Several drugs are effective for fascioliasis, both in humans and in domestic animals. The drug of choice in the treatment of fasciolosis is triclabendazole, a member of the benzimidazole family of anthelmintics. The drug works by preventing the polymerization of the molecule tubulin into the cytoskeletal structures, microtubules. Resistance of "F. hepatica" to triclabendazole has been recorded in Australia in 1995 and Ireland in 1998.

Praziquantel treatment is ineffective.

There are case reports of nitazoxanide being successfully used in human fasciolosis treatment in Mexico. There are also reports of bithionol being used successfully.

More recently, Mirazid, an Egyptian drug made from myrrh, has been investigated as an oral treatment of trematode-caused ailments including fascioliasis.

Nitazoxanide has been found effective in trials, but is currently not recommended. The life cycle includes freshwater snails as an intermediate host of the parasite.

Currently, no therapeutic drugs are prescribed for the disease. Therefore, prevention is the sole mode of treatment. This disease can only be prevented by quarantining sick birds and preventing migration of birds around the house, causing them to spread the disease. Deworming of birds with anthelmintics can reduce exposure to the cecal nematodes that carry the protozoan. Good management of the farm, including immediate quarantine of infected birds and sanitation, is the main useful strategy for controlling the spread of the parasitic contamination. The only drug used for the control (prophylaxis) in the United States is nitarsone at 0.01875% of feed until 5 days before marketing. Natustat and nitarsone were shown to be effective therapeutic drugs. Nifurtimox, a compound with known antiprotozoal activity, was demonstrated to be significantly effective at 300–400 ppm, and well tolerated by turkeys.

The severe symptoms caused by the parasite can be avoided by cleansing the skin, surgery, or the use of anthelmintic drugs, such as diethylcarbamazine (DEC), ivermectin, or albendazole. The drug of choice is DEC, which can eliminate the microfilariae from the blood and also kill the adult worms with a dosage of 6 mg/kg semiannually or annually. A polytherapy treatment that includes ivermectin with DEC or albendazole is more effective than each drug alone. Protection is similar to that of other mosquito-spread illnesses; one can use barriers both physical (a mosquito net), chemical (insect repellent), or mass chemotherapy as a method to control the spread of the disease.

Mass chemotherapy should cover the entire endemic area at the same time. This will significantly decrease the overall microfilarial titer in blood in mass, hence decreasing the transmission through mosquitoes during their subsequent bites.

Antibiotic active against the Wolbachia symbionts of the worm have been experimented with as treatment. Wolbachia-free worms first become sterile, and later die prematurely.

Bacteremia should be treated for 2 weeks, meningitis for 3 weeks, and brain abscess for at least 6 weeks. Ampicillin generally is considered antibiotic of choice; gentamicin is added frequently for its synergistic effects. Overall mortality rate is 20–30%; of all pregnancy-related cases, 22% resulted in fetal loss or neonatal death, but mothers usually survive.

The main means of prevention is through the promotion of safe handling, cooking and consumption of food. This includes washing raw vegetables and cooking raw food thoroughly, as well as reheating leftover or ready-to-eat foods like hot dogs until steaming hot.

Another aspect of prevention is advising high-risk groups such as pregnant women and immunocompromised patients to avoid unpasteurized pâtés and foods such as soft cheeses like feta, Brie, Camembert cheese, and bleu. Cream cheeses, yogurt, and cottage cheese are considered safe. In the United Kingdom, advice along these lines from the Chief Medical Officer posted in maternity clinics led to a sharp decline in cases of listeriosis in pregnancy in the late 1980s.

There is no specific treatment for the condition.

Control may rely on boosting bird immunity, preventing group mixing and faecal spreading.

The best treatment for cutaneous leishmaniasis is not known. Treatments that work for one species of leishmania may not work for another; it is recommended that advice of a tropical medicine or geographical medicine specialist be sought. Ideally, every effort should be made to establish the species of leishmania by molecular techniques (PCR) prior to starting treatment. In the setting of a developing country, there is often only one species present in a particular locality, so it is usually unnecessary to speciate every infection. Unfortunately, leishmaniasis is an orphan disease in developed nations, and almost all the current treatment options are toxic with significant side effects. The most sound treatment for cutaneous leishmaniasis thus far is prevention.

