Dogs and viruses

‘Can my dog get the Coronavirus?’, a question many pet owners are wondering about nowadays. The media is flooding us with information on the new COVID-19 coronavirus, which can be dangerous especially for older people with reduced immunity. Lots of people wonder if the virus also poses a threat to our dogs. Today I will try to answer the most frequently asked questions. I will also describe several zoonoses or diseases that are transmitted from animals to humans. Dogs can infect us not only with some viruses but also with many bacteria, parasites and even fungi. I will also tell you about the diseases with which we can infect our domestic pooches. Let’s start with the most popular question lately.

Dog wearing mask face mask- source: https://www.abc.net.au/

Can a dog become infected with a coronavirus?

It’s good to know that there are many different coronaviruses that can attack both humans and other animals. Most viruses are species-specific. This means that canine viruses usually attack dogs and are not dangerous to humans and vice versa. However, there are cases when the same virus can be transmitted by different species. We are familiar with the SARS coronavirus (SARS-CoV), which appeared in China in 2002. It was detected not only in humans but also in ferrets, cats and civet. In 2012, the first infection with the MERS virus (MERS-CoV) was detected, which is also from the coronavirus family. Antibodies against this virus have been found in camels and bats. The latest coronavirus (SARS-CoV-2) appeared in 2019 in the Chinese city of Wuhan. This virus most likely came from an animal sold at a local food market and spread to humans.

African Civet (Civettictis civetta) — is a carnivorous mammal of the pus family, which may be the carrier of the SARS coronavirus — image source: AnimalSpot.net

Coronaviruses are a fairly large group of viruses of similar structure. Among them, we find viruses specific only to dogs. They usually attack the respiratory or digestive system of our pets. Unfortunately, we do not have an effective vaccine against coronaviruses and the diseases caused by them are usually treated symptomatically. Fortunately, the course of these diseases in most cases is quite mild. Puppies are most at risk from coronavirus infection. You should also be especially careful in places where there are a lot of dogs, e.g. in shelters, kennels or at exhibitions.

There is no evidence pets can be infected with coronavirus- source: www.hsdayton.org/coronavirus.

The World Health Organization (WHO) has until recently argued that there is no evidence that pets such as dogs can be infected with the SARS-CoV-2 virus. However, low virus levels were detected in Hong Kong last week in a dog infected with the coronavirus. The dog has no disease symptoms. Despite this, he came to a two-week quarantine where further tests are carried out to check whether the dog is actually infected with the SARS-CoV-2 virus or if the samples were contaminated during collection.

Rabies

Although coronavirus is the most important media topic lately, it’s worth knowing that there are other, much more dangerous to humans, viral diseases transmitted by dogs. The most dangerous is rabies, which according to WHO kills around 60,000 people worldwide every year. Most deaths occur in Africa and Asia. Rabies is caused by a virus from the Rhabdoviridae family, the genus Lyssavirus excreted together with the saliva of sick animals. Infection usually occurs as a result of being bitten by a sick animal or licking damaged human skin. In addition to pets such as dogs and cats, rabies can also be spread by wild animals, including foxes, raccoon dogs, badgers, bats and other carnivores, as well as rodents and lagomorphs.

Rabies risk around the world — source: https://www.who.int/

Symptoms of the disease appear for several weeks and sometimes even several months after infection. In the first phase, there are general symptoms such as malaise, headache, anxiety or irritability. Sick animals often change their habits. They can, for example, change the way of life from day to night and vice versa. They also stop being sensitive to pain. In the next phase of the disease, paralysis results from encephalitis. There are disturbances of consciousness, convulsions, water disorder, photophobia, drooling and finally cardiac and respiratory arrest. Rabies is an extremely deadly and practically incurable disease. That is why prevention in the form of annual vaccinations is so important.

Bacterial diseases

A serious disease that can be transmitted from a dog to a human is caused by Mycobacterium tuberculosis tuberculosis. The symptoms of tuberculosis in dogs are not very characteristic, which makes diagnosis difficult. The dog becomes apathetic, gets tired faster, loses weight and may have elevated temperature. Tuberculosis usually affects the lungs, causing shortness of breath and causing a dry cough reflex. It can sometimes attack the dog’s digestive tract, causing diarrhea or vomiting. Dogs most often contract tuberculosis from other dogs, humans or by eating unpasteurized milk from sick cows.

Mycobacterium tuberculosis — source: https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis

Leptospirosis is another serious bacterial disease transmitted by dogs. Symptoms include high fever, headache, muscle and joint pain, chills, skin erythema, rash and conjunctival and throat mucosa. More complicated than the disease itself are complications after it, such as liver and kidney damage, inflammation of the heart muscle, blood vessels or acute respiratory failure. Human infections from a dog are rare but are possible after contact with the urine of an infected animal.

