Coco is a regular visitor to our cardiology department as she was born with a heart defect called a patent ductus arteriosus (PDA), which is a heart defect that occurs when the ductus arteriosus (a blood vessel between the aorta and pulmonary artery that allows blood flow to bypass the lungs in the foetus) fails to close after birth.
As Coco was a rescue, her PDA was not found until the pressures in her heart had altered, and the flow of blood through the PDA had reversed, meaning it was no longer able to be repaired surgically.
This has led to a condition called polycythemia, which is caused by an overproduction of red blood cells due to reduced oxygenation related to her heart condition, causing her blood to become too thick. This means that she becomes very lethargic and is unable to exercise.
Coco’s Previous Treatment
Coco is monitored at home, and if she starts to show symptoms a blood sample is taken and her PCV is checked. PCV (packed cell volume %) is the percentage of red blood cells in circulating blood. A normal PCV for a dog is 37-55%, where Coco's has been between 75-80% when she is symptomatic.
When this happens she has to have large volumes of blood taken, and usually has to be admitted to hospital for heavy sedation order for this to be done. Whilst this is done carefully and she is monitored very closely, having to be sedated regularly is not ideal, it's difficult for Coco's mum for travel to us each time (even though she is hugely dedicated), and as her insurance no longer covers this condition, it is also expensive.
Leech Therapy
Our cardiology nurse Emma had an idea at Coco's last visit, after remembering a case that was seen in our medicine department a few years ago - leech therapy!
Our cardiologist looked into the idea further, and discussed it with Coco's mum and the laboratory that provide medical leeches and a plan was put into place to attempt the leech therapy next time Coco needed treatment.
She started to show symptoms again recently (her PCV reached 80%), so she came in to the hospital for her first leech therapy. Four leeches were used, and very successfully reduced the red blood cells to a safe percentage.
As the leeches release a local anaesthetic in their saliva the procedure is not painful, and no sedation was necessary. Coco lay upside down in a big comfy bed having a cuddle with her mum, and once the leeches detached they were placed into individual jars of spring water, ready to be taken home to be taken care of by Coco's mum.
Because the leeches also release an anticoagulant, even after they finish feeding their work continues. The wounds ooze for 24-48 hours, and all the bloody swabs and dressings were collected to be weighed to monitor the exact amount of blood taken.
Coco’s Recovery
Coco had a big bowl of chicken for dinner in wards, and stayed with us for monitoring overnight to ensure that there were no complications. She had a comfortable, trouble free night and the next morning her bloods were rechecked and showed a great result. She was discharged back to mum that day, and she and her new friends are all doing well at home!