by Mary Ann Sheller, DVM
The canine uterus is a Y-shaped organ…essentially there are two long tubes (uterine horns) running from the ovaries to the cervix. After fertilization, the embryos float around in the horns, eventually coming to rest at various points along them. At about 18-19 days, each becomes attached and begins to develop a placenta. Amazingly, the spacing of the embryos is usually pretty regular along the uterine horns…no one really knows how this happens.
By about 24-28 days, the fetuses can be detected in many cases by palpation of the abdomen. This is because each attached fetus develops a placenta and a sac of fluid which protects the puppy. These sacs can be felt as a chain of balls which can be run through the fingers. Pregnancy can also be detected at this stage by ultrasound or by the use of the relatively new ReproCHEK pregnancy test. By 30 days or so the balls spread toward each other and the uterus becomes tubular again…pregnancy can no longer be detected by palpation until very late in gestation when puppy heads can often be felt. Both the blood test and ultrasound will be accurate through the end of the pregnancy.
As the pregnancy progresses, the uterus gets longer and bigger in diameter, expanding to accommodate the number of puppies there are. In a 70# dog, it can be as long as a yard or more for each horn, and will be about 3-4” across.
- Twelve to twenty-four hours before whelping, sudden progesterone drop causes a drop in temperature. This initial event is the onset of stage one labor.
- Uterus begins to contract and tighten around puppies…sometimes known as “lumping up”…these contractions are mild and involuntary. This stage can last several hours, even a day. Most bitches will not eat during this stage, and will be restless.
- A horn of the uterus contracts progressively more. The first puppy is pushed against the cervix and causes it to dilate.
- At complete dilation, the puppy enters the birth canal…at this stage the uterus, cervix, and birth canal (vagina) is are one long continuous tube with no distinct separation between structures.
- Begins when puppy enters the birth canal.
- Bitch will be panting heavily; visible contractions are seen, sometimes crying.
- Contractions are now voluntary…the presence of the puppy in the birth canal stimulates her to push…and you should see purposeful straining.
- Water bag may appear between lips of the vulva, or bag may break internally and a gush of liquid will be expelled.
- Puppy should appear within 2 hours of onset of stage two labor.
- Between pups, bitch may rest for a few minutes to a couple hours. Never allow straining longer than an hour without contacting your veterinarian (the first pup can take a bit longer).
Call your veterinarian if:
- Labor doesn’t progress.
- More than an hour of straining without a puppy delivered.
- More than four hours between puppies.
- Green or black discharge before the first puppy is delivered (this is normal to see during delivery, not before delivery).
There are two ways to do caesarians…on an emergency basis or as an elective procedure. Hopefully none of you will have need of an emergency c-section, but it is best to be prepared, because there are many things that you and your veterinarian can do to allow the best possible outcome.
Discuss the impending whelping with your veterinarian, especially if there is some reason to believe a caesarian might be needed (older bitch, breed factors, previous history). Make sure that you and your veterinarian are in agreement as to when and whether a section should be done. You should openly discuss and make decisions about puppy survival versus stress on the dam. For example, are you willing to lose a puppy or two to avoid surgery? Are you willing to hand raise 10 puppies if mom’s milk doesn’t come in after the caesarian? These factors will affect how soon your veterinarian proceeds to surgery versus attempting delivery with drugs or allowing more time for the pups to be born.
Find out how often your vet does caesarians. As with anything in life, if you do something often, you get better at it. Some veterinarians only do a section every few years; others do them much more often. Some vets refuse to do certain breeds (bulldogs, most commonly) or don’t do them at all. Some vets will make themselves available at any time to breeders if they know a litter is expected, others will not be reachable after office hours (if the latter is the case, you can research the nearest emergency clinic the same way).