- "Leishmania major" :"L. major" infections are usually considered to heal spontaneously and do not require treatment, but there have been several reports of severe cases caused by "L. major" in Afghanistan. In Saudi Arabia, a six-week course of oral fluconazole 200 mg daily has been reported to speed up healing. In a randomized clinical trial from Iran, fluconazole 400 mg daily was shown to be significantly more effective than fluconazole 200 mg daily in the treatment of cutaneous leishmaniasis.

- "Leishmania braziliensis" :Treatment with pentavalent antimonials or amphotericin is necessary, because of the risk of developing disfiguring mucocutaneous lesions.

- "Leishmania infantum" :"L. infantum" causes cutaneous leishmaniasis in southern France.

New treatment options are arising from the new oral drug miltefosine (Impavido) which has shown in several clinical trials to be very efficient and safe in visceral and cutaneous leishmaniasis. Recent studies from Bolivia show a high cure rate for mucocutaneous leishmaniasis. Comparative studies against pentavalent antimonials in Iran and Pakistan are also beginning to show a high cure rate for "L. major" and "L. tropica". It is registered in many countries of Latin America, as well in Germany. In October 2006 it received orphan drug status from the US Food and Drug administration. The drug is generally better tolerated than other drugs. Main side effects are gastrointestinal disturbances in the 1–2 days of treatment which does not affect the efficacy.

Secondary bacterial infection (especially with "Staphylococcus aureus") is common and may require antibiotics. Clinicians who are unfamiliar with cutaneous leishmaniasis may mistake the lesion for a pure bacterial infection (especially after isolation of "S. aureus" from bacterial skin swabs) and fail to consider the possibility of leishmaniasis.

The organism should be cultured and antibiotic sensitivity should be determined before treatment is started. Amoxycillin is usually effective in treating streptococcal infections.

Biosecurity protocols and good hygiene are important in preventing the disease.

Vaccination is available against "S. gallolyticus" and can also protect pigeons.

Prevention focuses on protecting against mosquito bites in endemic regions. Insect repellents and mosquito nets are useful to protect against mosquito bites. Public education efforts must also be made within the endemic areas of the world to successfully lower the prevalence of "W. bancrofti" infections.

Fasciolosis (also known as fascioliasis, fasciolasis, distomatosis and liver rot) is a parasitic worm infection caused by the common liver fluke "Fasciola hepatica" as well as by "Fasciola gigantica". The disease is a plant-borne trematode zoonosis, and is classified as a neglected tropical disease (NTD). It affects humans, but its main host is ruminants such as cattle and sheep. The disease progresses through four distinct phases; an initial incubation phase of between a few days up to three months with little or no symptoms; an invasive or acute phase which may manifest with: fever, malaise, abdominal pain, gastrointestinal symptoms, urticaria, anemia, jaundice, and respiratory symptoms. The disease later progresses to a latent phase with less symptoms and ultimately into a chronic or obstructive phase months to years later. In the chronic state the disease causes inflammation of the bile ducts, gall bladder and may cause gall stones as well as fibrosis. While chronic inflammation is connected to increased cancer rates, it is unclear whether fasciolosis is associated with increased cancer risk.

Up to half of those infected display no symptoms, and diagnosis is difficult because the worm eggs are often missed in fecal examination. The methods of detection are through fecal examination, parasite-specific antibody detection, or radiological diagnosis, as well as laparotomy. In case of a suspected outbreak it may be useful to keep track of dietary history, which is also useful for exclusion of differential diagnoses. Fecal examination is generally not helpful because the worm eggs can seldom be detected in the chronic phase of the infection. Eggs appear in the feces first between 9–11 weeks post-infection. The cause of this is unknown, and it is also difficult to distinguish between the different species of fasciola as well distinguishing them from echinostomes and "Fasciolopsis". Most immunodiagnostic tests detect infection with very high sensitivity, and as concentration drops after treatment, it is a very good diagnostic method. Clinically it is not possible to differentiate from other liver and bile diseases. Radiological methods can detect lesions in both acute and chronic infection, while laparotomy will detect lesions and also occasionally eggs and live worms.

