When a newborn Przewalski’s horse foal needed urgent medical help, Highland Wildlife Park keepers called on the park’s vet team to perform a life-saving procedure.
Being the on-call veterinarian for Highland Wildlife Park means being prepared for the unexpected. When keepers called me early one Saturday morning to report a Przewalski’s foal in trouble, I knew that something must be seriously wrong. They are an incredibly tough species that has evolved in some of Earth’s harshest climates. If you spend five minutes watching our herd, it’s clear to see the strong bonds of family and friendship that help them survive and thrive. We are not supposed to have favourite animals but secretly, I think Przewalski’s horses are the best!
Six-year-old mare Oyun is an experienced mum and after confirming her pregnancy earlier this year we were excited to meet her new foal. But that morning, keepers discovered her in distress. She had given birth overnight in a swampy area of the main reserve and her foal was stuck in the mud, exhausted and hypothermic. Keepers Mo, Andy and Phoebe rescued the foal and warmed her up in the vet room. I checked over the 28-kg filly and took a blood sample. My heart sank when I read the results and realised that she had a life-threatening condition called failure of passive transfer. It was clear we needed to act fast to save her life.
All domestic and wild equids rely on disease-fighting antibodies present in the mum’s first milk (colostrum) to mount an effective immune response against environmental pathogens. The passive transfer of immunity that occurs by suckling colostrum in the first few hours of life is vital for the foal to develop a healthy immune system. Because Oyun’s foal had missed this opportunity to suckle, passive transfer had failed and she was now extremely vulnerable to infection and sepsis.
The foal needed a special type of blood transfusion with antibody-rich plasma from a healthy horse. With a weak and vulnerable foal needing urgent medical help there was no time to sedate an adult Przewalski’s horse to collect plasma. Fortunately, with help from a local equine hospital and support from our amazing keeper team and friends of the park, we quickly sourced a bag of frozen plasma from a domestic horse.
I wasn’t sure if a transfusion between a domestic horse and a Przewalski’s horse had ever been done before, so I was anxious as I sedated the foal, warmed the plasma to blood temperature and slowly started the transfusion. Monitoring her heartbeat carefully, we watched for warning signs of an adverse reaction but the foal slept peacefully throughout the transfusion. She came through the procedure like a true champion and was soon back on her feet ready to be reintroduced to the herd. Oyun accepted her foal straightaway and they have been inseparable ever since.
After a tense few days and sleepless nights watching to make sure there were no complications, keepers named the foal Aztai, meaning lucky in Mongolian. Every foal born in captivity represents another step away from extinction for this endangered species and I feel lucky that our team was able to help Aztai. Visitors can see her and mum Oyun with the herd in the drive-through reserve. She is the palest in colour of our three young foals and the clipped patch of hair on her neck from the transfusion is starting to grow back in!