When people are overwhelmed by their emotions, tears often begin to fall.
Researchers have now discovered that dogs can cry too. For them, however, the tears are mainly associated with positive emotions, such as seeing their loved ones again.
Find out here when and why dogs can cry!
Can dogs cry too?
As much as dogs are part of our everyday life, unfortunately we can’t talk to them. At least not in such a way that we actually get an answer in the form of words and sentences.
We are therefore particularly interested in how dogs think and feel.
The emotions and the bond between humans and animals also occupied researchers from Azabu University in Japan. Takefumi Kikusui, a professor at the university, and his team of scientists sought an answer to the question of whether dogs can cry like humans.
The idea came to them after Kikusui made a discovery in one of his own two dogs.
His poodle lady had recently become a mother. While breastfeeding her newborn puppies, the professor noticed that tears suddenly came to her eyes.
Not only did this show him that dogs seem to be able to cry, it also showed him what might be causing it.
After a few more experiments with other dogs, it seemed clear: dogs can cry when they are happy.
Your tears are probably triggered by a certain hormone.
The cuddle hormone
The hormone “oxytocin” is also known as the cuddle hormone because it strengthens the bond between two people or animals.
It is produced independently in the brain and is particularly important when babies are born. It plays a role in inducing labor, boosting maternal milk production, and subsequently increasing the feeling of bonding between mother and child.
It is poured out more when cuddling.
It is therefore important that newborns can snuggle up to their mother as soon as possible after birth.
The hormone also plays a role for couples. When we hug someone, oxytocin is released and strengthens our bond with that person. It also helps in trusting each other.
The researcher Kikusui and his team had already conducted research on the bond between dogs and humans in 2015. In these, they find that both humans and animals release the cuddle hormone when they interact closely with each other.
It was particularly interesting for the dogs that the oxytocin in their blood increased when they were close to their master or mistress.
To find out whether dogs can actually cry, the scientists performed the so-called Schirmer test on the dogs.
This test is also used on humans and does not harm the four-legged friends. Tear production can be measured with the help of a filter paper in the lower conjunctival sac.
First they brought the dogs together with their owners to get a standard value. Then the pairs were separated for at least five hours.
When they were then reunited, it could be observed that the dogs produced significantly more tears this time.
The experiment thus confirms Kikusui’s assumption. In dogs, the hormone oxytocin is most likely responsible for increasing tear production and causing them to get wet eyes or even a few tears.
It is not yet clear whether dogs also cry when they experience negative emotions, such as sadness, fear, or despair. However, it seems like only positive emotions trigger this in them.
That doesn’t mean that your dog is always overjoyed when there are tears in his eyes. In dogs, wet eyes can also be a sign of illness.
Conjunctivitis, allergic reactions or eye infections can cause tears.
However, if your dog is healthy and you have just met again after a long time, you can look forward to the tears, because your fur nose is very happy about you!