important that a semen specimen be collected using sterile technique, avoiding urethral contaminants.

What to do about normal fertile dogs and bitches?

Since mycoplasma is frequently cultured from the vagina of normal fertile bitches, routine pre breeding cultures of bitches are not warranted. Since mycoplasma is frequently recovered from culture of the prepuce and/or semen of normal fertile males, routine pre-breeding cultures may show some growth of mycoplasma as part of the normal flora. However, some owners may choose to periodically have a dog’s semen culture for mycoplasma. While a negative result is definitive, the significance of a positive result must always be determined by correlation to semen evaluation and clinical condition. Unfortunately, a dog’s fertility status cannot be determined on the basis of mycoplasma recovery.

Summary:

            Mycoplasma infection is only one of many factors that may impact canine fertility. Working with an experienced veterinarian with a thorough, systematic approach to investigating fertility problems will pay dividends to your breeding program.

Approach to Infertility in the Bitch and in the Dog

WORLD SMALL ANIMAL VETERINARY ASSOCIATION WORLD CONGRESS PROCEEDINGS, 2007

  1. Fontbonne, DVM, MSc, DECAR

Ass. Pr., Animal Reproduction–Alfort National Veterinary College (Paris)

Cedex, France

In comparison to the last 10 or 20 years, veterinarians are now frequently requested to solve fertility problems in the dog, mainly due to the increased popularity of purebred dogs as well as for sentimental or financial reasons. In fact, breeders may be concerned about different kinds of problems which include but are not limited to true infertility (their bitches produce no pups after mating or Artificial Insemination), anoestrus or a low prolificacy rate.

Many different problems can lead to infertility including hormonal problems, infectious diseases, congenital or acquired defects of the genital tract. We recommend that veterinarians follow a very strict progression, commencing with the most frequent cause to the most uncommon cause. In the bitch, things become even more difficult when we realize that apparent infertility can be due to very different situations which prove difficult to distinguish, such as lack of fertilization (no union between eggs and sperm) and early embryonic death.

  1. 1. In the Bitch

1.1 Mistimed Breeding or Artificial Insemination

According to the vast majority of scientific publications, mistimed breeding represents by far the most common cause of infertility in the bitch. This is why a veterinarian willing to solve fertility problems in the bitch has first to be skilled in timing ovulation in the bitch.

Apart from progesterone assays, ovarian ultrasonography is especially indicated in infertile bitches, as it represents the most accurate way to determine the precise date of ovulation.

1.2 Infertility with Prolonged Interoestrous Intervals

The apparent prolongation of interestrous intervals occurs in dogs with a silent heat, defined as ovarian activity in the absence of overt physical and behavioral changes characteristic of canine estrus.

Among the hormonal causes of anoestrus we find hypothyroidism, hyperadrenocorticism, hyperprolactinemia, or bitches treated with hormonal compounds such as progestagens, androgens (racing dogs) or anabolic steroid compounds. Ovarian cysts that secrete progesterone may cause prolonged interestrous intervals.

Bitches housed in very bad environmental conditions (including a high concentration of animals, low luminosity, low quality food) may undergo prolonged interestrous intervals.

1.3 Infertility with Shortened Interoestrous Intervals

This type of infertility may be divided into two major causes: bitches suffering from ovarian hyperstimulation (mainly follicular cysts or Granulosa cells tumor), and/or bitches showing a premature decline in progesterone during diestrus.

1.3.1 Ovarian Cysts or Tumors

It is important to diagnose and remove these hormonally active cysts or tumors as quickly as possible for at least two reasons. First, it is necessary to cure them and try to restore fertility. Second , the secretion of high quantity of estrogens may act on the uterus as a potential factor towards the cystic endometrial hyperplasia–pyometra complex, but also on the bone marrow in creating progressive non regenerative anemia.

Follicular cysts may be single or multiple; if multiple cysts are present in one ovary, the cysts do not communicate. The ovarian cysts in the bitch may be present in only one or both ovaries. When possible, it is much more valuable to perform ovarian ultrasonography.

