Second trimester (Day 22 - 42)
The most formative stages of fetal development
The time has come when we find out if my girl is pregnant. This stage includes some of the most formative stages of fetal development. However, during this time, the pups are vulnerable to damage and birth defects and I will be paying close attention to her environment, and stress.
What’s Happening? I find this trimester very interesting and is such an important development stage to healthy puppies. As we close in on the end of the first trimester, and early into the second trimester, the embryonic puppies become elongated as their nervous system and organs begin to develop. They're now about 10 mm or 1/3” long, and 7 mm wide, regardless of breed.
Between Days 16 and 21 post ovulation, the embryos finally stop floating freely and implant in the lining of the uterus. The embryos space themselves throughout the two horns of the uterus before the puppy and the uterine lining connect through the placenta. The placenta is a temporary organ that supports the growing puppy with oxygen, nutrients, antibodies, and other substances, and removes waste products like urea and carbon dioxide. Dogs have what is known as a zonary placenta. An unusual aspect of dog placentas is that during its development, some of the bitch's blood vessels are destroyed, releasing large amounts of blood at the edge of the placenta. This blood breaks down during the remainder of pregnancy, providing the puppy with iron, and leaving a green-colored mass. During the early part of the second trimester, when the placenta and pup's organs are developing, both dam and pup are sensitive to a variety of things especially nutritional and toxins (smells). The demands on the bitch's body are quite significant as she creates placentas and puppies and the care I provide is critical to a successful pregnancy.
Ultrasound Image
By day 28 after ovulation, the embryonic pup becomes somewhat recognizable as a puppy, and is clearly visible on an ultrasound. It is the size of a walnut.
Towards the end of the second trimester, I’m likely to observe changes in my girl physically and behaviorally during this three-week period. Around day 35, some girls will begin to show some mammary gland, minor mammary gland development as prolactin continues to elevate. Her coat may thin on her belly and her nipples may darken. She may begin to sleep more and more soundly. She is likely to run and play a little less. She may groom herself more than normal, insisting on keeping herself very clean. This is perfectly normal as her body prepares for whelping and lactation.
Feeding and Supplements
She will continue the supplements and food that I have been using during the first trimester but will be increasing the amount of food I’m feeding to 150 to 180% of her normal, pre-pregnancy ration until I have the ultrasound results. Once pregnancy has been confirmed and I know how many pups I might be expecting (understand that ultrasounds aren’t perfect), I will adjust her feeding amount based on the assumed litter size
❑ Small litter – leave her at 100% of her maintenance amount (1-4 pups)
❑ Average litter – increase her food to 150% of maintenance over the second trimester (6-9 pups)
❑ Large litter – increase her food to 180% of maintenance over the second trimester (9+ pups)
Exercise
My girls get regular exercise during the second trimester but I make sure that those activities aren’t mentally stressful to her. Exercise is so important in the preparation of her last trimester. She needs to be in as good shape as possible to be able to withstand the long hours of whelping. Some of her exercises include:
❑ Strength training, focusing on core exercises, but also doing some rear and front. Core strength in particular will help her whelp more easily.
❑ One balance exercise a session. These exercises will improve her ability to move around her pups and in/out of the whelping box safely.
❑ Two to three flexibility exercises a session. Flexibility is essential for the bitch to naturally whelp pups and to keep herself clean after the pups arrive.
❑ Lots of good for the soul exercises for stress management and mental stimulation.
By now you know that pregnancy has been confirmed but we still have a long way to go. As you can see, each trimester plays a significant part in the development of the puppies and the health both physically and mentally for the soon to be mom. Raising healthy puppies starts with a healthy pregnancy.
Sincerely,
Tygold Golden Retrievers
Kelly Tynan