One strategy for the prevention of infection transmission between cats and people is to better educate people on the behaviour that puts them at risk for becoming infected.

Those at the highest risk of contracting a disease from a cat are those with behaviors that include: being licked, sharing food, sharing kithchen utensils, kissing, and sleeping with a cat. The very young, the elderly and those who are immunocompromised increase their risk of becoming infected when sleeping with their cats (and dogs). The CDC recommends that cat owners not allow a cat to lick your face because it can result in disease transmission. If someone is licked on their face, mucous membranes or an open wound, the risk for infection is reduced if the area is immediately washed with soap and water. Maintaining the health of the animal by regular inspection for fleas and ticks, scheduling deworming medications along with veterinary exams will also reduce the risk of acquiring a feline zoonosis.

Recommendations for the prevention of ringworm transmission to people include:

- regularly vacuuming areas of the home that pets commonly visit helps to remove fur or flakes of skin

- washing the hands with soap and running water after playing with or petting your pet.

- wearing gloves and long sleeves when handling cats infected with.

- disinfect areas the pet has spent time in, including surfaces and bedding.

- the spores of this fungus can be killed with common disinfectants like chlorine bleach diluted 1:10 (1/4 cup in 1 gallon of water), benzalkonium chloride, or strong detergents.

- not handling cats with ringworm by those whose immune system is weak in any way (if you have HIV/AIDS, are undergoing cancer treatment, or are taking medications that suppress the immune system, for example).

- taking the cat to the veterinarian if ringworm infection is suspected.

Advice often given includes:

- Avoid sharing clothing, sports equipment, towels, or sheets.

- Wash clothes in hot water with fungicidal soap after suspected exposure to ringworm.

- Avoid walking barefoot; instead wear appropriate protective shoes in locker rooms and sandals at the beach.

- Avoid touching pets with bald spots, as they are often carriers of the fungus.

Experimental infection in immunocompetent and immunocompromised mice has produced intestinal inflammation, altered bowel habits, lethargy and death. Chronic diarrhea has been reported in non-human higher primates.

no approved human vaccine exist against "Dermatophytosis". For horses, dogs and cats there is available an approved inactivated vaccine called "Insol Dermatophyton" (Boehringer Ingelheim) which provides time-limited protection against several trichophyton and microsporum fungal strains.

Humans contract "Blastocystis" infection by drinking water or eating food contaminated with feces from an infected human or animal. "Blastocystis" infection can be spread from animals to humans, from humans to other humans, from humans to animals, and from animals to animals. Risk factors for infection have been reported as following:

- International travel: Travel to less developed countries has been cited in development of symptomatic Blastocystis infection. A 1986 study in the United States found that all individuals symptomatically infected with "Blastocystis" reported recent travel history to less developed countries. In the same study, all hospital employees working in New York who were screened for "Blastocystis" were found to have asymptomatic infections.

- Military service: Several studies have identified high rates of infection in military personnel. An early account described infection of British troops in Egypt in 1916 who recovered following treatment with emetine. A 1990 study published in "Military Medicine" from Lackland AFB in Texas concluded symptomatic infection was more common in foreign nationals, children, and immunocompromised individuals. A 2002 study published in "Military Medicine" of army personnel in Thailand identified a 44% infection rate. Infection rates were highest in privates who had served the longest at the army base. A follow-up study found a significant correlation between infection and symptoms, and identified the most likely cause as contaminated water. A 2007 newspaper article suggested the infection rate of US military personnel returning from the Gulf War was 50%, quoting the head of Oregon State University's Biomedicine department.

