Living with animals

We share our lives with our domestic animals and our relationships with them are many and varied. A cattleman in outback Australia depends on his working dogs to muster a herd, whereas an isolated city dweller relies on their pet to convey a sense of home and belonging. Homing pigeons may have been replaced by regular mail services, but budgerigars have kept their place in many homes, along with backyard laying hens.

In some cultures animals share the same roof as their owners and their survival is completely interdependent with humans. In other situations they play a role in entertainment, on race courses and in sporting arenas. Sometimes animals are a way of connecting and educating us, in zoos, nature reserves and wildlife parks. Many non-domesticated animals have had to endure us destroying their food sources and habitats, even to the point of extinction, whereas domesticated animals are food sources, as well as acting as transporters and facilitators. In many cases, our relationships are mutually beneficial, but in others it is exploitative, requiring the establishment of bodies, such as the RSPCA, to protect animals from human cruelty.

Today, when over 70% of Australians live in cities, most of our contact with other animals is restricted to our pets or companion animals. The Royal Society for the Prevention of Cruelty to Animals (RSPCA) estimates that there are ~28 million pets in Australia. We have one of the highest rates of pet ownership in the world, with 69% of households owning a pet. Of these, 48% are dogs and 33% are cats. Fish and birds constitute a further 15% and 2% are small mammals and reptiles. Australian households are estimated to spend over A$33 billion on pet services each year, with food 51% of all expenditure, and veterinary services 14%.

Horses are less commonly kept as pets, but are incredibly valuable animals. The Australian thoroughbred industry contributes more than $1 billion to the national economy. Our horse industry is second only to that of the USA in terms of the number of mares and stallions held by breeding studs. Rising gambling expenditure, growing horse racing activity and prize money boosts this industry annually. Horse racing is also an iconic part of Australian life, with many people more familiar with the names of successful horses, such as Phar Lap and Black Caviar, than their local parliamentarian or award-winning scientist.

Like humans, animals suffer from infectious diseases. Sometimes these diseases are transmitted to humans. Examples included in this issue are Hendra virus from horses, Brucella suis from pig-hunting dogs, Salmonella and Campylobacter species from reptiles, and the rabies virus from dogs. At other times, infectious diseases can be transferred because of poor animal-husbandry practices or careless food handling. It can also result from the direct or indirect interactions between wild and domestic animal populations, as occurs with Q fever in companion animals. In some instances, infectious diseases in our domestic animals can serve as an early warning of a growing risk to human populations, as exemplified by the incursion of Japanese B encephalitis virus into Australia in recent years. Other papers included here recognise the growing awareness that healthy animals are critical to healthy human populations and environments, the interrelationship that is the basis of One Health, an integrated and unifying approach to sustainably balancing and optimising the health of people, animals and ecosystems.

We need animals and they need us. A poignant example of this is reflected by the statue of a dog called Balto in Central Park in New York, USA. Balto was a Siberian husky that became famous after a heroic journey across Alaska in January 1925. An outbreak of diphtheria threatened the population of the town of Nome, but weather conditions prevented the use of a plane to transport antiserum from Anchorage. A relay of 20 dog-sled teams carried the lifesaving medicine to Nome in 5 days, almost 700 miles [~1127 km], in blizzard conditions. Balto led the last team.

It seems necessary from time to time to remind humans that we share our planet with many other animals and that our wellbeing is mutually dependent. Managing infectious disease in animals, tamed and untamed, benefits humans, both directly and indirectly, and should be recognised and rewarded.

It is our hope that showcasing the work of some of our veterinary colleagues will both inform readers and acknowledge their contribution to our discipline.