fur
.......Around 5 million fur industry victims are caught in steel traps every year, where they may freeze to death, be killed by another animal, or even chew off their own limbs to escape. A steel trap can't discriminate between animals with valuable fur and 'useless' animals, endangered species, or even domestic pets. These are flung to one side and the traps reset.
Excerpt from "Fur Trapping: A Complete Guide," B. Musgrove & G. Blair:
......."Hit the trapped animal just forward of the eyes with the stick. While it is unconscious, use your knee or the heel of your shoe to come down hard behind the front leg. This ruptures the heart, and the coyote never regains consciousness."
.......Animals on fur farms are kept in cramped, dirty, unnatural conditions that cause insanity, which is manifested in self-mutilation and cannibalism. They are killed by gassing, neck-breaking, lethal injection, suffocation, or electrocution through the mouth and anus (so as not to mar the fur with blood stains or burn marks).
.......One fur coat requires at least: 55 Wild Minks, 35 Ranch Minks, 40 Sables, 11 Lynx, 18 Red Foxes, 11 Silver Foxes, 100 Chinchillas, 30 Rex Rabbits, 9 Beavers, 30 Muskrats, 15 Bobcats, 25 Skunks, 14 Otters, 125 Ermines, 30 Possums, 100 Squirrels, or 27Raccoon.

cat and dog fur
.......It is estimated that 2 million dogs and cats are killed each year for fur. The breeding of the animals for this trade occurs mostly in China and Southeast Asia. The fur (and skin) ends up in clothing and products such as stuffed animals. These are then sold in Europe and the US, among other markets. Cat and dog fur farms are often family-run, with just a few animals per farm. Others raise up to 70 cats or 300 dogs. The animals are kept outside so that their fur will grow thicker. At the beginning of winter the animals are slaughtered and skinned and the fur sold. In keeping with fur industry practice, cats and dogs are kept in dark, dirty conditions. Their diet is designed to give optimal fur growth and thickness, but otherwise the animals' health is not a consideration. Dogs are killed by butchers who string a metal wire around the neck and plunge a knife into the animal's groin region. The dog is then skinned: if it's lucky it's dead at this stage. Cats are killed by hanging, sometimes having water poured into their open mouths to drown them. The meat from the cats and dogs is sold to restaurants or food companies. The fur and skin of the animals is sold to European dealers, who incorporate it into leather and fur products. Manufacturers are not required to name the origin of the fur on products labels, so any leather or fur products that you buy may well include the skin or hair of cats and dogs.

leather
.......Why do so many people point the finger at fur, while seeing no wrong in wearing leather? If you look at people walking down the street, the vast majority will be wearing leather shoes. Leather is seen as a by-product of the meat industry; it’s not. Leather hugely subsidises the meat industry, which in any case is by its nature appallingly inhumane, and the popularity of leather definitely acts as an incentive to produce more of it.
.......A lot of the leather sold in the western world comes from the sacred cows of India, which are smuggled across the borders to countries where laws do not prohibit their slaughter. They are made to walk to their deaths, and animals that fall down are beaten with sticks and have chilli peppers rubbed in their eyes to make them get up. If you've ever gotten chilli peppers on a cut or raw skin you'll know this is extremely fucking sore. Try to imagine how it would feel ground into your eyeballs. As with fur, leather companies are not required to list the origin of the leather on their products. The consumer has no way of knowing exactly what animal's skin has been included in what they buy - be it cows, sheep, etc., or dogs and cats. The animals that give the best leather are the young and the females. Baby animals are undamaged by scratches, parasites, ringworm, dung contamination etc. The grain is smoother and finer, as with that of female animals, which is also softer and more pliable. The softest, silkiest kid gloves come from the boiling alive of kid goats. Calf and lamb foetuses are purposely aborted for the quality of their hides. Flaying snakes and lizards alive is believed to give more supple leather. The expensive skin of ostriches has the feathers removed from it while it's still on the living bird – they’re roughly shaved off or yanked out of the flesh with pliers.
.......Alligator and crocodile farms keep animals on concrete slabs in putrid, stagnant water. Crocodiles are caught with huge hooks and wires and landed when they've lost so much blood that they don't have the strength to resist any more. Alligator farm workers have been filmed smashing animals' heads with metal baseball bats and severing their spinal cords with chisels and hammers. It took up to two hours for some of the alligators to die.
.......Leather as it is sold is not a natural product. In its natural state it would rot very quickly, be hard and brittle in cold weather, and limp in hot weather. It may be seen as biodegradable and eco-friendly, but in actuality tanning modifies the collagen or protein fibres so they stop biodegrading. There are synthetic alternatives to every kind of leather product available, even Doc Marten boots, so there's no reason to support the mistreatment of animals.
.......Tanneries use lime, sodium sulphate solution, emulsifiers, non-solvent degreasing agents, salt, formaldehyde (a recognised carcinogen), formic acid, sulphuric acid, chromium sulphate salts, lead, zinc, formaldehyde, fats, alcohol, sodium bicarbonate, dyes, resin binders, waxes, mineral salts (chromium, aluminium, iron, and zirconium), coal tar derivatives and cyanide-based finishes, which, along with proteins, hair and salt, are released into our ecosystem. Populations near tanneries experience leukaemia levels that are way above average, and tannery workers have very high levels of testicular cancer due to exposure to toxic chemicals used in the tanning process. If this is how ‘natural’ products are made, no wonder we’re destroying the planet so fast.