- Consumption of Untreated Water (well water): Many studies have linked "Blastocystis" infection with contaminated drinking water. A 1993 study of children infected symptomatically with "Blastocystis" in Pittsburgh indicated that 75% of them had a history of drinking well water or travel in less developed countries. Two studies in Thailand linked "Blastocystis" infection in military personnel and families to drinking of unboiled and untreated water. A book published in 2006 noted that in an Oregon community, infections are more common in winter months during heavy rains. A research study published in 1980 reported bacterial contamination of well water in the same community during heavy rainfall. A 2007 study from China specifically linked infection with "Blastocystis sp. subtype 3" with drinking untreated water. Recreational contact with untreated water, for example though boating, has also been identified as a risk factor. Studies have shown that "Blastocystis" survives sewage treatment plants in both the United Kingdom and Malaysia. "Blastocystis" cysts have been shown to be resistant to chlorination as a treatment method and are among the most resistant cysts to ozone treatment.

- Contaminated Food: Contamination of leafy vegetables has been implicated as a potential source for transmission of "Blastocystis" infection, as well as other gastrointestinal protozoa. A Chinese study identified infection with "Blastocystis sp. subtype 1" as specifically associated with eating foods grown in untreated water.

- Daycare facilities: A Canadian study identified an outbreak of "Blastocystis" associated with daycare attendance. Prior studies have identified outbreaks of similar protozoal infections in daycares.

- Geography: Infection rates vary geographically, and variants which produce symptoms may be less common in industrialized countries. For example, a low incidence of "Blastocystis" infection has been reported in Japan. A study of individuals infected with "Blastocystis" in Japan found that many (43%, 23/54) carried "Blastocystis sp. subtype 2", which was found to produce no symptoms in 93% (21/23) of patients studied, in contrast to other variants which were less common but produced symptoms in 50% of Japanese individuals. Studies in urban areas of industrialized countries have found "Blastocystis" infection associated with a low incidence of symptoms. In contrast, studies in developing countries generally show "Blastocystis" to be associated with symptoms. In the United States, a higher incidence of "Blastocystis" infection has been reported in California and West Coast states.

- Prevalence over Time: A 1989 study of the prevalence of "Blastocystis" in the United States found an infection rate of 2.6% in samples submitted from all 48 states. The study was part of the CDC's MMWR Report. A more recent study, in 2006, found an infection rate of 23% in samples submitted from all 48 states. However, the more recent study was performed by a private laboratory located in the Western US, and emphasized samples from Western states, which have previously been reported to have a higher infection rate.

Research studies have suggested the following items are not risk factors for contracting "Blastocystis" infection:

- Consumption of municipal water near water plant (not a risk factor): One study showed that municipal water was free of "Blastocystis", even when drawn from a polluted source. However, samples taken far away from the treatment plant showed cysts. The researchers suggested that aging pipes may permit intrusion of contaminated water into the distribution system.

- Human-to-Human transmission among adults (not a risk factor): Some research suggests that direct human-to-human transmission is less common even in households and between married partners. One study showed different members of the same household carried different subtypes of Blastocystis.

Cryptosporidiosis is a parasitic disease that is transmitted through contaminated food or water from an infected person or animal. Cryptosporidiosis in cats is rare, but they can carry the protozoan without showing any signs of illness. Cryptosporidiosis can cause profuse, watery diarrhea with cramping, abdominal pain, and nausea in people. Illness in people is usually self-limiting and lasts only 2–4 days, but can become severe in people with weakened immune systems. Cryptosporidiosis (Cryptosporidium spp.) Cats transmit the protozoan through their feces. The symptoms in people weight loss and chronic diarrhea in high-risk patients. More than one species of this genus can be acquired by people. Dogs can also transmit this parasite.

Amphistomiasis in farm and wild mammals is due to infection of paramphistomes, such as the species of "Paramphistomum", "Calicophoron", "Cotylophoron", "Pseudophisthodiscus", etc. These are essentially rumen flukes, of which "Paramphistomum cervi" is the most notorious in terms of prevalence and pathogenicity. Infection occurs through ingestion of contaminated vegetables and raw meat, in which the viable infective metacercaria are deposited from snails, which are the intermediate hosts. The immature flukes are responsible for destroying the mucosal walls of the alimentary tract on their way to growing into adults. It is by this fervent tissue obliteration that the clinical symptoms are manifested. The adult flukes, on the other hand, are quite harmless, as they merely prepare for reproduction.

