Do Other Mammals Experience Morning Sickness?

While we are familiar with the concept of morning sickness in pregnant humans, the question of whether it affects other mammals remains a mystery. This is partly due to the lack of comprehensive research on the topic.

Observations in Pregnant Bitches

It is not uncommon for a pregnant bitch to experience morning sickness, similar to what is observed in humans. The severity and duration of morning sickness can vary significantly among individual dogs. Typically, a pregnant bitch may skip breakfast around three to four weeks into her pregnancy, and this may persist for a couple of weeks. However, the manifestation of morning sickness is not universal, with some bitches not showing signs at all and others experiencing poor appetite throughout their entire pregnancy.

Theories on the Origin of Morning Sickness

Scientists propose several theories to explain the occurrence of morning sickness in humans. One theory suggests that morning sickness serves as a defense mechanism against blood-borne toxins. By rejecting potential harmful substances through vomiting, the body protects the fetus. Another theory posits that morning sickness is a by-product of the conflict between the pregnant woman and the embryo over resource allocation.

The Role of hCG

The hormone human chorionic gonadotropin (hCG) is often linked to the onset and persistence of morning sickness. Women who suffer from nausea throughout their pregnancy tend to experience relief after childbirth, and if the fetus dies, morning sickness often diminishes as HCG levels drop.

Exploring Morning Sickness in Other Mammals

While it is reasonable to assume that other mammals might experience similar symptoms, there is a lack of concrete evidence. The reasons for this are varied. For instance, research on this topic has been scarce, with most studies focusing on humans, chimpanzees, and cats. It is believed that species with more diverse diets, like humans, might be more prone to experience morning sickness as a defense mechanism against harmful toxins.

Alternative Hypotheses

A recent theory proposes that morning sickness and motion sickness may be related through the malfunction of the vestibular sense organs in the inner ear. This hypothesis suggests that dehydration altering inner ear pressure or mechanical alterations in vestibular function could contribute to nausea. For example, alcohol can alter the specific gravity of inner ear fluids, leading to sensations of nausea, much like motion sickness.

Personal Insights

From personal experience, morning sickness in humans and motion sickness in various contexts share similar symptoms. This observation supports the idea that the gravity-sensing organs in the ear might play a significant role in both conditions. Additionally, the physiology of four-legged animals and swimming mammals like whales, with their horizontal brain and ear positions relative to the heart, might make them less susceptible to morning sickness, if it occurs at all.

Conclusion

In summary, while we have some theories and observations about morning sickness in other mammals, the question of its occurrence remains open. Further research is necessary to fully understand the underlying mechanisms and to explore whether and how other mammals, including dogs, experience this condition.