Some authors recommend induction of luteinization of the cystic follicles, using GnRH or hCG. We personally do not recommend such protocols, as they increase the progesterone plasma level after a prolonged period of estrogen secretion. Based upon our clinical experience, this treatment very often leads to the occurrence of pyometra in the following weeks. Surgical removal of a cyst, or aspiration of a cyst with a fine sterile needle under laparotomy or ultrasonography may be new alternatives in therapy.

Granulosa cells produce estrogens; and therefore, it is not surprising that GCTumours often lead to infertility with prolonged heat periods.

1.3.2 Premature Decline in Progesterone

Split heats are defined as successive short proestrus signs, at intervals of 2 weeks to 2 months, associated with short interestrous intervals. This pattern is more often observed in young bitches and leads to no real infertility in the rest of the genital life of the bitch.

Anovulatory cycles are not frequent in bitches. In such anovulatory cycles, serum progesterone level never increases above 3.5 to 6 ng/ml. This explains why the following heat period will often occur earlier than usual.

Bitches may also suffer from hypoluteoidism, which is the lack of progesterone secretion during pregnancy which makes the pregnancy impossible to maintain. Some breeds are well known to express hypoluteoidism, like Rottweilers and German Shepherds. Progesterone supply can be given parentally (progesterone in oil: 2 mg/kg every 3 days; ally-trenbolone … ).

In France, veterinarians often use oral micronised progesterone which is currently given to women.

1.4 Infertility with Normal or Sub-normal Interoestrous Intervals

1.4.1 Hormonal Problems

Hormonal defects may be suspected also in bitches with regular interestrous intervals, and veterinarians should control the hormonal status of the bitch during the heat period and also during pregnancy.

1.4.2 Infectious Diseases

Several viruses have been shown to playa potential role in canine infertility.

Several elements suggest that Canine Herpes Virus (CHV) may well act on infertility in the bitch. Recently, some papers have pointed out the potential incidence of a parvovirus Minute Virus of Canines (CPV1) on resorption during the first half of pregnancy.

The incidence of bacterial infections on canine infertility is better documented. Canine Brucellosis could generate early embryonic or fetal death through endometritis.

Other specific bacterial diseases have been suspected to act on canine infertility.  However, usual genital bacteria may playa real role on infertility. Canine Mycoplasmas and Ureaplasmas are commonly isolated in the genital tract of fertile and infertile bitches. But it has been shown that there is a higher incidence of these agents in the vagina of infertile bitches.

Many bacteria are commonly isolated from the uterus and the vagina of normal fertile bitches. Several studies barely demonstrate any difference in the composition of the vaginal flora between fertile and infertile bitches. But it has been shown that in case of vaginitis, there are significant qualitative and quantitative variations. Strong evidence exists that bacteria causing vaginitis may lead to infertility. It may well have been underestimated due to lack of specific clinical signs and due to the difficulty of the clinical examination of the vagina of the bitch.

1.4.3 Drug-Induced Infertility

In practice, many breeding bitches may be treated with drugs that may contribute to the decline of fertility. Steroid hormones and anti-fungal compounds may create hormonal defects in pre-puberal or adult bitches. Abortive drugs such as prostaglandins, antiprogestins and antiprolactinic substances have to be avoided during pregnancy.

1.4.4 Anatomical Abnormalities of the Genital Tract

Some bitches do not manage to mate because of congenital or acquired abnormalities of the posterior genital tract (vulva, vestibule or vagina).

Acquired diseases or abnormalities of the posterior genital tact (scars after a bad

parturition, episiotomy, violent mating … ) may also lead to the lack of copulation.

1.4.5 Uterine Pathology

Endometritis is a common cause of infertility in mares. In bitches, however, it is hard to diagnose. Endometrial cytology, eventually performed after endoscopic cannulation of the cervix, may be valuable.

Bitches with cystic endometrial hyperplasia (CEH) are often infertile due to implantation failure after conception. Somehow, ultrasonography usually permits the visualization of the glandular endometrium.

1.4.6 Abnormal Sexual Behaviour

Many psychological factors may influence sexual receptivity in bitches. Some authors think that psychology may influence factors like ovulation or early embryonic death in the bitch.

1.4.7 Miscellaneous Causes

Bitches with systemic diseases like diabetes mellitus, hyperadrenocorticism or renal insufficiency may likely be infertile.

