Yes it can affect you seriously..

Those transmitted between animals and humans are called zoonoses and approximately 100 of these are known. A few representative ones are:

Salmonellosis Probably the most important public health — animal health problem, it is transmitted to humans either directly from animals or indirectly through contaminated products of animal origin — found in most warm-blooded and many cold-blooded vertebrates; food-producing animals frequently infected, and companion pets (dogs, cats) and other household pets (turtles, birds) have also been found to be carriers of these bacteria. The overall problem of salmonellae and pets is unknown, but authorities think that it is substantial. Acute gastroenteritis is most common human involvement, with anorexia (lack of appetite) and looseness of bowels often persisting for several days.

Leptospirosis Many veterinarians consider this a serious problem among pet (dog) and farm animals — human illness varies from inapparent to very serious, with liver and kidney damage — can be mis-diagnosed as other illnesses — agent shed in urine of infected animal, with transmission by direct contact or through a vehicle — canine illness varies considerably; chronic dog infection may remain unobserved by owner, while dog may continue excreting organism, maybe as long as 3 to 5 years.

Cat Scratch Fever This is a mysterious illness caused by scratching, biting, licking, etc. Many times cats, especially kittens, have inapparent infection and show no evidence of illness. This disease may cause prolonged disability; it is more serious than “mono,” for which it may be mistaken. There is no known effective treatment.

Toxoplasmosis This protozoan disease, originally associated with undercooked or raw meat, is now associated with the dog and cat. The cat has been specifically implicated because of a peculiarity in its digestive system which lets the agent begin a unique sexual cycle, and which results in an oocyst being eliminated in feces. The oocyst can be considered pollen-like and can easily become air-borne, with transmission possible by inhalation or ingestion. It appears that the agent may be responsible for many congenital malformations, with damage occurring during the final six months of pregnancy.

Psittacosis This disorder is related to sick or seemingly healthy birds. Household birds, especially parakeets and parrots have been the most frequent sources of the agent. Dogs and cats may also harbor the organism. Transmission is usually by inhalation of dust from dried droppings and feathers in an enclosed environment. The organism may be excreted from feces for long periods after recovery of the animal from clinical disease. Human disease may be severe (lung involvement), but is often mild.

Animal pets carry many other parasites (various worms) and vectors (fleas and ticks) which could cause disease. Because of their intimate association with humans, the dog and cat are probably more important as reservoirs than other animal pets.

Third, pet animals have been known to bite or scratch persons, even those known to them. Young dogs are more likely to bite than older ones. The bites and scratches can result in serious, painful injuries, which can also be contaminated by microorganisms; tetanus, rabies, pasteurellosis, and cat-scratch fever have occurred.

Dogs can carry a variety of germs that can make people sick. Some of these germs are common and some are rare. For example, puppies may pass the bacterium Campylobacter in their feces (stool). This germ can cause diarrhea in people. Puppies and some adult dogs often carry a variety of parasites that can cause rashes or illness in people. Less often, dogs in urban or rural areas can carry the bacterium Leptospira (lep-TO-spy-ruh). This germ causes the disease leptospirosis (lep-to-spi-roh-sis) in people and animals. Dogs can also carry rabies, a deadly viral disease. Rabies from dogs is rare in the United States.

Some people are more likely than others to get diseases from dogs. A person’s age and health status may affect his or her immune system, increasing the chances of getting sick. People who are more likely to get diseases from dogs include infants, children younger than 5 years old, organ transplant patients, people with HIV/AIDS, and people being treated for cancer. Special advice is available for people who are at greater risk than others of getting diseases from animals.

The pee and poop encourages bacteria growth.. if they are going on bedding and furniture you could end up with skin infections from sitting and laying on it.

How healthy do you think sh*t can be?

Sounds like the dogs just need some potty training.