The domestic dog is member of the Canis genus, and is the most widely abundant carnivore. It is the first domesticated specie and has been selectively bread over millennia for different sensory capabilities, behaviours and physical attributes. Although their main ancestor is the wolf, dogs nowadays vary widely in shape, size and even colour, having many roles in the life of people. They are used for hunting, herding, pulling loads, protection, assisting police and military, companionship and, more recently, aiding handicapped individuals. Although they are dubbed as “man’s best friend”, their constant breeding has lead to an overpopulation of dogs.
Many are abandoned on the streets, and due to the lack of neutering, their number on the streets increases. Even if shelters are taking care of part of them, negligent owners are still the cause of the overbreeding and spread of the stray dogs. This is a phenomenon that takes place all over the world, with approximately 3.9 million dogs that enter shelters every year in USA. It is impossible to determine how many stray dogs live in the United States, however, the average number of litters a fertile dog produces is one per year, with the average number of puppies being four to six. Many strays are lost pets who were not kept properly indoors or provided with identification. If they do not know how to return home, they can add up to the growing number of feral dogs.
The problems stray dogs can cause, or are subjected to, range from bitten people, dogs walking freely on the streets, loud barks when dogs fight, the threat of walking into a street and facing a pack of hungry stray dogs, traffic accidents caused by dogs, dogs becoming road kill, poisoning feral dogs, endless conflicts in society regarding the actions that need to be taken.
Whether they are stray or feral dogs, they can pose a threat to the human population that comes in contact with them.
Distribution and description of dogs
There is an estimate that the global population of dogs is at 900 million and rising. From this world wide total, a huge amount are feral dogs, which live their lives as scavengers and have never been owned by a human. This leads to an aggressive response from their part when they are approached by a human, or they prefer to just run away.
Street dogs can live virtually anywhere in cities, or rural areas. They can be purebreds, or mixed breed dogs, as once they are on the streets for a long time, if they are not spayed or neutered, dogs will mate with each other no matter their breed. Street dog overpopulation can cause problems for the societies in which they live, so campaigns to spay and neuter them are sometimes implemented. They tend to differ from rural free-ranging dogs in their skill sets, socialisation, and ecological effects, but the threats they pose are real.
Despite their close genetic relationship and the ability to inter-breed, there are a number of diagnostic features to distinguish the grey wolves from domestic dogs, and thus, from stray and feral dogs as well. Their proportions differ, and the behaviour as well, as dogs generally show reduced fear and aggression compared to wolves.
Due to their domestication, dogs have bred for a long time for various behaviours, sensory capabilities or physical attributes. This is why the modern dog breeds are extremely varied in size, appearance and behaviour, especially when compared to any other domesticated animal.
Being a predatory mammal, the dog has strong muscles, teeth made for catching and tearing, and a cardiovascular system perfect for sprinting and endurance. Theirs coats of fur can either be “double” for breeds used to living in colder regions, and “single” for those living in a hotter climate.
Their size can vary in height and weight, from a Yorkshire Terrier at only 113 grams, to an English Mastiff which can weigh 155.6 kg. the tallest breed is the Great Dane, which can reach 106.7 cm at the shoulder. The difference in overall body size between a Mastiff and a Terrier is over 30-fold, yet both are members of the same species.
No matter their size, the senses of a dog are developed in the same way. While they have a visual system developed to aid proficient hunting, they can better distinguish moving objects, than the colour these have. The eyes of different breeds of dogs have different shapes, dimensions, and retina configurations. Most breeds have good vision, but some show a predisposition for myopia, such as Rottweilers.
When it comes to hearing, the frequency range of a dog’s hearing is 16-40 Hz and up to 40-60kHz, which means they can detect sounds far beyond the limit of the human spectre. They also have ear mobility, which aids them in pinpointing the direction of a sound.
The olfactory cortex is the one that dominates a dog’s brain. They have forty times more smell-sensitive receptors and have mobile nostrils that aid them in determining the direction of the scent. This happens due to their wet nose which is essential in determining the direction of air current containing the smell. This is a sense that developed mainly to aid dogs in their hunts, but remained with the domestic ones as well.
The taste buds of dogs are significantly fewer than those of humans, with 1,700 vs 9,000. They do dislike bitter things, which is why many products that are meant to protect furniture from being chewed by dogs have been developed with this thing in mind. They also have a particular increased sense when is comes to tasting water, with special taste buds, that, when active, give the dog an extra pleasure when drinking water.
When it comes to their touch sense, their whiskers are highly important. These can be found above the dog’s eyes, below their jaw, and on their muzzle, and are sophisticated sensing organs. With the help of whiskers, dogs can detect air currents, subtle vibrations, and objects in the dark. They also provide an early warning system for objects that might strike their face or eyes, and probably help direct food and objects towards the mouth.
Depending on the breed, dogs can be prone to certain disease such as: elbow and hip dysplasia, blindness, deafness, pulmonic stenosis, cleft palate, and trick knees. They can also be susceptible to parasites such as fleas, ticks, and mites, as well as hookworms, tapeworms, roundworms, and heartworms. They can also be vulnerable to some of the same health conditions as humans, including diabetes, dental and heart disease, epilepsy, cancer, hypothyroidism, and arthritis.
