Frontline staff should be trained to identify so-called parental alienation, an expert has said.
PA is when one parent undermines the role of the other by turning a child against them following a separation.
Between 2013 and 2016, the Children and Family Court Advisory and Support Service in Wales dealt with 22,670 cases involving children.
The Welsh Government said it was developing information and advice services.
Psychologist Dr Sue Whitcombe said social workers, psychologists and solicitors should receive training.
"This is a severe form of child emotional abuse when at its most severe and pure form and it needs to recognised along with those other types of child abuse," she said.
There are laws in some countries, including Mexico and Italy, which punish parents who alienate one another.
One man, who did not wish to be identified, told BBC Wales his experience of PA had been "heartbreaking".
"There's not a day goes by where I don't think of my daughter," he said.
"You know, I made memories with my daughter - we went to parks, ponds... We weren't one of these that stay in the house. We did everything together.
"Rather than counting down days to her birthday or anything else, something that she should be looking forward to, instead she's counting down the days she hasn't seen her father."
"It wrecks your life, it totally turns your life upside down."
An online petition calls on the Welsh Government to formally recognise PA as a type of emotional abuse of children and proposes funding for mandatory training for professionals.
A government spokesman said: "We recognise the impact parental separation can have on children and the benefit they derive from having an ongoing positive relationship with both parents, where it is safe and in their best interest.
"To support parents who are separating we are developing information and advice services to help them focus upon how they can best support their children and make arrangements that meet their long term emotional needs."