Because of the size of the parasite, as adult "F. hepatica": or adult "F. gigantica:" 25–75×12 mm, fasciolosis is a big concern. The amount of symptoms depend on how many worms and what stage the infection is in. The death rate is significant in both sheep and cattle, but generally low among humans. Treatment with triclabendazole has been highly effective against the adult worms as well as various developing stages. Praziquantel is not effective, and older drugs such as bithionol are moderately effective but also cause more side effects. Secondary bacterial infection causing cholangitis has also been a concern and can be treated with antibiotics, and toxaemia may be treated with prednisolone.

Humans are infected by eating watergrown plants, primarily wild-grown watercress in Europe or morning glory in Asia. Infection may also occur by drinking contaminated water with floating young fasciola or when using utensils washed with contaminated water. Cultivated plants do not spread the disease in the same capacity. Human infection is rare, even if the infection rate is high among animals. Especially high rates of human infection have been found in Bolivia, Peru and Egypt, and this may be due to consumption of certain foods. No vaccine is available to protect people against "Fasciola" infection. Preventative measures are primarily treating and immunization of the livestock, which are required to host the live cycle of the worms. Veterinary vaccines are in development, and their use is being considered by a number of countries on account of the risk to human health and economic losses resulting from livestock infection. Other methods include using molluscicides to decrease the number of snails that act as vectors, but it is not practical. Educational methods to decrease consumption of wild watercress and other waterplants has been shown to work in areas with a high disease burden.

In some areas special control programs are in place or have been planned. The types of control measures depend on the setting (such as epidemiologic, ecologic, and cultural factors). Strict control of the growth and sale of watercress and other edible water plants is important. Individual people can protect themselves by not eating raw watercress and other water plants, especially from endemic grazing areas. Travelers to areas with poor sanitation should avoid food and water that might be contaminated (tainted). Vegetables grown in fields, that might have been irrigated with polluted water, should be thoroughly cooked, as should viscera from potentially infected animals.

Fascioliasis occurs in Europe, Africa, the Americas as well as Oceania. Recently, worldwide losses in animal productivity due to fasciolosis were conservatively estimated at over US$3.2 billion per annum. Fasciolosis is now recognized as an emerging human disease: the World Health Organization (WHO) has estimated that 2.4 million people are infected with "Fasciola", and a further 180 million are at risk of infection.

To date, no treatment has been proven to effectively reverse or prevent the progression of PAM. Lung transplantation is an option for end stage disease, but is typically only recommended as a last resort when quality of life is significantly impaired.

Etidronate is a bisphosphonate and can reduce the formation of calcium hydroxyapatite crystals. It has led to clinical and radiological improvements in few cases.

Treatment for accidental ingestion of milk products by allergic individuals varies depending on the sensitivity of the person. An antihistamine such as diphenhydramine (Benadryl) may be prescribed. Sometimes prednisone will be prescribed to prevent a possible late phase Type I hypersensitivity reaction. Severe allergic reactions (anaphalaxis) may require treatment with an epinephrine pen, i.e., an injection device designed to be used by a non-healthcare professional when emergency treatment is warranted. A second dose is needed in 16-35% of episodes.

Histomoniasis (or histomonosis), also known as blackhead disease, is a commercially important disease of poultry, particularly of chickens and turkeys, due to parasitic infection of a protozoan, "Histomonas meleagridis". The protozoan is transmitted to the bird by the nematode parasite "Heterakis gallinarum". "H. meleagridis" resides within the eggs of "H. gallinarum", so birds ingest the parasites along with contaminated soil or food. Earthworms can also act as a paratenic host.

"Histomonas meleagridis" specifically infects the cecum and liver. Symptoms of the infection include depression, reduced appetite, poor growth, increased thirst, sulphur-yellow diarrhoea, listlessness, and dry, ruffled feathers. The head may become cyanotic (bluish in colour), hence the common name of the disease, blackhead disease; thus the name 'blackhead' is in all possibility a misnomer for discoloration. The disease carries a high mortality rate, and is particularly highly fatal in poultry, and less in other birds. Currently, no prescription drug is available to treat this disease.