Also depending on the breed, the lifespan of a dog can vary. These can range from 5.2 years in the Dogue de Bordeaux to 6-7 years in breeds such as Miniature Bull Terriers, Bloodhounds, and Irish Wolfhounds. The longest living breeds are Toy Poodles, Japanese Spitz, Border Terriers, and Tibetan Spaniels, with a have median longevity of 14 to 15 years. The typical lifespan of a dog depends on the conditions they live in, and it is said that in mixed breeds, it can also be longer with 1.2 years than in pure ones.
Breeding and dietary information
Sexual maturity in dogs happens around six to twelve months in both males and females. After this point, females experience estrous cycles semi-annually, and at the peak of the cycle, they are ready and receptive for copulation. They can mate with more than one male, and once the embryo attaches itself to the uterus, the gestation can last between 58 and 68 days. An average of a litter consists of around six puppies, though this can also vary based on the breed of the dog. The larger the breed, the more puppies are born in one litter, with an average that can also reach twelve.
Due to the high number of puppies in one litter, some owners choose to neuter their dogs, in order to eliminate their ability of reproducing. This is good, especially when it comes to countries which are overpopulated with dogs. Many control agencies support this action done by the owners, as it prevents the abandon of unwanted puppies, which would thus add to the millions of stray dogs already existing. Because too many pets exist in USA homes, there is an estimate that 3-4 million cats and dogs are put down each year, while many more remain confined in cages in shelters, as they are not adopted, or just roam freely on the streets, because they are abandoned by their owners. These dogs are especially problematic if not neutered, as they are able to freely breed and expand the number of feral dogs found currently on the streets. Only 10% of the animals received by shelters have been spayed or neutered. Overpopulation, due to owners letting their pets accidentally or intentionally reproduce, sees millions of these “excess” animals killed annually.
Dogs are amongst the most intelligent species, being able to learn over 200 different items. They also have advanced memory skills and are able to read and react to the human body language, especially gestures and pointing, and to understand human voice commands. Their behaviour is also massively shaped by their contact with humans throughout time, thus separating the modern dog from its ancient ancestor.
Dogs are known to also be a highly adaptive species. To survive in modern cities, street dogs must be able to navigate traffic, and some can also learn how to use the pedestrian crosswalk as they got accustomed to the flow of pedestrian and automobile traffic in large cities.
When it comes to their diet, dogs are described as carnivores or omnivores. They do have a wide ranging diet, and are not dependent on meat-specific food, as they can easily digest even vegetables and grains. A stray dog will eat almost anything a human might classify as edible, including candy, fruit, or fast food. The most important factor in their diet is the smell of the item. A sweet-smelling bowl of sugared fruit will be more enticing than a garden-fresh piece of broccoli. When desperate, stray dogs will often eat plastic containers that smell like food. It is common for dogs, whether stray or domesticated, to eat less during warmer months. When the cold weather kicks in, dog appetites generally increase and they will consume more food. Their digestive system can also balance itself and prevent illnesses and other health problems, especially when food is scarce.
Dogs as pests
Because of the lack of care for them, dogs that end up on the streets can either be caught and taken to a shelter, where they do have the chance of someone adopting them. Those that remain on the street, however, pose a serious risk to both humans and household pests. Dogs are carriers of rabies, and due to the fact that they often feel threatened, and can become aggressive, they can cause injuries to humans or even kill household pets, if they get involved in a fight.
Stray dogs can become a nuisance due to the noise they make, the fact that they form packs and are prone to attack if they are scared. Canine camaraderie is not uncommon in stray dogs. In large areas with innumerable strays, packs can form. A pack of stray dogs will have a hierarchy similar to that of wolves, with the alpha dog directing the pack’s movements around the neighbourhood. Stray dogs are less stringent on the roles of male versus female in the alpha position. Any dog of any sex can hold the position until another challenger ousts them.
They can pose increased health risks to the public and pet population. They can transmit diseases such as Parvovirus, a highly contagious, extremely unpleasant viral infection among dogs, and Distemper, which starts with flu-like symptoms eventually affecting the animal’s nervous system. Abandoned pets can also face starvation and this makes them even more aggressive when dealing with other animals and humans encountered on the street.
Stray dogs live on the outskirts of humanity and are usually leery and mistrustful of humans. They will live anywhere they can, as they will want to find a dry and safe place in a relatively quiet area. This instinct for protection makes the underside of decks and porches ideal areas for a stray dog to live in. These canines have been known to crawl into drain pipes and sewers to find adequate living space. More often than not, a stray dog will be nomadic, rarely finding a location that is safe for a long period of time.
Depending on the area where you live, whether it is in a city or in the country side, different preventive measures can be applied, and also control measures, should you already have a serious problem and need to get rid of a pack of dogs. Certain steps can be taken in both these situation, but the most common are exclusion, repellents or the trapping of these pests. The active laws in your country can also affect the ways in which you need to approach this issue.
Details of prevention methods can be found in our “Prevent infestation with stray dogs” article, and a list of eradication methods can be found in our article about “How to get rid of stray dogs”. With millions of such animals roaming the streets world wide, it is important to learn how to protect ourselves against them, but also ways in which we can diminish their growing number, which poses a constant threat to humans and other animals alike.