9 Diseases Dogs Can Transfer to Humans
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There are many diseases unique to the animal world which are not zoonotic, i.e. they can't be passed on to human beings. Your dog is able to carry certain diseases in this way. Sometimes, they may have a disease which both humans and dogs can contract, such as influenza. Although both canines and humans can get the flu, but they may not be able to get the same strain. This means that a sick dog can be well cared for without having to worry about its effects on us.
However, this isn't always the case and there are some which will be of concern. This is why AnimalWised brings you 9 diseases dogs can transfer to humans. In doing so, we can help protect the health of the human members of our family, at the same time best meeting the needs of our beloved canine members.
Intestinal parasites in dogs transmitted to humans
Of the number of diseases transmitted to humans from dogs, we begin with those caused by internal parasites. The majority of these are intestinal parasites which result in gastrointestinal disorders. However, they also include parasites such as heartworm which we will discuss in the next section. Intestinal parasites which can be transmitted from dogs to humans include:
- Roundworm: nematodes (the scientific name for roundworm) are one of the most widespread in dogs. Contagion is made possible through the placenta or breast milk of a mother dog to their young as well as being ingested from the ground or an infested animal carcass. These symptoms do no usually produce symptoms in healthy animals, but can cause vomiting and diarrhea in younger animals. In humans they are responsible for a disorder known as visceral larva migrans.
- Giardia: in an infestation of giardia, we can face protozoa responsible for symptoms such as profuse diarrhea. As always, an infestation will have a much greater impact on vulnerable animals such as those with a weakened immune system. It is believed that some genotypes are able to infest humans, although the most common cause in humans is due to contaminated water. Giardia is not always detected by examining a single stool sample, as excretion of them is intermittent. Samples, therefore, need to be taken over a few days.
- Tapeworms: there are many different varieties of tapeworm such as Dipylidium or Echinococcus. Fleas can transmit them to our dogs and they are then passed on to us. Children may become infected if they ingest flea eggs directly, often from eating something they shouldn't have. Infestation can come from ingesting eggs found in contaminated food, water or materials in a dog's environment. Taeniasis is a parasitic disease caused by infection of tapeworms and it can be asymptomatic. However, we can sometimes see proglottids around the anus area of the dog. These are broken segments of the tapeworm itself which look a lot like little grains of rice and often cause irritation. Echinococcosis is more common in dogs, but is rare in humans. If it is contracted by humans, it can result in hydatid cysts in the liver, lungs and brain.
The transmission of parasites from dogs to humans can occur in different ways. One of the most common is when the animal sniffs infested stool or other material, licks our hands and then we transfer it to our own mouths. If a dog infested with parasites defecates in the home or garden and the stool is left for some time, transfer can be made if we don't take the correct hygiene precautions. The same can happen when we take our dogs outside and they come in contact with infested material. In general, young children are most susceptible because they often put things in their mouths which they should not.
An up to date internal and external deworming schedule is the best way we can prevent infestation of these intestinal parasites. This is especially the case in vulnerable animals such as puppies. Because we love our dogs and want what's best for them, we need to take our dog to the vet to see what is the best deworming schedule in your area.
Filariasis in dogs and humans
Among communicable diseases between dogs and humans, we now highlight one which is becoming increasingly more important. Filariasis is a parasitic disease caused by a roundworm infection. In dogs, one particular type of roundworm called Dirofilaria immitis is known as heartworm and it is particularly dangerous as it can result in acute heart failure. The vector of this disease is the mosquito which transmits the heartworm eggs through its buccal (mouth) organs. This means a dog can become infested with a mosquito bite.
The filaria eggs will go through different stages of maturation until they end up lodging in the pulmonary arteries, the right side of the heart or in the venae cavae or hepatic veins. Additionally, females release into the blood microfilariae which can be passed on to another mosquito through a bite. This mosquito can then go on to infect more dogs.
As we can see, it is not possible for the dog to directly infect humans with the disease. However, we can become infested if the mosquito bites the dog and then transfers it to us. Thus, the dog acts as a reservoir for the disease. It is still relatively uncommon in humans and when it does occur, can be aysmptomatic. In dogs, however, heartworm can have dire consequences. This is because they can cause great damage to fundamental organs such as the heart, lungs or live, often resulting in death.