Poultry (especially free-ranging) and wild birds commonly harbor a number of parasitic worms with only mild health problems from them. Turkeys are much more susceptible to getting blackhead than are chickens. Thus, chickens can be infected carriers for a long time because they are not removed or medicated by their owners, and they do not die or stop eating/defecating. "H. gallinarum" eggs can remain infective in soil for four years, a high risk of transmitting blackhead to turkeys remains if they graze areas with chicken feces in this time frame.

There is active research on trying oral immunotherapy (OIT) to desensitize people to egg allergens. A Cochrane Review concluded that OIT can desensitize people, but it remains unclear whether long-term tolerance develops after treatment ceases, and 69% of the people enrolled in the trials had adverse effects. They concluded there was a need for standardized protocols and guidelines prior to incorporating OIT into clinical practice. A second review noted that allergic reactions, up to anaphylaxis, can occur during OIT, and recommends this treatment not be routine medical practice. A third review limited its scope to trials of baked egg-containing goods such as bread or cake as a means of resolving egg allergy. Again, there were some successes, but also some severe allergic reactions, and the authors came down on the side of not recommending this as treatment.

Vaccination is the only known method to prevent the development of tumors when chickens are infected with the virus. However, administration of vaccines does not prevent transmission of the virus, i.e., the vaccine is not sterilizing. However, it does reduce the amount of virus shed in the dander, hence reduces horizontal spread of the disease. Marek's disease does not spread vertically. The vaccine was introduced in 1970 and the scientist credited with its development is Dr. Ben Roy Burmester and Dr. Frank J Siccardi. Before that, Marek's disease caused substantial revenue loss in the poultry industries of the United States and the United Kingdom. The vaccine can be administered to one-day-old chicks through subcutaneous inoculation or by "in ovo" vaccination when the eggs are transferred from the incubator to the hatcher. "In ovo" vaccination is the preferred method, as it does not require handling of the chicks and can be done rapidly by automated methods. Immunity develops within two weeks.

The vaccine originally contained the antigenically similar turkey herpesvirus, which is serotype 3 of MDV. However, because vaccination does not prevent infection with the virus, the Marek's disease virus has evolved increased virulence and resistance to this vaccine. As a result, current vaccines use a combination of vaccines consisting of HVT and gallid herpesvirus type 3 or an attenuated MDV strain, CVI988-Rispens (ATCvet code: ).

Mucocutaneous leishmaniasis is an especially disturbing form of cutaneous leishmaniasis, because it produces destructive and disfiguring lesions of the face. It is most often caused by "Leishmania braziliensis", but cases caused by "L. aethiopica" have also been described.

Mucocutaneous leishmaniasis is very difficult to treat. Treatment involves the use of pentavalent antimonial compounds, which are highly toxic (common side effects include thrombophlebitis, pancreatitis, cardiotoxicity and hepatotoxicity) and not very effective. For example, in one study, despite treatment with high doses of sodium stibogluconate for 28 days, only 30% of patients remained disease-free at 12 months follow-up. Even in those patients who achieve an apparent cure, as many as 19% will relapse. Several drug combinations with immunomodulators have been tested, for example, a combination of pentoxifylline (inhibitor of TNF-α) and a pentavalent antimonial at a high dose for 30 days in a small-scale (23 patients) randomised placebo-controlled study from Brazil achieved cure rates of 90% and reduced time to cure, a result that should be interpreted cautiously in light of inherent limitations of small-scale studies. In an earlier small-scale (12 patients) study, addition of imiquimod showed promising results which need yet to be confirmed in larger trials.

Crayfish plague, "Aphanomyces astaci", is a water mold that infects crayfish, most notably the European "Astacus" which dies within a few weeks of being infected. When experimentally tested, species from Australia, New Guinea and Japan were also found to be susceptible to the infection.

If a person becomes sick with swine flu, antiviral drugs can make the illness milder and make the patient feel better faster. They may also prevent serious flu complications. For treatment, antiviral drugs work best if started soon after getting sick (within two days of symptoms). Beside antivirals, supportive care at home or in a hospital focuses on controlling fevers, relieving pain and maintaining fluid balance, as well as identifying and treating any secondary infections or other medical problems. The U.S. Centers for Disease Control and Prevention recommends the use of oseltamivir (Tamiflu) or zanamivir (Relenza) for the treatment and/or prevention of infection with swine influenza viruses; however, the majority of people infected with the virus make a full recovery without requiring medical attention or antiviral drugs. The virus isolated in the 2009 outbreak have been found resistant to amantadine and rimantadine.

