Some species do this only under certain circumstances while in other animals the consumption of faeces, known as coprophagy, is classified pathological or abnormal.
Coprophagy can be carried out in various manners. An animal may ingest its own faeces (autocoprophagy), may eat the faeces of other individuals of the same species (allocoprophaghy), or may select the faeces of different animal species (heterocoprophagy).
This activity is common in nature and fulfils important physiological functions of survival. Insects ingest and re-digest the scats of large animals, especially herbivores, where the level of digestion in these plant-eaters is incompetent – dung beetles, flies and certain butterflies are well known for this.
In the hind gut of termites are protozoa parasites which assist these insects in digesting plant material in their diet. In order to have the benefit of these parasites the termites have to eat one another’s droppings.
Rabbits and hamsters produce two types of faeces. During the day they excrete normal droppings which they do not eat. At night their softer faeces, known as caecotropes, produced in the caecum, has to be ingested in order to survive. From cobalts salts in their diet, the bacteria in the intestines of rabbits and hamsters produce vitamin B12, cyanocobalamin.
This vitamin can only be absorbed from the stomach so it has to be reintroduced into the animal by it eating its soft night faeces directly from the anus, as it is excreted. In this way their food passes through their gastrointestinal tract twice.
When hippopotamus and elephant calves are born their alimentary tracts are sterile so they instinctively go about eating the scats of the cows or other animals in the herd to obtain bacteria and flora needed to efficiently digest and obtain the essential nutrients from the vegetation they eat in their environment.
Gorillas and chimpanzees eat their own or the faeces of other members in their group to facilitate absorption of essential minerals, fibre and vitamins.
Carnivores, wild or domestic, will lick up and ingest the faecal plugs of their neonates not only to stimulate further defaecation reflexes during the early suckling stages but also to maintain hygiene and eliminate any traces of their vulnerable offspring to protect them from other predators, as part of their maternal instincts.
Controversially, in some countries, cattle are fed pre-heated chicken droppings to economically and physiologically increase the protein content of the feed. In some low income areas of certain cultures horse faeces is fed to pigs. These practices of artificial coprophagy causes scientific arguments in that it may increase the risk of transferring parasites, but then so does it happen by natural routes.
As far as pets are concerned, dogs are more likely coprophagy culprits than cats. There are numerous factors which play a role in this canine behaviour including age, nutritional quality, breed, hygiene of living conditions, amount of physical and mental stimulation on offer, confinement, boredom, inappropriate punishment from the owners and psychiatric influences. People often complain to veterinarians, animal behaviourists and dog trainers about this behaviour of eating faeces.
Read more on this topic in next week’s Saturday Citizen.