Leptospira interrogans — Source: https://microbewiki.kenyon.edu/

Another zoonosis is a Mediterranean fever also called Maltese fever, wave fever, Bang’s disease and goat’s milk fever. Brucella Canis causes the disease in dogs. The infection usually occurs sexually during mating or childbirth, when puppies can get infected from their mother. In dogs, this disease causes orchitis and epididymitis, and in bitches it causes miscarriages. In extreme cases, in both dogs and bitches, brucellosis can lead to infertility. Because this disease can occur in dogs with no visible symptoms, it is quite difficult to detect. A person can get it from a dog by ingestion, by eating foods contaminated with brucellosis sticks, as a result of skin injuries and respiratory tract. Symptoms in man include weakness, fever and muscle aches. In addition, skin rashes, headaches and joint pains, heart problems, mental disorders, testicular pains or even hearing loss may appear.

Brucella canis — Source: https://nl.wikipedia.org/wiki/Brucellose

Parasitic diseases

Some parasites in dogs can be dangerous to human health. These include roundworm dog Toxocara canis. Humans may be the accidental host of this nematode when he eats his eggs along with contaminated food or water. Roundworm larvae can be transmitted through the blood throughout the human body. The symptoms of roundworm infection can, therefore, be very different depending on where the parasite has settled. The disease can also be practically asymptomatic.

Toxocara canis — Source: https://en.wikipedia.org/wiki/Toxocariasis

Giardia lamblia is another parasite we can catch from a dog. This parasite in the small intestine of a dog may not give any specific disease symptoms, so it’s difficult to detect. Sometimes it can cause recurrent diarrhea, vomiting and lack of appetite. A person can become infected with a dog’s food. The most common symptoms of gardiosis in humans are diarrhea, nausea, lack of appetite, headache and general fatigue.

Giardia lamblia — source: https://en.wikipedia.org/wiki/Giardia_duodenalis

We can also get infected from the dog tapeworm or canine tapeworm. The first one is much more common in wild foxes than in our pets. Infection occurs by ingestion by swallowing the parasite’s eggs. In this way man becomes a random intermediate host. Tapeworm larvae usually nest in the liver or lungs, where they form fluid-filled cysts. An infected person may not know for many years that he is a carrier of the parasite. It is only when the cyst begins to compress on other organs that the first symptoms appear. In extreme cases, echinococcosis may cause anaphylactic shock and pose a serious threat to human life.

Echinococcus granulosus — source: https://commons.wikimedia.org/

On the other hand, canine tapeworm, fortunately, rarely attacks people. His eggs are eaten by fleas and they are most often a source of infection for the dog. A person can become infected with the tapeworm through the dog’s mouth by not observing the basic rules of hygiene. Small children playing with flea dogs are particularly vulnerable. Dog tapeworm disease is usually asymptomatic.

Microsporosis

Dogs can also infect us with various fungi, such as Microsporum canis, which causes a disease called microsporosis or microbial mycosis. These mushrooms multiply on the dog and get into its surroundings. Fungi spores can survive in exfoliated epidermis and hair for up to several months. Small-spore mycosis causes skin lesions mainly on the scalp. Sometimes lesions can also appear on smooth skin, mainly on the neck and torso. They usually have a round or oval shape. They are also characterized by different lengths of broken hair and are covered with finely flaky epidermis. Sometimes dermatological changes are also accompanied by itching of the skin. Micro-fungal infection is quite easily transmitted from dogs to humans. Children are most susceptible to infection. This disease, although chronic, even if untreated, disappears during puberty.

Microsporum canis — source: https://nl.wikipedia.org/wiki/Microsporum_canis

Diseases with which a person can infect a dog

It’s not just dogs that transmit all kinds of diseases to people. We can also pose a threat to our dogs’ health. Due to the species specificity of viruses, it does not happen that a dog is infected with human influenza virus. In rare cases, however, human mumps virus infection is reported. The symptoms of infection are similar to those found in humans. To protect your dog against infection with this virus, you should isolate him from people with mumps.

Staphylococcus aureau — source: pulmonologyadvisor.com

Much easier than viruses, we can infect our dog with bacterial diseases. A dangerous bacterium for both man and dog can be resistant to many antibiotics Staphylococcus aureau. Staph infection can lead to purulent diseases of many systems and organs. We can also infect our dog with streptococcal bacteria. They are a common cause of angina, or purulent inflammation of the throat and tonsils, mainly in children and adolescents. Streptococci called Streptococcus zooepidemicus is the cause of acute, often fatal, pneumonia in dogs mainly in shelters, kennels and other large clusters of dogs. A person can also spread a variety of parasites to a dog. An example would be scabies. Indirectly, we can also infect a dog with lice or fleas by moving them from sick to healthy dogs. The same applies to mycosis, which is easily infected by both dogs and humans.

Diseases transmitted by dogs to humans and vice versa are much more. That is why it is so important to maintain proper hygiene during contact with dogs and to use prophylaxis in the form of vaccinations. As soon as you notice any disturbing symptoms in your dogs, it is worth going to the vet as soon as possible and thoroughly examine the dog. Do not underestimate the disease symptoms that may appear in you.