The zoonotic infection in human is caused by "G. discoides" and "W. watsoni" which are essentially intestinal flukes. The disease due to "G. discoides" is more specifically termed gastrodiscoidiasis. In their natural hosts such as pigs and monkeys, their infection in asymptomatic, but human infection is prevalent, by which they cause serious health problems, characterised by diarrhoea, fever, abdominal pain, colic, and an increased mucous production. In extreme situations such as in Assam, India, a number of mortality among children is attributed to this disease.

There are many public health strategies that can drastically limit the transmission of "A. cantonensis" by limiting contact with infected vectors. Vector control may be possible, but has not been very successful in the past. Education to prevent the introduction of rats or snail vectors outside endemic areas is important to limit the spread of the disease. There are no vaccines in development for angiostrongyliasis.

Transmission of the parasite is usually from eating raw or undercooked snails or other vectors. Infection is also frequent from ingestion of contaminated water or unwashed salad that may contain small snail and slugs, or have been contaminated by them. Therefore it is very important to avoid raw snails, wash and cook vegetables thoroughly, and avoid open water sources that may be contaminated.

Immunodeficiency or immunosuppression can be caused by:

- Malnutrition

- Fatigue

- Recurrent infections

- Immunosuppressing agents for organ transplant recipients

- Advanced HIV infection

- Chemotherapy for cancer

- Genetic predisposition

- Skin damage

- Antibiotic treatment leading to disruption of the physiological microbiome, thus allowing some microorganisms to outcompete others and become pathogenic (e.g. disruption of intestinal flora may lead to "Clostridium difficile" infection

- Medical procedures

- Pregnancy

- Ageing

- Leukopenia (i.e. neutropenia and lymphocytopenia)

The lack of or the disruption of normal vaginal flora allows the proliferation of opportunistic microorganisms and will cause the opportunistic infection - bacterial vaginosis.

The preventative measure of keeping cats inside in areas with high infection rates can prevent infection. Approved tick treatments for cats can be used but have been shown not to fully prevent tick bites.

The most often used treatments for cytauxzoonosis are imidocarb dipropionate and a combination of atovaquone and azithromycin. Although imidocarb has been used for years, it is not particularly effective. In a large study, only 25% of cats treated with this drug and supportive care survived. 60% of sick cats treated with supportive care and the combination of the anti-malarial drug atovaquone and the antibiotic azithromycin survived infection.

Quick referral to a veterinarian equipped to treat the disease may be beneficial. All infected cats require supportive care, including careful fluids, nutritional support, treatment for complications, and often blood transfusion.

Cats that survive the infection should be kept indoors as they can be persistent carriers after surviving infection and might indirectly infect other cats after being themselves bitten by a vector tick.

In 2016, thermography was used to identify and evaluate bumblefoot lesions in 67 captive penguins from three species.

Bumblefoot is a common infection for domesticated poultry and waterfowl such as chickens, ducks and quail. Due to constant walking on hard, rough, or sharp surfaces, birds can develop small wounds on the bottom of their feet. These wounds are very susceptible to infection by opportunistic bacterial pathogens, chiefly "Staphylococcus aureus". Treatment often requires opening the wound to drain the pus, soaking it in epsom salts, and antibiotic treatment and local application of the antiseptic pyodine as local dressing.

Organisms similar to "D. fragilis" are known to produce a cyst stage that is able to survive outside the host and facilitate infection of new hosts. However, the exact manner in which it is transmitted is not yet known, as the organism is unable to survive outside its human host for more than a few hours after excretion, and no cyst stage has been found.