Ask about the anesthetic protocol your vet uses. Although there are many good anesthetics that can be used for caesarian surgery, some should always be avoided. Metofane (methoxyflurane) and Rompun (Xylazine) have both been associated with higher puppy death rates, these should never be used. My personal choice is to induce anesthesia with Propofol and maintain with a combination of Propofol and Isoflurane. Both of these drugs are eliminated quickly, even from puppies, and I find that both puppies and dam are vigorous and strong after surgery. In fact, the drugs wear off so quickly, it’s very important that mom receive pain medications during and after the puppies are delivered to avoid unnecessary discomfort. Other good options are Ketamine/Valium induction followed by Isoflurane; sedation followed by epidural; Isoflurane mask induction (not for bracheocephalics).
Ask whether your veterinarian routinely uses IV fluids for caesarians. This is something you should absolutely insist on (actually, your vet should insist on it). An IV catheter allows us to give drugs quickly if emergencies arrive, and most importantly, keeps the bitch’s blood pressure up and greatly increases the chance that mom’s milk will come in well.
Find out if your veterinarian routinely entubates the mother for surgery. This is another absolute must do. An endotracheal tube protects the mother from inhaling fluids if she vomits (and often bitch’s haven’t been fasted if the caesarian is unexpected). A tube also provides much higher levels of oxygen than room air does, which can be life saving to stressed puppies in the minutes before they are delivered.
Ask your veterinarian if you are allowed to observe/help with the delivery and puppy revival. Some vets are very amenable to this, others are adamantly opposed. Neither approach is right or wrong, but you should know ahead of time if you strongly want to be there for the delivery. Many veterinarians will prefer to start the IV and induce anesthesia before allowing owners in the surgery.
During delivery of the pups, be prepared to help, but do not get in the way. You do not want your vet or the assistants to have to run around you or be delayed in rousing the pups or taking care of mom. Save your questions for after all the pups are out and stable…speed is important to minimize sedation to the pups.
There are a number of reasons for choosing to do a caesarian before the bitch actually goes into labor. Certain breeds are strongly predisposed (Bulldogs, French bulldogs, several of the giant breeds). Bitches that have had previous c-sections are likely to need them for future litters. Single puppies often don’t cause adequate contractions and require sections.
If you know or believe you will need a caesarian, there are several advantages to doing it during the regular office hours of your veterinarian. Costs are often a bit lower, but much more importantly, the veterinarian will have more trained staff members to help with the successful delivery. Your vet will also be better rested and less stressed then he/she will be at 2am.
Before the use of progesterone testing became routine, it was risky to do planned caesarians based on breeding dates (and this still should not be done if no progesterone testing was done). This is because breeding dates can be much earlier than actual ovulation, meaning that puppies delivered 63 days after a breeding could be 7-10 days premature in some cases. Premature puppies rarely survive. Progesterone timing for breeding allows us to very accurately predict whelp date, and therefore to plan caesarians without risking prematurity in the pups. Progesterone testing can also be used at the end of the pregnancy…progesterone levels drop abruptly about 24 hours before labor begins, so daily testing at the end of the pregnancy (if you don’t have earlier tests to go by) can tell you when it is safe to deliver.
Your veterinarian will usually send you home with the bitch and puppies within an hour or two of the surgery. It is important to supervise the mom and litter for at least the first 2-3 days at all times. Some bitches will not be maternal or not realize that she has even had puppies. This is especially true for first time moms. Bitches will sometimes maul or kill the entire litter if left alone with them during this critical time. Fortunately, in most cases, maternal instincts kick in nicely within a couple days.
Monitoring the pups for weight gain is especially important for section pups. Mom’s milk doesn’t always come in immediately (and occasionally never does), and the quickest way to detect this is to notice that the pups aren’t gaining weight appropriately (they should double their weight in the first 10 days).
You should watch the incision site for drainage or redness. In most cases, the incision will be on the belly between the mammary glands, so usually are not bothered by the puppies, but large mammary glands can prevent air getting to the wound and possibly allow infection. You can prevent this by simply checking the wound a couple times a day, and wiping it with hydrogen peroxide if it seems a bit moist. Of course, contact your veterinarian if it doesn’t appear to be healing normally. There may or may not be visible stitches…if there are, they will need to be removed 10-14 days after the surgery.
Mary Ann Sheller, DVM
Vale Park Animal Hospital
2606 Valley Drive
Valparaiso, IN 46383
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