Infestation affecting the aforementioned vital organs in this way complicates treatment, especially when the worms are adult. This, once again, makes prevention so imperative. Finding out about your local mosquito rates and using protection against them is a good first start. You need to establish general guidelines which limit the exposure of your dog to potentially infectious insects. Internal anti-parasitics will also help to prevent the heartworm from completing their growth cycle. Deworming is important everywhere, but it takes on extra gravity when you live in an area where the disease is endemic such as the Spanish Canary Islands.
Skin diseases dogs can transmit to people
Scabies and ringworm are the most common skin diseases a dog can pass on to people. Both are well-known diseases and have obvious symptoms. Their characteristics include:
- Ringworm: also known as dermatophytosis, this disease is caused by a fungus (not an actual worm) which leads to circular patches on the skin. Spores from this fungus makes its way into a shared environment, infecting other dogs, other cats and even humans.
- Scabies: this is caused by a mite which burrows into the skin producing pruritus (pus) and areas which develop into wounds and cause alopecia. When the mite is in the environment, it can be very contagious especially with young or immunosuppressed dogs. Not all types of scabies are considered zoonoses. The most common one in dogs is known as sarcoptic mange and is cause by the mite Sarcoptes scabiei.
Preventing these diseases most commonly involves hygiene. Aspiration of areas, disinfection and regular washing of bedding and other material which comes in contact with the dog is vital. It is also important to keep the dog under close observation and take it to the veterinarian when you see any initial symptoms.
Rabies passed on from dogs to humans
Although the disease is practically eradicated in certain parts of the world such as Western Europe and North America, it is important to have it on this list of communicable diseases between dogs and humans. It still causes numerous human deaths in other parts of the world such as Asia and Africa. In Central and South America we can find high risk regions as well as those which have long established vaccination programs, making cases less likely.
Rabies is a viral disease which affects the brain. There is a vaccine which is the only way to fight it, both in terms of prevention and in fighting infection. Rabies affects the central nervous system and is fatal once symptoms appear. It is transmitted through saliva, so is passed on from dogs to humans through bites. If the anti-rabies medication is not given before the viral infection reaches the brain, the person or dog will die. This is why immediate action is so necessary.
Other diseases dogs can transmit to people
In addition to the above diseases, humans can also contract leishmaniasis or leptospirosis from dogs. Below we explain how:
Leishmaniasis in dogs and humans
This parasitic disease has considerable scope, hence its inclusion on this list. As with dirofilariasis, the dog dos not infect humans directly, but acts as a reservoir for the disease which is also transmitted by mosquito bites.
The symptoms are varied as it is divided into different types, but they all will form some sort of skin legion whether sores or ulcers. Treatment is essential as some forms of leishmaniasis can be fatal if left untreated. Vaccination against the disease is available, but prevention is the most important method of treatment.
Leptospirosis in dogs and humans
After reviewing the main pathologies which can be passed on from dogs to people, we end with leptospirosis. This is a bacterial disease for which there is no vaccine. The symptoms it produces are varied and can affect the digestive system, the liver or kidneys. The bacteria spreads through the urine of dogs and can remain in the ground for a period of months. Both other dogs and humans can be infected by coming in contact with this material. Infected material can also get into the body through an open wound or by drinking contaminated water. This disease requires veterinary treatment.
External parasites transmitted from dogs to humans
Fleas, ticks and live are all parasites which can easily transfer from a dog's skin to our own. Although a change of host does not necessarily constitute the spread of disease, these parasites can pass on disease through their bites, eggs and droppings. These disease may be some of the ones written about above, but they can also pass on diseases such as Lyme disease.
In general, these external parasites can lead to symptoms such as itching, rashes, open sores and even gastrointestinal problems. To avoid a possible infestation, we need to ensure the hygiene of our home and perform regular examinations of our dogs, especially if they have been somewhere where these parasites are likely to inhabit.
As we have seen, there are many diseases, infections, parasites and conditions which can be transmitted from canines to humans. To best prevent this from happening, there are some precautionary measures you can take:
- Internal and external deworming with regular top ups and knowing the particular hazards in your area.
- Maintaining an appropriate vaccination schedule.
- Avoid walking during times when mosquitoes are most prevalent.
- Regularly cleaning and disinfecting the places our dog likes to spend their time, especially if we have more than one.
- Washing our hands when we touch our dog and their toys, especially if we are eating. You have to be careful with children in particular when they handle dogs.
- Go the veterinarian for regular check ups.
This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.
If you want to read similar articles to 9 Diseases Dogs Can Transfer to Humans, we recommend you visit our Prevention category.