Early theories of transmission suggested "D. fragilis" was unable to produce a cyst stage in infected humans, but some animal existed that in which it did produce a cyst stage, and this animal was responsible for spreading it. However, no such animal has ever been discovered. A later theory suggested the organism was transmitted by pinworms, which provided protection for the parasite outside the host. DNA has been detected in surface-sterilized eggs of "Enterobius vermicularis" eggs, thus suggesting the latter may harbor the former. Experimental ingestion of pinworm eggs established infection in two investigators. Numerous studies reported high rates of coinfection with helminthes. However, recent study has failed to show any association between "D. fragilis" infection and pinworm infection. Parasites similar to "D. fragilis" are transmitted by consuming water or food contaminated with feces. The high rate (40%) of concomitant infection with other protozoa reported by at St. Vincent's Hospital, Sydney, Australia, supports the oral-fecal route of transmission.

Opportunistic infections caused by Feline Leukemia Virus and Feline immunodeficiency virus retroviral infections can be treated with Lymphocyte T-Cell Immune Modulator.

Amphistomiasis or paramphistomiasis (alternatively spelled amphistomosis or paramphistomosis) is a parasitic disease of livestock animals, more commonly of cattle and sheep, and humans caused by immature helminthic flatworms belonging to the order Echinostomida. The term amphistomiasis is used for broader connotation implying the disease inflicted by members of Echinostomida including the family Paramphistomidae/Gastrodiscidae (to be precise, the species "Gastrodiscoides hominis"); whereas paramphistomiasis is restricted to that of the members of the family Paramphistomatidae only. "G. discoides" and "Watsonius watsoni" are responsible for the disease in humans, while most paramphistomes are responsible in livestock animals, and some wild mammals. In livestock industry the disease causes heavy economic backlashes due to poor production of milk, meat and wool.

Rates of infection increase in conditions of crowding and poor sanitation, and are higher in military personnel and mental institutions.

The true extent of disease has yet to emerge, as most laboratories do not use techniques to adequately identify this organism. An Australian study identified a large number of patients, considered to have irritable bowel syndrome, who were actually infected with "Dientamoeba fragilis".

Although "D. fragilis" has been described as an infection "emerging from obscurity", it has become one of the most prevalent gastrointestinal infections in industrialized countries, especially among children and young adults. A Canadian study reported a prevalence of around 10% in boys and girls aged 11–15 years, a prevalence of 11.5% in individuals aged 16–20, and a lower incidence of 0.3–1.9% in individuals over age 20.

Toxoplasmosis is generally transmitted through the mouth when "Toxoplasma gondii" cysts are accidentally eaten. Congenital transmittance from mother to fetus can also occur. Transmission may also occur during the solid organ transplant process or hematogenous stem cell transplants.

Oral transmission may occur through:

- Ingestion of raw or partly cooked meat, especially pork, lamb, or venison containing "Toxoplasma" cysts: Infection prevalence in countries where undercooked meat is traditionally eaten has been related to this transmission method. Tissue cysts may also be ingested during hand-to-mouth contact after handling undercooked meat, or from using knives, utensils, or cutting boards contaminated by raw meat.

- Ingestion of unwashed fruit or vegetables that have been in contact with contaminated soil containing infected cat feces.

- Ingestion of contaminated cat feces: This can occur through hand-to-mouth contact following gardening, cleaning a cat's litter box, contact with children's sandpits; the parasite can survive in the environment for months.

- Ingestion of untreated, unfiltered water through direct consumption or utilization of water for food preparation.

- Ingestion of unpasteurized milk and milk products, particularly goat’s milk.

- Ingestion of raw seafood.

Cats excrete the pathogen in their feces for a number of weeks after contracting the disease, generally by eating an infected rodent. Even then, cat feces are not generally contagious for the first day or two after excretion, after which the cyst 'ripens' and becomes potentially pathogenic. In addition to cats, birds and mammals including human beings are also intermediate host of the spores and are involved in the transmission process. However the pathogenicity varies with the age and species involved in infection and the mode of transmission of "T. gondii".

