Welcome to this second, more organize page about reproduction in pets.
On this Page:
Undescended Testicles (Cryptorchids)
Every once in a while a male puppy will have only one testicle in the scrotal sac instead of the normal two. Or none.
In the normal pup, the testicles develop in the abdominal cavity but within a few months (usually just days) they descend through the inguinal opening and make their way into the scrotal sac.
This is more common in toy breeds and is an inherited trait. For this reason alone, we encourage castration; to prevent this trait from being passed on. But there’s another reason: Dogs with an undescended testicle are much more likely to develop future testicular cancer.
The only problem with castrating these guys, though, is sometimes we can’t easily find or get to the undescended testicle... at least not without making an incision into the inguinal ring and going into the abdominal cavity ... a much more involved surgery than the typical castration.
Here’s the deal:
If you don’t do anything at all, you may luck out and the second testicle will eventually come out. This is a reasonable approach for pups up to 6 months of age, but after that, forget it. You risk both future testicular cancer and passing the problem along to future generations.
If you castrate the descended testicle, but leave the undescended one ... usually because your vet couldn’t find it without doing major abdominal surgery...it’s safe to assume that the undescended testicle will be sterile, but it may very well produce testosterone and all the behavioral problems that goes with it. And again, there’s a higher chance of future testicular cancer if an active testicle is left in the warm environment of the abdomen.
Sometimes the undescended testicle is not active ...apparently it just never developed much... and there’s no problem with leaving it alone. One way to tell is to wait until after puberty and see what happens. If your pet starts lifting it’s leg and marking every tree and so forth, despite having had it’s one exposed testicle castrated, then it’s a good bet there’s an active testicle in the abdomen and you should consider surgical removal despite your frustration in “having to pay for the same surgery twice”! I guess you have to expect imperfections in life...I know my wife does.
In any event, your vet will give you several choices, but in general, it’s best to get the job done, despite needing more extensive surgery, to prevent future problems.
Birth Control Alternatives
TEXTBOOK OF VETERINARY INTERNAL MEDICINE
Client Information Series; written by Dr Autumn P. Davidson
Neutering, ovariohysterectomy (spaying) of females or castration of males, remains the most effective, least expen-sive, safest, and permanent method of birth control for pets. The procedures are well tolerated by dogs and cats and are routinely performed in most veterinary hospitals, and both dogs and cats can have the surgery as young as 6 to 8 weeks of age.
The only valid reason to avoid neutering as a birth control method is that the pet has value as a breeding animal. A valuable breeding animal has desirable physical and behav-ioral traits for its (pure) breed. This animal should have undergone appropriate testing and found not to have evi-dence of any known genetic defects. In addition, the owner of that pet must be willing and able to take responsibility for managing breeding, whelping or queening, weaning, so-cializing, and placing the offspring produced. Breeding dogs and cats is not a financially rewarding undertaking-much the opposite! Financial setbacks are common, raising pup-pies and kittens can be quite time consuming, and finding desirable homes for the offspring is a major responsibility.
The pet overpopulation problem is a gigantic and serious reality in the United States that underscores the need for responsible breeding. Breeding animals should be neutered for health reasons when their reproductive careers are com-plete. Neutered animals have the same capacity to perform as hunting, herding, and guard animals. Breast cancer is at least as common in dogs and cats as in people, and spaying a female before her first "heat" virtually eliminates risk of breast cancer in dogs and cats. Spaying between the first and second cycles dramatically decreases the risk of breast cancer. Obviously, spaying also eliminates risk of diseases of the ovaries or uterus, which are relatively common. Pros-tate and testicular diseases are also common, and neutering of males decreases the risk of these problems as well. Neut-ered animals should be fed approximately 25 per cent fewer calories to prevent obesity; otherwise, their physique remains normal. Urinary incontinence occasionally occurs in spayed female dogs. This condition is treatable.
Alternatives to neutering for temporary birth control in pets are few. Most products available in the United States are not licensed for use in pets or are not recommended for pets intended for breeding. None have current application to the male. Birth control in females is accomplished by pre-venting estrous cycles or interrupting pregnancy establish-ment. Estrous cycles can be prevented in bitches or queens by appropriate administration of commercially available veterinary progestin or testosterone compounds. Progestin compounds work to prevent estrous cycles by keeping the female in a "pregnant-like" condition. Unfortunately, the administration of progesterone to an intact (unspayed) bitch or queen can cause uterine wall disease, leading to the later development of a severe and potentially life-threatening uterine infection called "pyometra" or infertility. Progesterone medications can also cause or contribute to the development of serious diseases (diabetes, growth hormone disorders) and anatomic problems (mammary masses, gallbladder disorders). Therefore, we do not recommend the use of progestogens to prevent estrous cycles. Testosterone-like compounds prevent estrous cycles in bitches by keeping the female in an anestrus-like (no ovarian activity) condition. Behavioral side effects (aggression), tearing of the eyes, malodorous skin, liver problems, and sub-fertility during subsequent estrous cycles are common consequences of the use of testosterone compounds. Clearly, these are not ideal compounds for use in valuable breeding animals.
