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Northwest Notes / THE LABRADOR QUARTERLY - Summer 2011

Diann Sullivan

It's still amazing to me that in my community here almost one hundred miles North of Seattle, how easy it is to run into not only friends when out-and-about, but I see patients of mine from my last practice quite often also (doing infertility nursing).  Even last week, I went inside coffee shop to sip while writing a couple of cards to mail, and thought I recognized a couple from the clinic but couldn't be sure. But on their way out, they stop to say “Hi!”.  Reminds me how the reproductive system is so very amazing and very specific. But one of the true frustrations when first working with a new couple would be after many, many tests, the 'diagnosis' would be “Primary or Unexplained Infertility”.

Primary actually means medically, ' Never has been fertile(even as of yet...).  That may be due to so many things that are just too expensive or impossible to test for or, proven on paper.  Chart notes would be written as , “Unknown and Cannot Be Determined.” Human couples go to a specialist in 'reproductive ' endocrinology (as I worked for) to find the reason for their infertility often after months of not producing pregnancy.   Frustrating to hear for these couples of mine in practice after so much invasive and expensive testing, Unexplained Infertility is the diagnosis for many. For a small percentage of animals in general AND IN DOGS specifically, it may be discovered in times that a dog is simply not fertile. 

In dogs, similar 'reasons' for Primary Infertility exist, and compared to humans, that does exist in animal breeding programs. One explanation is Error in Development (male reproductive parts of the fetuses, as they develop).  Each of the different parts for the developing male fetus has to form correcting in Lutero until puppy is mature enough to birth. The puppy male may be exposed to too little male hormone usually because of metabolism errors, as he develops into a full term puppy.  Infections or inflammation without owner or manager being ware, can lead to many problems. Most of us only think of chromosomal abnormalities in thinking of Downs Syndrome, where a chromosome is not normal or there are too many leading to abnormality.  It is very expensive and almost impossible to test for chromosomal abnormalities for a dog's reproductive system or for the dog in general.  Some sort of abnormal blood flow or abnormal temperature in the scrotum for any length of time can lead to chromosome damage..    And, Primary Infertility can be “genetic” or occurring within a 'family or  a line' of dogs; In my experience, that is really rare as a 'trend'.  Through my many years working with livestock, before my hobby in dogs began, I found that  animals are usually very fertile.

Hormones have VERY POWERFUL affects on our bodies; diabetes is a hormonal disease and an increasing problem for us, existing also in dogs. Growing babies are exposed to different levels of hormones while in Lutero, sometimes much more testosterone and occasionally, to higher levels of feminine hormones. The sex organs, the testicles for the developing reproductive system, are affected by levels of hormone they receive. Sometimes a puppy is born that 'is a male' but seems feminine.  Small ducts or the outward appearance of the scrotum and descended testicles may lack full masculine development if somehow exposed to very high levels of female hormone and not enough testosterone, causing improper development.

We all hear about prostrate problems for men and we are definitely fortunate to live in a time now where testing for prostrate cancer is very, very good.  Most often the prostrate gland slowly becomes enlarged as the dog ages.  This is common as a dog enters old age and yet may not lead to any reproductive problems.  An infected prostrate can be very painful and with any symptoms of obvious discomfort in that area, careful exam by a veterinarian is necessary.  Should the gland simply enlarge and eventually interfere with urinating, the only 'treatment' is to castrate.

We obviously have no influence over male reproductive issues that begin as hormonal or as developmental, but in our lives with our stud dogs, we can take care to protect the dog's external reproductive parts and we can make an effort to learn about what does influence their function as a stud dog.

Trauma or injury can lead to inflammation that can led to fertility problems. Damage inside the scrotum is caused from scarring of connective tissues if they remain inflamed over time. As well, 'sperm-themselves' are meant to be outside the body and considered by-the-body as a foreign cells. Trauma or injury can expose the body's immune system to the sperm itself, causing the body to produce antibodies which will then attack the sperm (cells). Do take care to watch the dog who shows evidence of an injury.

Very rare but also possible in the male dog is the twist of the testicle, or 'Torsion'. This would present or show itself to the dog's care-giver as a sudden swelling and pain and should be considered a veterinary emergency. Without attempt at treatment, blood supply would be cut off and even within a few hours,  damage in sperm producing cells can occur.  

A serious body or systemic (systems), infection with a high fever can certainly affect the making of new sperm. Should fever occur, treat efficiently to reduce body temperature with advice from your veterinarian. Damage from an illness with high fever can lead to sperm count issues that are rarely permanent but apparent for a period of time as healing occurs. This healing may take two to three months to show sperm regeneration and even up to twelve weeks additional for new sperm development and then for the new sperm to mature.

Watch for tumors especially in older dogs.  Any cell can develop into a tumor. Should a tumor develop from cells that produce hormones, the levels in the body usually spike and the testicle will                                                                                stop producing sperm. Tumors can be benign (not cancerous), and others can be typed as malignant or cancer. Cancer of the prostrate gland in dogs is rare but when it is, it is typically cancerous and will spread in the body quickly.

Fascinating that the testicles of the male responsible for making new sperm cells must be cooler than body temperature. We  performed several levels of semen analysis daily at the clinic I worked with and though actual sperm count is important, much more vital to conception is good motility with a high percentage of those 'moving well', moving straight forward or 'rapid and linear'. Not only  is this critical to travel through the cervix to the uterus, but when at the surface of the egg itself, the rapid tail action of the sperm help drive it into the egg for fertilization. Increase of temperature for the testicles does decrease motility of sperm present and will lead to decreased sperm production. In living in conditions where climate is consistently hot, do watch for cool surfaces for dogs to lay on and plan for your dog's environment during hot times of the day.

Whether testicles, penis, prostrate, or prepuce (skins covering the end of the penis), infection is possible from many different bacteria.  Trauma to the tissue covering the end of the penis can be injured causing infections needing treatment with probable antibiotics. Watch for infections for the male externally.  The presence of a cream-looking discharge at the end of the penis is common enough and can be treated with a diluted betadine (Iodine wash), or cleaned for a few days with mild soapy water to clear up whatever is causing the inflammation. After any injury to 'that area', watch any inflammation that can lead to infection.

Truly interesting to me in my constant learning (especially during years nursing with my infertility practice), is to find there are so many 'environmental' influences on sperm count and motility.  Heat, chemicals, antibiotics, injury and infections, ARE 'environmental' influences on fertility, but it is possible for some dogs, when in a new and different environment (standing at stud away from home, show circuits, etc.), to develop stress-related changes in the testicular cells . Thankfully, normal fertility can be seen again within about six months of return to normal 'stresses' or and this is one of those things without real medical explanation.

Our beloved boys can decline in reproductive ability as they age and it is common for dogs oder than ten years to begin to show a decrease in testicle size.  I have written before about my feelings that older stud dogs should have their semen evaluated for count, motility, and any changes yearly after age ten if he is offered at stud. I think anyone standing a dog at stud should check his semen routinely by semen analysis even at the time of perhaps 'fresh A.I.' as well. There is a huge relationship between count and motility and fertility; percentage of sperm that are motile in a 'good count' should be 75% or higher.  AKC does require semen certification for breeding soundness for older dogs now.

I love my boys! (I only had sons... maybe that's a silly reason that I like my (dog) boys so much!) We are blessed that the male reproductive tract has so many less fertility issues versus that of our bitches.   We should and need learn more about what could affect our unneutered males and active stud dogs.

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