Toxoplasmosis may also be transmitted through solid organ transplants. Toxoplasma-seronegative recipients who receive organs from recently-infected Toxoplasma-seropositive donors are at risk. Organ recipients who have latent toxoplasmosis are at risk of the disease reactivating in their system due to the immunosuppression occurring during solid organ transplant. Recipients of hematogenous stem cell transplants may experience higher risk of infection due to longer periods of immunosuppression.

Heart and lung transplants provide the highest risk for toxoplasmosis infection due to the striated muscle making up the heart, which can contain cysts, and risks for other organs and tissues vary widely. Risk of transmission can be reduced by screening donors and recipients prior to the transplant procedure and providing treatment.

The fundamental prevention strategy is hygiene and sanitation. Secondary measures include stricter meat-inspection standards, livestock confinement, health education, safe meat preparation, mass drug therapy, and identifying and treating human and pig carriers. Moreover, a high level of sanitation and prevention of human faecal contamination of pig feeds also plays a major role in prevention. Infection can be prevented with proper disposal of human faeces around pigs, cooking meat thoroughly and/or freezing the meat at −10 °C for 5 days. For human cysticercosis, dirty hands are attributed to be the primary cause, and especially common among food handlers.

Proper cooking of meat is an effective prevention. For example, cooking (56 °C for 5 minutes) of beef viscera destroys cysticerci. Refrigeration, freezing (−10 °C for 9 days) or long periods of salting is also lethal to cysticerci. Inspection of beef and proper disposal of human excreta are also important measures.

Congenital toxoplasmosis is a specific form of toxoplasmosis in which an unborn fetus is infected via the placenta. Congenital toxoplasmosis is associated with fetal death and abortion, and in infants, it is associated with neurologic deficits, neurocognitive deficits, and chorioretinitis. A positive antibody titer indicates previous exposure and immunity, and largely ensures the unborn fetus' safety. A simple blood draw at the first prenatal doctor visit can determine whether or not a woman has had previous exposure and therefore whether or not she is at risk. If a woman receives her first exposure to "T. gondii" while pregnant, the fetus is at particular risk.

Not much evidence exists around the effect of education before pregnancy to prevent congenital toxoplasmosis. However educating parents before the baby is born has been suggested to be effective because it may improve food, personal and pet hygiene. More research is needed to find whether antenatal education can reduce congenital toxoplasmosis.

For pregnant women with negative antibody titers, indicating no previous exposure to "T. gondii", serology testing as frequent as monthly is advisable as treatment during pregnancy for those women exposed to "T. gondii" for the first time dramatically decreases the risk of passing the parasite to the fetus. Since a baby's immune system does not develop fully for the first year of life, and the resilient cysts that form throughout the body are very difficult to eradicate with antiprotozoans, an infection can be very serious in the young.

Despite these risks, pregnant women are not routinely screened for toxoplasmosis in most countries, for reasons of cost-effectiveness and the high number of false positives generated; Portugal, France, Austria, Uruguay, and Italy are notable exceptions, and some regional screening programmes operate in Germany, Switzerland and Belgium. As invasive prenatal testing incurs some risk to the fetus (18.5 pregnancy losses per toxoplasmosis case prevented), postnatal or neonatal screening is preferred. The exceptions are cases where fetal abnormalities are noted, and thus screening can be targeted.

Pregnant women should avoid handling raw meat, drinking raw milk (especially goat milk) and be advised to not eat raw or undercooked meat regardless of type. Because of the obvious relationship between "Toxoplasma" and cats it is also often advised to avoid exposure to cat feces, and refrain from gardening (cat feces are common in garden soil) or at least wear gloves when so engaged. Most cats are not actively shedding oocysts, since they get infected in the first six months of their life, when they shed oocysts for a short period of time (1–2 weeks.) However, these oocysts get buried in the soil, sporulate and remain infectious for periods ranging from several months to more than a year. Numerous studies have shown living in a household with a cat is not a significant risk factor for "T. gondii" infection, though living with several kittens has some significance.

