Tag Archives: Interestrous

Causes of Infertility and Puppy Deaths

Photo by Bob Segal

It seems like it should be so easy, creating a gorgeous litter of Gordon Setter puppies. But, as many experienced breeders will tell you, it’s not simple, and sometimes our dream of those future winners and fabulous family pets becomes nothing more than wishful thinking as the reality of a failed breeding hits home. When this reality becomes the norm rather than a one time event, breeders often seek the advice of canine reproductive experts to help unravel the mystery. Having some knowledge and a basic understanding of what can and does go wrong with our bitch during breeding is imperative for the serious breeder.

So let’s spend some time talking about what could be amiss with our bitch by starting with the assumption that our male was fertile and the sperm quality was near perfection. In the bitch we learn that finding a cause may be very difficult as there can be many different situations that are very hard to determine, for example being able to tell if the eggs were actually fertilized by the sperm or if instead there was early death of the embryos.  We’re going to explore the causes of infertility in the bitch in general terms to give you an idea of what your reproductive expert may find.

Mistimed Breeding

The majority of missed breedings are due to mistimed matings. We now have many fantastic tools at our disposal to tell us the optimal time to breed our bitch, which means that by working with a veterinarian who is knowledgeable about canine reproduction we can confidently eliminate this as an issue early on in the game. To determine the proper timing of the breeding we can employ techniques like vaginal cytology, endoscopic appearance of vaginal folds and progesterone testing which are the most commonly used and accurate methods.

  • Photo by Bob Segal
    Photo by Bob Segal

    Ovarian Ultrasonography is the most accurate method to determine the precise ovulation date and can help to develop the number of growing follicules as well as the follicules that are undergoing ovulation thus assisting in the complete evaluation of the fertility of the bitch. You will find photos and an explanation of this procedure in the article Ovarian Ultrasonography and Follow up of Estrus in the Bitches.

Infertility and Prolonged Interestrous Intervals

The interestrous (simply put this is time in between the seasons) is normally between 4 and 13 months with 7 months being the average. There are many variations in the interestrus time period and this may not be abnormal, however, once the heat cycle is established, most bitches will maintain a fairly consistent cycle throughout their lives varying little from year to year, cycle to cycle. Prolonged interestrous in the bitch may cause infertility and can be caused by:

  • The silent heat occurs when ovarian activity takes place within the bitch without the outward appearance of the physical and behavioral changes that are characteristic of a bitch in season.
  • Hypothyroidism – the 2004 GSCA Health Survey reported an 8% incidence of Hypothyroid in our breed. Your vet will recommend a thyroid panel when addressing any fertility issue and you should ask for this even if the cycle of the bitch is normal and not prolonged. I found a reference chart sharing the ideal thyroid levels for breeding bitches and have included that information for your review along with a link to the article John Cargill on Thyroid. …”following the guidance of , Dr. Priscilla Stockner, MS, MBA DVM, Veterinary Management Services/Canine Cryobank and W. Jean Dodds, Director, Veterinary Hematology Laboratory, New York State Department of Health…The Normal ranges and Ideals for breeding  purposes are as follows:”
Test Normal Ideal
TT4 22-54 >38
TT3 1.2-3.1 >2.2
FT4 12-39 >25
FT3 2.2-4.8 >3.5
T4A <25 <10
T3A <10 <5
  • Other hormonal diseases such as Hyperadrenocorticism (Cushings Disease) or Hyperprolactinem
  • Bitches treated with hormonal compounds such as progestogens, androgens (racing dogs) or anabolic steroid
  • Ovarian cysts that secrete progesterone.
  • Environmental – A final cause of the prolonged cycle could be found in bitches who are housed in very bad conditions such as in high numbers or overcrowded. Those with limited or no access to sun or day light or housed in very low lighting, bitches fed a low quality food and similar restrictive conditions.