Methods for preventing estrous cycles by administering synthetic hormones with fewer side effects or immunizing the animal against egg membranes or endogenous hormones have not been perfected to the point where they are commer-cially available. Methods for preventing pregnancy by interfering with egg travel in the fallopian tubes or embryo implantation in the uterus with estrogen compounds are not recommended because of their potential for causing life- threatening bone marrow suppression (the bone marrow is the sole source of red and white blood cells and cells that help clotting, called platelets). Estrogens may also promote later development of pyometra, clearly undesirable in an animal intended for breeding. Application of newer human birth control agents, such as carbergoline and mifepristone, in pets is limited by availability in the United States, but these agents have the best promise for providing effective birth control with minimal side effects.
The best current nonpermanent method for preventing pregnancy in the bitch or queen is simply to prevent breeding (copulation) by confining the individual indoors, away from intact (un-neutered) males. Bitches should be let into an enclosed yard only with direct supervision or on leash for the entire time when copulation could occur. This could be as long as 3 weeks. A veterinarian can determine when the bitch's cycle is complete by performing vaginal cytology. Queens must be kept isolated from toms during their entire period of receptivity, as they ovulate after copulation.
More Articles About Other Methods of Neutering and Spaying
Currently, researchers are trying to develop injectible forms of immunocontraceptives, or contraceptive vaccines, that will prevent pregnancy. In a few years, researchers hope to have a sterilization vaccine that will be safe and reliable, not to mention FDA-approved.
Several different companies and universities are working on their own variations of this concept; all are still in the research or development stages. Some organizations are working on a one-time, permanent vaccine, while others are looking into a method that would result in temporary infertility. Some vaccinations would be for females, others for males; some are concentrating on dogs, while others are working on a feline vaccine.
A number of these injections use porcine zona pellucida (PZP) which is the membrane surrounding female pig eggs. All female mammals have a similar coating on their eggs, which allows the sperm to fertilize the eggs. "When you inject it into the animal, the animal produces antibodies against the PZP," explained Irwin Liu, a professor in the University of California at Davis College of Veterinary Medicine's Department of Population Health and Reproduction. The PZP is not exactly the same as the animal's own egg membrane, but has common properties and so the antibodies bind to the egg, blocking any sperm.
Dr. Liu is currently working on a vaccine that will chemically sterilize dogs. He estimates it will be approximately five to 10 years until the vaccine is ready for commercial use. Right now it is being tested on dogs.
The vaccine is a variation of another PZP vaccine he has already developed for female horses. This injection has been used successfully in wild horses by the U.S. Bureau of Land Management.
There hasn't been as much research on sterilizing cats, he said, mostly due to a lack of interest. For some reason, he said it seems that more money is available for canine research. Nevertheless, he hopes the vaccine will eventually be available in a feline form as well. The shot would be great for controlling both feral cat and dog populations, he said. It might even be good for wild rats and other pests, he added.
Another vaccine designed for female cats is being developed by microbiologist Dr. Stephen Boyle and theriogenologist Dr. Beverly Purswell at the Virginia-Maryland Regional College of Veterinary Medicine. This oral vaccine does use PZP but is delivered in genetically engineered bacteria that is placed in a food bait left out for feral cats.
Currently, they are trying to make the vaccine specialized to cats so that any other animal that ate the bait would not be unintentionally sterilized.
Neutersol (Note: now approved and available)
Neutersol is a shot that is injected into the scrotum of male dogs and ceases sperm production. It. is not yet approved, but it could be useful to control overpopulation of dogs.
Even when and if permanent sterilization alternatives become available to the public, surgery may still be the best choice, said Dr. Deborah Beck-Ross, a small animal veterinarian in West Grove, Penn, who has been following these recent developments. "There are two reasons to perform ovariohysterectomies and castrations in dogs and cats," she said. "Obviously the most commonly known reason is to prevent unwanted births. Even more importantly in my mind are the health benefits the pets get as a result of the neutering."
Female dogs and cats that are spayed benefit from the prevention of life-threatening uterine infections, called pyometras, endometriosis, and uterine and ovarian cancer, as well as a reduced risk of mammary cancer. Neutered male dogs and cats can benefit from prevention of testicular infections, known as orchitis, testicular cancer, prevention or dramatic reduction of anal cancer, reduction in incidence of prostatic infections, and reduction in incidence of prostatic cancer.
"It would not benefit the pet at all," Dr. Beck-Ross said, "it would just reduce the pet population by decreasing offspring and increasing disease in the adult pet population and shortening their life-span."
