Paul Tweedie, 53, from Carlisle, was distraught when he discovered that Angus, his Boerboel puppy, seemed to be growing sick. Angus had a large bony lump protruding from his jaw and was losing his appetite. “He has big jowls so I didn’t notice it at first but I put my hand under his chin and realised he had a lump which was really big,” said Paul.

Paul had only just got the puppy, which is not a native breed to the UK, but the family had soon grown close to him. Vets in Dalston weren’t entirely sure what was wrong with Angus at first but they soon cracked the case.

Paul said: “They weren’t sure what to make of it and asked me to bring him back the next day and leave him. I think they suspected it was a big cancer. “I was pretty upset – he was only six months and he’s a family pet.”

Calvarial hyperostotic syndrome is so rare that few papers have been written about it. To make sure that they had made the right diagnosis, the x-rays were sent to specialists at Kentdale Veterinary Orthopaedics in south Cumbria who confirmed that Angus had the disease. It is recognised by a swelling of the skull and typically only occurs in bigger breeds.“As the bone is still growing the swellings seem to disappear,” said Graham.

“He still has a slight lump on his jaw but is now back to normal – big and bouncy and doing very well.” Angus was put on medication that controlled his fever until the swelling went down. Now, at 10 months old he is as lively as any young dog would be without a rare disease. “He’s just been playing with his frisbee up the field,” said Paul.“You look at him and he looks ferocious, but he has a lovely nature. “Hopefully we will be together for 12 or 14 years.”