In 2006, a Czech research team discovered women with high levels of toxoplasmosis antibodies were significantly more likely to have baby boys than baby girls. In most populations, the birth rate is around 51% boys, but women infected with "T. gondii" had up to a 72% chance of a boy. In mice, the sex ratio was higher in early latent toxoplasmosis and lower in later latent toxoplasmosis.

Cytauxzoon felis is a protozoal organism transmitted to domestic cats by tick bites, and whose natural reservoir host is the bobcat. "C. felis" has been found in other wild felid species such as Florida bobcat, eastern bobcat, Texas cougar, and a white tiger in captivity. "C. felis" infection is limited to the family felidae which means that "C. felis" poses no zoonotic (transmission to humans) risk or agricultural (transmission to farm animals) risk. Until recently it was believed that after infection with "C. felis", pet cats almost always died. As awareness of "C. felis" has increased it has been found that treatment is not always futile. More cats have been shown to survive the infection than was previously thought. New treatments offer as much as 60% survival rate.

The drug of choice for the treatment of uncomplicated strongyloidiasis is ivermectin. Ivermectin does not kill the "Strongyloides" larvae, only the adult worms, therefore repeat dosing may be necessary to properly eradicate the infection. There is an auto-infective cycle of roughly two weeks in which Ivermectin should be re-administered however additional dosing may still be necessary as it will not kill "Strongyloides" in the blood or larvae deep within the bowels or diverticula. Other drugs that are effective are albendazole and thiabendazole (25 mg/kg twice daily for 5 days—400 mg maximum (generally)). All patients who are at risk of disseminated strongyloidiasis should be treated. The optimal duration of treatment for patients with disseminated infections is not clear.

Treatment of strongyloidiasis can be difficult and "Strongyloides" has been known to live in individuals for decades; even after treatment. Continued treatment is thus necessary even if symptoms resolve.

Because of the high cost of Stromectol, the veterinary formula Ivomec can be used. Government programs are needed to help citizens finance lifelong medication.

Clothes and sheets must be washed with enzyme washing powder and dried on hot daily.

A 2003 survey of diseases of the foot in 16 European countries found onychomycosis to be the most frequent fungal foot infection and estimates its prevalence at 27%. Prevalence was observed to increase with age. In Canada, the prevalence was estimated to be 6.48%. Onychomycosis affects approximately one-third of diabetics and is 56% more frequent in people suffering from psoriasis.

The total global infection is estimated to be between 40 and 60 million people. In the US, the incidence of infection is low, but 25% of cattle sold are still infected.

Disseminated strongyloidiasis occurs when patients with chronic strongyloidiasis become immunosuppressed. It presents with abdominal pain, distension, shock, pulmonary and neurologic complications and septicemia, and is potentially fatal. The worms enter the bloodstream from the bowel wall, simultaneously allowing entry of bowel bacteria such as "Escherichia coli". This may cause symptoms such as sepsis (bloodstream infection), and the bacteria may spread to other organs where they may cause localized infection such as meningitis.

Dissemination can occur many decades after the initial infection and has been associated with high dose corticosteroids, organ transplant, HIV, lepromatous leprosy, tertiary syphilis, aplastic anemia, malnutrition, advanced tuberculosis and radiation poisoning. It is often recommended that patients being started on immunosuppression be screened for chronic strongyloidiasis; however, this is often impractical (screen tests are often unavailable) and in developed countries, the prevalence of chronic strongyloidiasis is very small, so screening is usually not cost-effective, except in endemic areas.

It is important to note that there is not necessarily any eosinophilia in the disseminated disease. Absence of eosinophilia may indicate poor prognosis.