At just 11 ounces and only four inches tall, young Tyson the pup will never be the biggest dog in a fight.
Infact, the tiny pooch - thought to be Britain’s smallest dog - is so minuscule he has to be carried around in a hamster cage.
Young Tyson, who was rejected by his siblings at birth, has a head smaller than a golf ball and is lighter than a bag of sugar.
He is so tiny that owner Rosemarie McLinden, 46, cannot even find a collar small enough to fit him
She has even been forced to build a special crate for Tyson to live in, as his bigger siblings think he is just a toy.
Rosemarie said she believes her pet - who can stand in the palm of her hand - is one of the smallest dogs in Britain.
The mum-of-four added: 'He was tiny when he was born and he was eventually pushed out by his brothers and sisters because he was so tiny. He just hasn't really grown since.
'I had to start feeding him myself as he couldn't latch on to his mother. He was so small he just could not breastfeed due to the tiny size of his mouth.
'I bought a little dropper and had to feed him day and night every two hours until he was a little bigger.
'We had to take him away from the rest of the litter because he is so small they think of him as a squeaky toy.
'I've been doing a lot of research and I can't see a smaller dog anywhere in the entire country.'
Tyson was born on March 30 this year as part of the litter of five and is a Lhasa-Chi - a cross between a Lhasa Apso and a Chihuahua.
But he was immediately unable to eat properly and began to lose pace on the rest of the litter straight away.
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Rosemarie and bus driver husband Antony, 47, rushed the dog to the vets who couldn't find anything wrong with him and were given special feeding instructions.
Although fit and health he is now barely a quarter of the size of his four brothers and sisters - who tower over him at seven inches tall and weighing three times as much as him.
Rosemarie added:'They are all so boisterous, but he is just too small to be boisterous, he's just an energetic loving pup.
'He loves toes, he will chase them and give you a nip, but they are bigger than him.
'He has one ball that he likes to chase, we found a practice golf ball that he can use, but even that is bigger than his head.
'We've just started trying to wean him onto dog food, and we have to rub around his little gums to help him eat.
'He seems do be doing well though and we hope he stays fit and healthy.'
Tyson joins a menagerie of animals at the family home in Keal Cotes, Lincs., as the smallholding already had two kittens, a bearded dragon, sheep, horses, chickens and even a hedgehog.
Vet Sharon Crocket, of Pilgrim Veterinary Surgery, in Boston, Lincs., where Tyson has been treated, said: 'He could possibly be the smallest dog in the UK.
'He is so tiny, even for a part Chihuahua.'
* The previous smallest dog in the UK was five-inch tall Yorkshire terrier Pagan, from Hull, Yorks.