As plans are unveiled to protect animals against abusers BBC news website looks at recent cases where the new legislation could have made a difference.
By the time 10-year-old pointer Dylan was found his tumour had been allowed to grow until it dragged across the floor.
Measuring 18 inches (46cm) by 12 inches (30cm) it accounted for 50% of his total weight and would have taken between six to 18-months to grow, according to the RSPCA.
When he was found, Dylan's tumour accounted for half of his weight
In all this time, his owner had not taken him to the vet.
The vet who eventually saw Dylan said in 17 years of practice she had never witnessed a tumour like it. Dylan had to be put down.
His owner appeared before Teeside magistrates in March last year and was banned from keeping animals for 10 years, ordered to pay £50 costs, carry out a 12-month rehabilitation order and a 100-hour community punishment order.
RSPCA inspectors had given the owner of five-year-old pony Casper advice several times over three months.
But it was repeatedly ignored and the grey pony was finally removed from a field in Hinckley, Leicestershire, suffering from extremely overgrown hooves which were preventing him from walking properly.
Inspectors visited five times before Casper was rescued
The front two hooves were five inches (12.5cm) too long and were turned up in an "Aladdin's slipper".
The pony was sedated and his hooves trimmed, but the back hooves had corkscrewed in on themselves to such an extent, Casper could still only walk on the outside of his feet.
His owner was banned from owning horses for five years and ordered to pay costs of more than £1,000.
Sentencing, the magistrates said: "You had five visits from the RSPCA and five opportunities to put this right, but you failed to do anything."
RSPCA inspectors managed to get into the owner's flat on the fifth attempt.
Inside, inspector Sue Craig had to wear a protective mask against the stench and dirt.
In total, 29 cats were living in the Newcastle flat.
Such was the stench in the flat, inspectors had to wear masks
The floor was caked in faeces and the rooms filled with rubbish.
Twenty-one of the cats had to be put down, with most of them underweight and many pregnant.
The RSPCA had first tried to get into the flat in March 2004, but they could not see through its filthy windows to assess the condition of the cats.
Inspector Craig said: "I was horrified at the conditions I found inside that property and the situation was made worse by the fact I had concerns for weeks before I could get inside.
"Through no fault of the RSPCA, for the 21 cats which had to be put to sleep, I was too late.
"With the new Animal Welfare Bill, the authorities would legally be able to intervene at an earlier stage if they feared animals were are risk."
The owner admitted 14 charges of causing unnecessary suffering to animals and was banned from keeping pets for life when he appeared before Gosforth Magistrates Court in September 2004. He was fined £50 and ordered to pay £150 costs.
A cage of hungry and thirsty puppies, a distressed kitten, an emaciated bearded dragon and hamsters so starved they had begun eating each other, were found in a Wigan pet shop.
Another 23 animals were found dead, including rats and mice.
RSPCA inspector Cathy Hyde, broke into the shop in May 2004 with police assistance.
The RSPCA found a cage of thirsty and hungry puppies in the shop
She said: "This was an incredibly frustrating case.
"I had visited the premises before the discovery in May, but although I had concerns, I could find nothing which would allow me to take further action.
"I was also concerned that the premises were not suitable for the sale of puppies, but again, apart from communicating those concerns to Wigan Council, the licensing authority, there was nothing I could do to stop him.
"Had the Animal Welfare Bill been in place, the new welfare offence would have legally obliged the owner to care for the animals properly."
The owner was jailed for three months in March this year - this was later reduced to one month on appeal - and banned from keeping animals for life - which again was reduced on appeal to 10 years.