I don't think dogs get pinworms, I've had dogs for most of my life. I think it's tapeworm, hookworm, roundworm and whipworms only. I will ask my good friend. She works with dogs.
30~80% is the number of humans having threadworm, not the percentage of people getting infestation in their organs whivh is rare.
Pet worms in human hosts
Animals have their own "animal-specific" forms of the roundworm, hookworm and whipworm. The transfer of these types of worms to humans is rare and is most likely to involve young children who play in areas such as parks and sandpits.
Domestic pets do not usually play a significant role in the transfer of threadworm / pinworm (Enterobius vermicularis). If the eggs become attached to the fur or hair of the pet then they can be transferred when they are patted. The risk of infestation, however, is no greater than touching any contaminated surface. Washing your hands after patting animals will reduce the risk of contamination
The roundworm eggs and hookworm larvae that are found in animal excretion can still infest humans. On rare occasions, the canine whipworm, Trichuris vulpis, which is host-specific to dogs, has also been discovered in humans. The roundworm and hookworm larvae will be unable to develop properly and complete their life cycle in a human.
Hookworms are host-specific but a human can still be infected if canine, Ancylostoma caninum, or feline, Ancylostoma braziliense, hookworm larvae penetrate the skin. When the larvae form of both cat and dog hookworms infect a human the result is known as "creeping eruption", cutaneous larva migrans (CLM) or dermal larval migrans (DLM). The larvae will be unable to complete their migratory cycle inside a human but they move just below the skin causing intense itching, inflammation and snake-like sores for weeks or even months until they eventually die.
Animal roundworms, or ascarids, such as Toxocara can infect humans but they will also fail to complete their life cycle, remaining as second stage juveniles. Toxocara canis in dogs and Toxocara cati in cats can infect humans via the faecal-oral route. The eggs are sticky and can collect on the hands or accumulate under fingernails, resulting in them being accidentally ingested by humans. The larvae that are supposed to mature in non-human hosts will hatch in the human intestine and can penetrate into other tissues or organs, causing complications.
Toxocara canis has a higher frequency than Toxocara cati. This is because almost all puppies are infected with toxocara at birth and it only as they become older that they develop an immunity to the parasite. Hormonal changes in the pregnant mother appears to stimulate the migration Toxocara canis larvae into the foetal puppies, where they mature within the bowel. Young puppies may continually contaminate their entire litter and have infective eggs stuck to their coats. Cats, on the other hand, often become infected with Toxocara cati by ingesting the larvae in the tissues of mice and other hosts.
Young puppies and kittens contribute most to the contamination of the soil with toxocara roundworm eggs, although the eggs must incubate for about two weeks in the soil before they become infective. The eggs themselves are hardy and can exist in the soil for a long time, even at temperatures of minus 25 degrees Celsius. Direct contact with an infected pet does not generally cause the infection to be transmitted to a human. The chances of an owner becoming infected with roundworms after being licked by a kitten or a puppy is actually very low but it is still a good idea to wash your hands and face after playing with a pet.
Human toxocarosis falls under the broader category of visceral larva migrans (VLM). It results from the migration of toxocara larvae within the human body. When a human ingests infective toxocara eggs it can cause VLM where the worm larvae, which is about half a millimetre in length, migrates through human tissue. This most commonly includes the lungs, the kidneys, the liver, and the brain. This damages the organs, creating nodules and causing an eosinophilic inflammatory response. The process may continue for a long time because the worms can live for several years. The symptoms of this disease are difficult to ascertain but can include an enlarged liver, weight loss, intermittent fever, a loss of appetite, or a cough. It may also result in asthma or pneumonia, especially if the worm larvae damage the lungs. VLM seems to be most common in young infants aged 1 to 4 years old.