Infertility and Shortened Interestrous

  • Follicular cysts or Granulosa cells tumor causing over stimulation of the ovaries. There are various treatments for these issues that may return your Gordon Setter to fertility.
  • A premature decline in progesterone during diestrus causing an inability to carry the pregnancy to term. Early embryonic or fetal death is nearly impossible to detect and may be caused by endometritis, cystic endometrial hyperplasia and embryonic defects or possibly inbreeding. These deaths are often associated with a drop in the blood progesterone level.
Photo by Bob Segal

Infertility due to Infectious Diseases

  • Canine Herpes Virus (CHV) – causes fatal infections in newborn puppies and vaginitis in the bitch. It can cross the  placenta and infect puppies resulting in fetal death, mummification, abortion, premature birth or the delivery of weak, nonviable pups. Exposure to CHV is very common and generally results in few if any symptoms for the adult. As a virus however, it does go dormant in the dog and may flare during times of stress such as pregnancy. It is very important for all breeders to realize the complexity and the severity of this virus as it relates to pregnancy, fetal health and newborn puppies. There are several excellent sites hosting articles relating to CHV infection and I am providing you a link to click for Stress, Infertility and Herpes Infection by Mary C. Wakeman DVM, Ashford Animal Clinic and Canine Fertility Center.
  • Canine Distemper Virus – may cause spontaneous abortion from the stress of the disease with or without infection of the fetus.
  • Canine Brucellosis – The most common bacterial cause of abortion in bitches occurring between 45-55 days. Infertility generally follows the infection, vaginal discharges and aborted fetus tissues are highly infectious and extreme care should be taken to prevent transmission to other dogs and bitches.
  • Specified bacterial diseases such as E. Coli, S. aureus, and Strep are suspected in the case of infertility. B-hemolytic Streptococcus has been reported in fetal infection resulting in the abortion of the puppies or the birth of weak non-viable puppies. Several studies have given indication of some slight difference in the composition of the vaginal flora between fertile and infertile bitches, however it has been shown that with the presence of vaginitis there are significant variations in that flora and strong evidence that the bacteria causing the vaginitis may lead to infertility. It is considered possible that the role of vaginal bacterial as it concerns infertility may be underestimated as it lacks clinical signs and is difficult to determine under normal clinical examination of the vaginal tract. These bacteria are frequently cultured from vaginal discharges or fetal tissues after abortion and may be associated not only with infertility but also persistent vaginal discharge and repeat abortion especially in older bitches.
  • Parasitic infections can cause of infertility.
  • Mycoplasma and Ureaplasma – these are opportunistic organisms that are normally found in the vaginal canal, however heavy infections may cause infertility, early embryonic death, resorption, abortion, stillbirths or the birth of weak and nonviable puppies.
  • Neospora Caninum – may cause early fetal death. Neospora are protozoan parasites also infecting wolves, coyotes, dingos and other wild dogs. Dogs may become infected by eating infected cattle, deer, chickens (especially barnyard chickens), or any of a variety of wild animals. Infections may be transmitted through raw meat diets. Once infected the dam may pass the infection to the litter and should they survive birth, some puppies may develop progressive hind-limb weakness and muscle atrophy. Adult dogs may show symptoms of inflammation of the brain and/or spinal cord, nodules or ulcers on skin or mouth, pneumonia, or myocarditis. A Neospora infection can also be present with no signs or symptoms in the host.
  • Toxoplasma gondii – Another protozoal parasite that may cause mild disease in adult dogs but most commonly persists as an unrecognized infection causing few if any symptoms. T. gondii when present may cause fetal infection and death or abortion and, if the puppies survive birth, it should be noted that T. gondii has been found in the milk of lactating bitches. T. gondii is most commonly passed through the fecal matter of cats who are the primary host.

Other causes of Infertility include:

  • Drugs and induced infertility –  steroid hormones or anti-fungal drugs may create hormonal defects in bitches. Obviously, one would want to avoid abortive drugs such as prostglandinsm, antiprogestins and antiprolactinic substances during pregnancy.
  • Anatomical abnormalities of the vulva, vagina, vestibule may prevent a natural breeding for a bitch. These could be congenital or acquired diseases of the genital tract like scar tissue.
  • Endometritis – difficult to diagnose in the bitch this is a common cause of infertility in horses. An Endoscopic canulation to obtain cervical smear may be the best option to identify this disease.
  • Cystic endometrial hyperplasia (CEH) prevents implantation after conception and often leads to pyometra. There is a successful therapy to treat CEH and it may be identified by skilled ultrasound.
 Links to additional reference material:

Now you all should know I’m not a medical expert, nor am I a veterinarian, so what appears here is my layman’s interpretation from research I conducted in order to write this article for you. I do hope that those who are experts will let us know if there are errors or additional information that should be included here by leaving comments or sending me an email at gordonsetterexpert@gmail.com. Additionally, we encourage everyone to share their thoughts, questions, experience or knowledge with our readers by adding comments.

The Estrous Cycle and Fertile Period