In the U.S., on April 27, 2009, the FDA issued Emergency Use Authorizations to make available Relenza and Tamiflu antiviral drugs to treat the swine influenza virus in cases for which they are currently unapproved. The agency issued these EUAs to allow treatment of patients younger than the current approval allows and to allow the widespread distribution of the drugs, including by volunteers.

Electrolytes may be replenished with oral rehydration supplements (typically containing salts sodium chloride and potassium chloride).

Appropriate antibiotics, such as ceftriaxone, may be given to kill the bacteria but are not necessary in most cases. Azithromycin has been suggested to be better at treating typhoid in resistant populations than both fluoroquinolone drugs and ceftriaxone. Antibiotic resistance rates are increasing throughout the world, so health care providers should check current recommendations before choosing an antibiotic.

As swine influenza is rarely fatal to pigs, little treatment beyond rest and supportive care is required. Instead, veterinary efforts are focused on preventing the spread of the virus throughout the farm, or to other farms. Vaccination and animal management techniques are most important in these efforts. Antibiotics are also used to treat this disease, which although they have no effect against the influenza virus, do help prevent bacterial pneumonia and other secondary infections in influenza-weakened herds.

Flock worker's lung can be prevented with engineering controls that protect workers from inhaling flock. Engineering controls to prevent inhalation of flock can include using guillotine cutters rather than rotary cutters, and ensuring that blades are sharp, since dull blades shear off more respirable particles. Flocking plants have also implemented medical surveillance programs for workers to diagnose cases at an earlier stage. Another technique for preventing flock worker's lung is cleaning the workplace with alternatives to compressed air in order to avoid resuspending particulates in the air.

Infection with "Aphanomyces astaci" is accompanied by few signs in its early stages, and the first indication of infection may be mortality. In the later stages, the muscles of the tail may appear whitened, or brownish-red where blood cells have encapsulated the hyphae. The effects of the neurotoxins in the oomycete can include appearing in daytime (crayfish are typically nocturnal) and a lack of coordination.

The aetiological agent of turkey viral hepatitis is a virus from the Picornaviridae family.

The disease is restricted to turkeys and is highly contagious but usually subclinical. It usually present in young birds under the age of 6 weeks.

It has been seen in Canada, Italy, the US and the UK.

Transmission is thought to be via the faeces and vertical transmission may also occur.

Flock worker's lung is generally treated by removing the individual from the environment where they are inhaling flock. Symptoms generally improve within days to weeks after stopping exposure. The benefits of glucocorticoid therapy are unclear.

Flock worker's lung may raise the risk for lung cancer, but the connection is a topic of research as of 2015. The disease can be subacute or develop over long periods of exposure.

The treatment of RM involves withdrawal of the offending nasal spray or oral medication. Both a "cold turkey" and a "weaning" approach can be used. Cold turkey is the most effective treatment method, as it directly removes the cause of the condition, yet the time period between the discontinuation of the drug and the relief of symptoms may be too long and uncomfortable for some individuals (particularly when trying to go to sleep when they are unable to breathe through their nose).

A benefit of the gradual “weaning” approach is that it helps preserve normal nasal airflow during the withdrawal process. United States Patent Number 5,988,870 was issued for a method and apparatus used to facilitate the precise titration and gradual withdrawal of decongestant nasal sprays containing addictive compounds. The system is sold under the brand name Rhinostat.

The use of over-the-counter (OTC) saline nasal sprays may help open the nose without causing RM if the spray does not contain a decongestant. Symptoms of congestion and runny nose can often be treated with corticosteroid nasal sprays under the supervision of a physician. For very severe cases, oral steroids or nasal surgery may be necessary.

For RM caused by topical decongestants, there are anecdotal reports of persons having success by withdrawing treatment from one nostril at a time.

A study has shown that the anti-infective agent benzalkonium chloride, which is frequently added to topical nasal sprays as a preservative, aggravates the condition by further increasing the rebound swelling.