'I blamed my toddler's cough on childhood bug - but it was warning sign for what killed her'

A heartbroken mum is urging parents never to ignore a lingering cough - as it was the first sign of a killer heart disease that tragically claimed her toddler's life. Three-year-old Penny Dunn was a healthy and active toddler who'd only had 'one cold her entire life' before falling ill out of the blue. Courtney Sherwood, 27, said her daughter developed a cough around Christmas last year, but put the tickle down to winter illness. But as Penny's chesty cough continued to worsen, the mum-of-two took her to the doctors three times where her symptoms were blamed on childhood asthma. Just weeks later, Penny was taking part in her nursery sports day when she was rushed to hospital after suffering two seizures. Tests revealed that Penny's heart was both enlarged and beating at a dangerous rhythm, leading her to be rushed to hospital. When Penny's condition failed to improve with medication, she underwent heart surgery to pinpoint the source of the arrhythmia. But just days later scans revealed her bowel and parts of her brain had died due to lack of blood flow. Courtney and her partner Tom Dunn, 27, were told by doctors that little Penny would have no quality of life. The devastated parents made the heartbreaking decision to turn off Penny's life support before she passed away on July 6. Machine operator Courtney was told Penny's heart issues could've arisen by an illness as minor as a common cold, and the parents 'couldn't have prevented this'. After losing her little girl, Courtney is urging other parents to always trust their gut if they're concerned about their children's health. Courtney, from Stonehouse, Gloucestershire, said: "Penny was the happiest, bubbliest little girl ever. She truly became my best friend. "She was just so happy and so clever. She was never ill, I think she had had one cold before this in her whole life. She was a healthy child. It was around Christmas time last year, she had a bit of a cough but we thought 'it's the winter, it's normal'. "It went away for a bit and then it came back and never went away again. We were told she had a childhood bug, but the cough wasn't going away and it got to the point where she started throwing up from it. "We have to walk upstairs to our doctors and she was so out of breath for at least five minutes and the doctor said 'that's not right for a three-year-old'. They gave her inhalers. It seemed to kind of do something so I thought 'maybe it is asthma'. "When she lay on her side she was better. Now we know it's because her heart was crushing her lungs so lying on the side took the pressure off. The next couple of weeks she went from really happy and running around to being lethargic and refusing food. I could see she was losing weight." Penny was taking part in her nursery sports day on June 29 when her mum received a dreaded call that she'd suffered a seizure. The tot was rushed to A&E where doctors found Penny's heart was beating abnormally and not pumping blood around her body effectively. After medication proved unsuccessful, Penny was transferred to hospital where she was placed on an advanced life-support machine to aid her recovery. Penny was later diagnosed with dilated cardiomyopathy (DCM) - a disease of the heart muscle where heart chambers become enlarged and the heart's muscle wall becomes thinner and weaker - and she underwent surgery to fix the source of the arrhythmia. Courtney said "We were all so excited because she came out of theatre and her heart rate was so stable. I thought 'our little girl is going to come home', we thought we were finally getting somewhere. "She seemed completely fine, but we went in the next day and her abdomen was really hard. We got to hospital on the Monday morning, I looked at her brain activity chart and I could see something was different. My heart dropped because I knew you can fix the heart but you can't fix the brain." CT scans showed that parts of Penny's brain and bowel had died due to lack of blood flow, leading Courtney and Tom to make the heartbreaking decision to turn off her life support. Courtney said: "I do not blame anyone because they tried their best, they were phenomenal. She was at a point where she would not have any quality of life if she survived, she'd have to stay incubated on a machine forever. "We don't know why this happened. The doctor said there's pages and pages of things that could've caused this. Doctors told us we couldn't have prevented this, they said it could've come from simply a cold. "I don't want to scare parents, but she had a cold in December and it went downhill from there. I think there should be a children's ECG machine in every GP. For parents - definitely trust your gut. If you're not happy, get a second opinion."