What is Hypoluteoidism?

Hypoluteodism is a rare condition where there is insufficient production of progesterone to maintain pregnancy. It can be a cause of pregnancy loss.

How progesterone is produced

Dogs have thousands of immature eggs, known as oocytes, in their ovaries. Each egg lives in a small sac of fluids (containing steroids and various hormones) which is called a follicle.

During the process of ovulation, the egg breaks through the follicle, and travels through the fallopian tube, to be (possibly) fertilized. The follicle that is left behind, expands and transforms into the corpus luteum. The corpus luteum produces and secretes progesterone, which prepares the body to sustain a pregnancy.

When progesterone is too low in a pregnant bitch

If during pregnancy, progesterone levels are too low, puppies can die in utero or be spontaneously aborted. However, it cannot always be determined why progesterone levels are low. The most common reasons are inadequate production of progesterone by the corpus luteum, or fetal problems.

What are the signs of hypoluteoidism?

The signs of hypoluteoidism can be non-specific and similar to those of pregnancy loss or premature labor, including appetite loss, bloody vaginal discharge, issues with fetal development (low heart rates and inactivity), and premature birth.

Treatment of hypoluteoidism

If your bitch is diagnosed with hypoluteoidism and the puppies are still viable, progesterone supplementation will likely be necessary to give them the best chance of survival. 

Care must be taken to avoid supplementation in the first trimester of pregnancy to prevent side effects to the female fetuses, which include masculinization. Progesterone supplementation should also be stopped a few days before expected birth to support milk production & parturition and parturition.

Progesterone supplementation should always be done with the direct supervision of a veterinarian.

Prognosis for bitches with hypoluteoidism

Some litters can be saved with progesterone supplementation. If puppies have died in utero, the bitch may need surgery to remove fetal and placental tissues. Future pregnancies will likely necessitate frequent ultrasounds and progesterone testing.

References and resources

VIN: Pregnancy Loss and Abortion in Dogs

DVM 360: How to manage the pregnant bitch

Pet Place: Understanding the Canine Reproductive Cycle

World Small Animal Veterinary Association World Congress Proceedings: Understanding and Monitoring Canine Pregnancy

Concannon, P. W. (2011). Reproductive cycles of the domestic bitch. Animal reproduction science, 124(3-4), 200-210.

Greer, M. L. (2014). Canine reproduction and neonatology. CRC Press.

Johnson, C. A. (2008). High-risk pregnancy and hypoluteoidism in the bitch. Theriogenology, 70(9), 1424-1430.