I used to rescue guinea pigs, and I got up to about 20. That was my absolute max. I am now down to 2, a pair of boys somebody didn't want any more.
I knew people in the guinea pig community with around 60 guinea pigs. I went to 1 breeders house, and she had about 100. They were kept clean and fed, but it wasn't really good to keep breeding them.
I found a very heart breaking situation a couple of years ago. A young girl in our road (Well, she was about 20, but damaged and immature), took in over 100 animals to her dad's garden. There were about 80 guinea pigs, dozens of rabbits and a ferret. She seemed very happy, and the rabbits were breeding like well rabbits. She was breeding the guinea pigs too, but claimed that was unintentional.
After some weeks passed, I popped round with some veggies for the animals. She wasn't home, but her dad said I could go into the garden. The sight that met me will haunt me forever. Things had gone badly wrong and had completely got out of control. The water bottles were all dry, the food bowls were empty. The guinea pigs were inches deep in their own filth. The cages were over crowded, and the dead bodies had been trampled down. There was no food or hay in the shed. There were bin bags with more dead bodies inside.
Over the next few days, we brought food and water to the 100 or so surviving animals, and cleaned out the cages.
The RSPCA never did come out, but they wouldn't have prosecuted any way due to mental health. I was worried that they'd just remove the animals and put them all down.
Luckily, we managed to find help from some local small animal rescues, and they had a whole other network of more rescues to help. They removed the animals, and got them to safety.
Sadly, I had to take a pair of mother and baby rabbits to the vets, as they had contracted myxi. We were very fortunate that it didn't spread to the others.
I will be forever grateful to the rescuers, and the RWAF (rabbit welfare charity), who funded for all of the rabbits to be neutered and vaccinated, which would have cost over £700.
I will never forget my shock, and seeing all those desperate little faces at the cage doors. Thank goodness help came. But it is shocking how fast things can spiral out of control.