Dystocia in the Bitch (Dystocia means trouble giving birth)
TEXTBOOK OF VETERINARY INTERNAL MEDICINE
Client Information Series; written by Dr Autumn P Davidson
Dystocia can be defined as inability to expel neonates through the birth canal from the uterus. Dystocia is not uncommon in the bitch and can have several causes. The diagnosis of dystocia should be made and treatment insti-tuted in an expedient fashion. An incorrect diagnosis of dystocia may result in an unnecessary caesarian section, but failure to recognize or prioritize dystocia usually results in loss of puppies and perhaps even the dam.
Dystocia can occur as a consequence of problems with the dam's uterus or birth canal or with the fetus. The diagno-sis of dystocia should be based on the presence of any of the following criteria:
1. Failure of the dam to initiate labor at term. Bitches can be considered over term at more than 70 to 72 days from the first breeding, more than 58 to 60 days of diestrus, or more than 66 days from the luteinizing hormone (LH) surge or initial rise in progesterone during estrus.
2. Failure of the dam to enter stage] labor beyond 24 to
36 hours after a detectable drop in rectal temperature to less than 99 to 1000F or to proceed from stage ] to stage 2 labor within 24 hours.
3. Failure of the dam to complete delivery of all fetuses in a timely fashion. Delivery should occur within 30 minutes to 1 hour of active labor (visible abdominal efforts) or 4 to 6 hours of intermittent labor.
4. Fetal distress (unborn puppies with slow heart rates, stillborns).
5. Maternal distress (excessive pain or systemic illness), green or copious vaginal bleeding.
6. Irreversible history of dystocia (pelvic canal abnormali-ties, mismatch between fetal and maternal size) or radio-graphic evidence of fetal malposition.
Your veterinarian's diagnosis of dystocia is based on tak-ing an accurate history, including reproductive history, ovula-tion timing, and breeding dates, and performing a careful physical examination including a digital pelvic examination for the presence of vaginal abnormalities and the presence of a fetus in the birth canal. A handheld Doppler device, abdominal ultrasonography, and x-rays can be helpful in assessing fetal viability, litter size, and fetal position. A blood test to measure calcium and glucose levels may be helpful in identifying metabolic disorders contributing to dystocia.
Uterine abnormalities contributing to the development of dystocia include uterine inertia, abnormalities associated with fetal fluids, and herniation or torsion of a uterine horn. Uterine inertia, failure of the uterine muscle to contract in an effective manner, can be primary or secondary. Primary uterine inertia is multifactorial, with genetic, mechanical, hormonal, and physical components. Bitches exhibiting primary inertia fail to proceed into an effective labor pattern, and cesarian section is indicated. Bitches exhibiting second-ary inertia fail to complete expulsion of all fetuses because of exhaustion of the uterine muscle. Medical management can be attempted, with adequate fetal monitoring, but cesar-ian section may be necessary. Intravenous glucose containing solutions and oxytocin ("pit") and calcium injections can be administered in appropriate doses.
Generally, minute doses of oxytocin are adequate (0.25 to 4.0 units per dog). Spastic, uncoordinated contractions of the uterus occur if oxytocin is administered too rapidly or at too high a dose. Uterine contractions interfere with fetal oxygen supply by compressing placentas. Oxytocin should be administered only with veterinary guidance. Abnormalities of fetal or placental fluids include hydrops, an excessive accumulation of allantoic fluid associated with each fetus, causing the fetal unit to be markedly oversized. Rarely, underproduction of fetal fluids occurs, resulting in dystocia caused by lack of lubricating fluids.
Disorders of the birth canal contributing to dystocia include pelvic abnormalities such as narrowing resulting from a healed fracture or congenital disorders and vaginovulvar abnormalities such as strictures. Successful natural breedings can occur despite the presence of septate (vertical) bands in the vaginal vault. Unfortunately, subsequent vaginal delivery of fetuses is usually impaired. Strictures should be detected by the veterinarian at the time of the soundness examination, before breeding. Anular (circular) strictures are often de-tected at the time of breeding, as they often interfere with the ability to attain a natural tie. These should be repaired before breeding. Bitches with unusually small vulvar open-ings may require a partial episiotomy to deliver puppies vaginally.
Fetal causes of dystocia include fetal oversize; fetal anom-alies; and abnormal fetal position, presentation, or posture. Fetal oversize can occur with prolonged gestation in abnor-mally small litters (especially if there is a single pup) and is the most common fetal cause of dystocia. Fetal anomalies such as anasarca and hydrocephalus (abnormalities of body fluid distribution) can cause a mismatch between the size of the birth canal and that of the fetus. Because both anterior (head-first) and posterior (breech) presentations are normal in the bitch, only a transverse (sideways) presentation is associated with dystocia and is rare. Puppies are normally positioned with the fetal backbone adjacent to the top surface of the uterus. Malpositioning can cause mild dystocia. Abnormalities of posture, normal being fully extended, are the second most frequent fetal cause of dystocia. Malpositioning of the head, forelimbs, or hindlimbs of the canine fetus is not readily corrected with the use of forceps, traction, or digital manipulation because of the limitations of the size of the birth canal of the bitch.