Finally, breeders stress nutrition when their breeding kennel suffers from decreased reproductive results. Little is known in this regard.

  1. 2. Male Infertility

After mistimed breeding, male infertility may well be the most common cause of conception failure in bitches presented with infertility.

Very little is known about male infertility in the dog. Regarding human male infertility, the cause remains unknown in 70% to 74 % of cases. In the area of human medicine, when the semen is of poor quality, most of the time assisted reproduction techniques are utilized such as in vitro Fertilization (IVF) or Intra-Cytoplasmic Sperm Injection (ICSI). These techniques are not routinely available to the dog; therefore, the prognosis of infertility often remains very poor. However, some infertility causes can be partially or totally cured if the veterinarian is consulted early enough. But in only 10% of dogs presented with infertility may fertility be restored after diagnosis and appropriate treatment.

Veterinarians willing to diagnose and attempt to cure male infertility must be completely knowledgeable about the investigation of the male reproductive function and especially the method of performing the sperm collection and analysis (spermiogram).

2.1 Prostatic Problems

A prostatic problem often plays a direct role in decreasing fertility. The prostate is the only accessory gland present in the dog , as no seminal vesicles exist. Chronic prostatitis has been shown to be a rather common cause of infertility in dog. It is often suspected when a dog brought for semen collection for Artificial Insemination or freezing of the semen suffers from hematospermia, especially in the 3rd fraction of the ejaculate.

In case of hematospermia, when suspecting an infectious prostatitis, Levy et al.(2006) showed that bacterial examination after an ultrasound-guided biopsy seems the only reliable diagnosis technique, much more than semen culture.

When treating prostatic problems in the dog, the use of common anti-androgenic compounds may definitively alter the quality of semen and subsequent fertility. That is why many reports have been made about the use of 5 a reductase inhibitors (finasteride). Finasteride is a 4-azasteroid synthetic drug that inhibits 5a-dihydroreductase, an enzyme that is responsible for the metabolism of testosterone to dihydrotestosterone in the prostate, liver and skin.

Recently, some new anti-androgenic drugs (osaterone acetate) seemed to decrease the size of the canine prostate without altering spermatogenesis and may be potentially used in breeding dogs (Mimouni et al. 2006).

2.2 Infectious Diseases

Infectious diseases probably represent a major cause of infertility in male dogs living in breeding kennels. Germs can cause prostatitis, which may alter the biochemical composition of prostatic fluids and may induce a permanent or temporary blockage of the ducts as they enter the prostate. But infections often lead to an orchitis/epididymitis, with a subsequent alteration of the quality of the semen. Canine Brucellosis infection in males have been well described and any male dog suffering from infertility with a bad spermiogram should be serologically tested for this disease. Recently also, the interest of leukocytes quantification in the ejaculate has been further studied (Martin 2005).

2.3 Hormonal Dysfunctions

Central hormonal causes are not well documented. Testicular tumors which are responsible for excessive hormonal secretion (Sertoli cells tumors, Leydig cells tumors) may cause a decrease of spermatogenesis, even when these tumors are located only in one testicle and still quite small in size. Hypothyroidism is often stated as a potential cause of infertility. The link between hypothyroidism and low quality semen is still unclear and probably very much overestimated .

2.4 Retrograde Ejaculation

Retrograde ejaculation consists of a retrograde backflow of semen into the bladder when ejaculation occurs. This leads to either aspermia or oligospermia. In dogs, retrograde ejaculation is not well documented. This problem does not seem to be permanent. Treatment of retrograde ejaculation has been better documented recently (Romagnoli 2004, Beaufayset a/2004). Treatment may be attempted by collecting semen when the bladder is full (which makes the sphincter close more firmly). Sympathomimetic drugs like phenylpropanolamine (3 to 4 mg/kg per os twice daily) or pseudoephedrine (4 to 5 mg/kg per os three times daily or 1 to 3 hours before semen collection or attempted breeding) may be tried.

SPEAKER INFORMATION

Alain Fontbonne, DVM, MSc,

France

URL: http://www.vin.com/doci?id-3860829 (http://www.vin .com/doci?id-3860829l

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