The intelligence of pigs and the comfort of dogs

Katie died two weeks ago. I still see her shadow in the corner of my eye. I still hear her breathing during the moments between waking and sleep. I look at the spot where she used to sleep and feel a vague emptiness. I miss her. An energetic and intelligent pup, Katie came to live with me some fifteen years ago. Several months later, another German Shepherd pup joined us. He has been very quiet and clingy since his mate’s death. Clearly, he misses her as well.

Dogs are intelligent animals. They have distinct personalities and many humans delight in their company. Unlike other animal species of similar intelligence, in Australia we do not consider them as food. Pigs are not so lucky. Pigs are more intelligent than most dogs and three year old children. Like dogs, pigs are clean animals and can be trained to do similar tasks. According to the RSPCA, pigs make great pets. But we eat pigs and take dogs as much loved companions.

Many people are horrified when confronted with the reality of ‘puppy factories’, but give little thought to the inhumane conditions in piggeries. This is understandable, as we encounter dogs daily, but few people would have had a chance to look inside a piggery or meet a pig on a farm.

There are hundreds of breeds of the domestic pig, but the Australian Pig Breeders Association covers only nine. The majority of the breeds are descended from the Eurasian Wild Boar. Pigs were first domesticated some 9,000 years ago, possibly even earlier in China.

Pigs are omnivores, but prefer and thrive on roots, nuts and grain. Their digestive system and nutrient requirements resemble those of humans. They have been and are being used in biomedical research as general surgical models of most human organs and systems, for cardiovascular research and in transplantation and across-species research.  

The expression ‘to sweat like a pig’ lacks an anatomical basis. Pigs have no functional sweat glands and can’t sweat. To cool down and protect themselves from sunburn, pigs wallow in mud. For them, the cooling effect of mud is superior to that of water. Pigs prefer a clean mud hole to one that has been soiled by urine and faeces.

Wallowing in filth is not a natural characteristic of pigs, but in temperatures above 35 degrees Celsius a pig deprived of clean mud holes will become desperate and begin to wallow in its own faeces and urine in order to avoid heat stroke. Pigs seem to have so much fun in the mud that wallowing could be hardwired and rewarding in itself.

The average life span of a wild pig is 25 years and 12-15 years for a domestic pig, depending on the breed. A sow can give birth to a litter of seven to twelve piglets that weigh about 1.5 kilograms at birth and double their weight in just seven days. At the time of slaughter, usually at the age of six months, a domestic pig in Australia weighs around 74 kilos. Over 4.6 million pigs were slaughtered for meat last yearin Australia. Nearly all of these pigs were raised in factory farms, out of the public eye. In comparison, 3.4 million dogs live in Australian households. Every third household has a dog and dogs are a common sight in our streets.

Like dogs, pigs are social animals and have a highly developed social structure. They form close bonds with each other and other species, including humans. Like us, they communicate through sounds. Low-pitched sounds such as grunts are used to maintain social contact with group mates, while louder and longer high-pitched calls like squeals or screams are an expression of excitement and stress. Nevertheless, during chronic stress and chronic pain most animals seem to stay mute.  

At two to four weeks of age, the piglets in factory farms are taken away from their mothers and crowded into pens with metal bars and concrete floors. The pigs endure overcrowding and confinement for their entire short lives. In contrast, puppies stay a few weeks longer before they are separated from their mother and ‘adopted’ by humans.

Within three days after birth, the piglets’ sharp needle teeth are clipped with a pair of nail clippers. Their tails are cut off − to reduce tail biting from stress − before the piglet is seven days old, using ‘a scalpel, emasculators, surgical clippers or a cauterising cutter.’ Castration occurs between the age of two and seven days with an ‘extremely sharp knife’ or a scalpel. No anesthetic or pain relief is provided. We treat our pets with more compassion. Trained vets using anesthetics and analgesics undertake surgical procedures. One of my previous dogs even stayed overnight in an animal hospital for surgery.

During their unnaturally short lives, factory farmed pigs live in misery. They are confined in cramped quarters with nothing to do all day. No wonder they become stressed and aggressive. Breeding sows are confined in sow stalls or farrowing crates for most of their adult lives. Their muscles and bones deteriorate because they are unable to exercise, and they may have great difficulty in standing up or lying down.