Dystocia: "What To Expect When You Go To The Vet"
Your dog or cat seems to be having trouble giving birth, or seems to have been in labor for a long time, or the expected due date has past, or your dog in late pregnancy seems to be sick: What Do You Do?
Duh...Go to your vet.
What to expect:
If you allow your pet to get pregnant, you need to understand that sometimes things go wrong. Abortions, miscarriages, birth defects, babies born dead, and a greatly increased chance of parasitism, medication sensitivity, disease and death are quite possible.
In an ideal world, the pregnancy is a planned event, the female is young and healthy, under the care of a veterinarian, well vaccinated, not too overweight, and not suffering from parasitism. But even then, pregnancy, especially during birth, is fraught with dangers.
So here’s what to expect when you go to the vet if the delivery event isn’t going smoothly:
History and Exam: Your vet will be interested in the breeding date if known as well as recent appetite, energy level, and any symptoms of illness such as vomiting, diarrhea, lethargy and so forth. The trouble with taking histories of late stage pregnancies is that it’s often normal to feel lousy in late pregnancy.
In addition to all the routine things your vet will be evaluating during the exam, he or she will be paying special attention to:
1. Signs of toxicity which might indicate a dead fetus or uterine infection.
2. A good pelvic exam for discharges, cervical relaxation, and of course a possible baby stuck in the canal. Whether or not we can insert a finger into the vaginal tract to see if the cervix is dilated or not depends, of course, on the size and temperamentt of the animal.
3. Whether or not milk is present ... not all that critical, but it’s nice to know and the presence of milk indicates that gestation is nearing it’s end
4. Body temperature ... it normally drops a couple of degrees within 24 hours of delivery (I don’t know why) ...another indication that the body is ready to deliver.
5. Most important of all; General health and vigor. Is the patient strong enough to go through labor and/or a C-section without aggressive supportive care.
6. We will want to know whether the health of the mom or the babies are more important to you... sometimes we need to make a choice.
What’s next?
After the exam and discussion, you and your vet may decide at this time to either give the situation a little more time, treat whatever other problems may be apparent, or if needed, do a C section.
Or ... more investigation may be in order. If the vet’s sensitive antennai are alerted, blood work or radiographs may be in order. And if you’ve decided a C section is the best course, then blood work to evaluate glucose levels, clotting, liver, and kidney function may be considered advisable or routine.
And here’s something you need to understand: C sections are frequently routine; the patient’s only major problem is getting those babies OUT. But other times patient’s in late pregnancy are extremely sick, toxic, and dehydrated. There may be a dead fetus or severe uterine infection, a bacterial of the blood and/or kidney and both immune and vascular problems. These patients are often calcium deficient as well. Trust your vet and understand that some of these cases require fairly aggressive treatment, are sometimes expensive, and sometimes unsuccessful.
Speaking of expense, this is an aside, but it seems to me that most C sections seem to be needed in the middle of the night. You might want to consider getting pet health insurance if you’re planning on breeding.
If we determine that the cervix is dilated enough and the patient is healthy enough, your vet may give an injection to induce labor. A calcium injection may also be given to strengthen contractions. If this injection doesn’t work within about 30 minutes, it may need to be repeated. If a second injection still doesn’t induce successful labor, well then a C section will probably be recommended. Just like in human delivery rooms, decisions on what to do depends on the situation and the situation can change quickly. In hind sight, we sometimes find we’ve made a wrong or unnecessary decision, but you simply have to trust your vet’s experience.
Maybe your skillful vet will be able to avoid a C section and be able to extract a puppy or kitten stuck in the birth canal. (I tell my students that the 3 most important things in pulling calves, lambs, pups, kittens, or any other species is “Lubrication, Lubrication, Lubrication!”
Sometimes there’s no viable choice except a C section. If so, one of the challenges is that the anesthesia will affect the babies too, so we need to get them out fast, and they may need cpr and cardiac and respiratory stimulation. They may need supplemental nursing until the mother recovers from the surgery.
Misc Comments:
Just because a C section is needed for one delivery in a patient doesn’t mean a future pregnancy will require a C section. Maybe yes, maybe no.
Your vet can spay your cat or dog during the C section if you want.
Agalactia (Lack of Milk)
Dee Cross, Ph.D of Clemson University has developed a product called equitox used to prevent horses from aborting if grazing on fescue. It turns out that this product may be helpful in dogs that don't have milk to support their pups. Have your vet contact him for more information at dcross@clemson.edu or visit his website at www.equitox.com
