In cases of viral pneumonia where influenza A or B are thought to be causative agents, patients who are seen within 48 hours of symptom onset may benefit from treatment with oseltamivir or zanamivir. Respiratory syncytial virus (RSV) has no direct acting treatments, but ribavirin in indicated for severe cases. Herpes simplex virus and varicella-zoster virus infections are usually treated with aciclovir, whilst ganciclovir is used to treat cytomegalovirus. There is no known efficacious treatment for pneumonia caused by SARS coronavirus, MERS coronavirus, adenovirus, hantavirus, or parainfluenza. Care is largely supportive.

Most infections are mild and require no therapy or only symptomatic treatment. Because there is no virus-specific therapy, serious adenovirus illness can be managed only by treating symptoms and complications of the infection. Deaths are exceedingly rare but have been reported.

Treatment of bronchiolitis is usually focused on the symptoms instead of the infection itself since the infection will run its course and complications are typically from the symptoms themselves. Without active treatment half of cases will go away in 13 days and 90% in three weeks.

Measures for which the evidence is unclear include nebulized epinephrine, nasal suctioning, and nebulized hypertonic saline. Treatments which the evidence does not support include salbutamol, steroids, antibiotics, antivirals, chest physiotherapy, and cool mist.

Currently other medications do not yet have evidence to support their use. Ribavirin is an antiviral drug which does not appear to be effective for bronchiolitis. Antibiotics are often given in case of a bacterial infection complicating bronchiolitis, but have no effect on the underlying viral infection. Corticosteroids have no proven benefit in bronchiolitis treatment and are not advised. DNAse has not been found to be effective.

Normal surgical masks and N95 masks appear equivalent with respect to preventing respiratory infections.

ILI occurs in some horses after intramuscular injection of vaccines. For these horses, light exercise speeds resolution of the ILI. Non-steroidal anti-inflammatory drugs (NSAIDs) may be given with the vaccine.

Antibiotics are given to treat any bacterial infection present. Cough suppressants are used if the cough is not productive. NSAIDs are often given to reduce fever and upper respiratory inflammation. Prevention is by vaccinating for canine adenovirus, distemper, parainfluenza, and "Bordetella". In kennels, the best prevention is to keep all the cages disinfected. In some cases, such as "doggie daycares" or nontraditional playcare-type boarding environments, it is usually not a cleaning or disinfecting issue, but rather an airborne issue, as the dogs are in contact with each other's saliva and breath. Although most kennels require proof of vaccination, the vaccination is not a fail-safe preventative. Just like human influenza, even after receiving the vaccination, a dog can still contract mutated strains or less severe cases.

As of April 2020, there is no specific treatment for COVID-19. Research is, however, ongoing. For symptoms, some medical professionals recommend paracetamol (acetaminophen) over ibuprofen for first-line use. The WHO does not oppose the use of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen for symptoms, and the FDA says currently there is no evidence that NSAIDs worsen COVID-19 symptoms.

While theoretical concerns have been raised about ACE inhibitors and angiotensin receptor blockers, as of 19 March 2020, these are not sufficient to justify stopping these medications. Steroids, such as methylprednisolone, are not recommended unless the disease is complicated by acute respiratory distress syndrome.

Medications to prevent blood clotting have been suggested for treatment, and anticoagulant therapy with low molecular weight heparin appears to be associated with better outcomes in severe COVID‐19 showing signs of coagulopathy (elevated D-dimer).

Corticosteroids, such as dexamethasone and budesonide, have been shown to improve outcomes in children with all severities of croup. Significant relief is obtained as early as six hours after administration. While effective when given by injection, or by inhalation, giving the medication by mouth is preferred. A single dose is usually all that is required, and is generally considered to be quite safe. Dexamethasone at doses of 0.15, 0.3 and 0.6 mg/kg appear to be all equally effective.

Ribavirin is one medication which has shown good potential for the treatment of HPIV-3 given recent in-vitro tests (in-vivo tests show mixed results). Ribavirin is a broadscale anti-viral and is currently being administered to those who are severely immuno-compromised, despite the lack of conclusive evidence for its use. Protein inhibitors and novel forms of medication have also been proposed to relieve the symptoms of infection.

Furthermore, antibiotics may be used if a secondary bacterial infection develops. Corticosteroid treatment and nebulizers are also a first line choice against croup if breathing difficulties ensue.

Safe and effective adenovirus vaccines were developed for adenovirus serotypes 4 and 7, but were available only for preventing ARD among US military recruits, and production stopped in 1996. Strict attention to good infection-control practices is effective for stopping transmission in hospitals of adenovirus-associated disease, such as epidemic keratoconjunctivitis. Maintaining adequate levels of chlorination is necessary for preventing swimming pool-associated outbreaks of adenovirus conjunctivitis.

Children with croup are generally kept as calm as possible. Steroids are given routinely, with epinephrine used in severe cases. Children with oxygen saturations under 92% should receive oxygen, and those with severe croup may be hospitalized for observation. If oxygen is needed, "blow-by" administration (holding an oxygen source near the child's face) is recommended, as it causes less agitation than use of a mask. With treatment, less than 0.2% of children require endotracheal intubation.

Evidence does not support the general use of antibiotics in acute bronchitis. While some evidence suggests antibiotics speed up resolution of the cough by about 12 hours there is a greater risk of gastrointestinal problems and no change in longer term outcomes. Antibiotics use also leads to the promotion of antibiotic-resistant bacteria, which increase morbidity and mortality.

Research into potential treatments started in January 2020, and several antiviral drugs are in clinical trials. Remdesivir appears to be the most promising. Although new medications may take until 2021 to develop, several of the medications being tested are already approved for other uses or are already in advanced testing. Antiviral medication may be tried in people with severe disease. The WHO recommended volunteers take part in trials of the effectiveness and safety of potential treatments.

The FDA has granted temporary authorisation to convalescent plasma as an experimental treatment in cases where the person's life is seriously or immediately threatened. It has not undergone the clinical studies needed to show it is safe and effective for the disease.

While antibiotics with activity specifically against "M. pneumoniae" are often used (e.g., erythromycin, doxycycline), it is unclear if these result in greater benefit than using antibiotics without specific activity against this organism in those with an infection acquired in the community.

Antibiotics improve outcomes in those with bacterial pneumonia. Antibiotic choice depends initially on the characteristics of the person affected, such as age, underlying health, and the location the infection was acquired. In the UK, treatment before culture results with amoxicillin is recommended as the first line for community-acquired pneumonia, with doxycycline or clarithromycin as alternatives. In North America, where the "atypical" forms of community-acquired pneumonia are more common, macrolides (such as azithromycin or erythromycin), and doxycycline have displaced amoxicillin as first-line outpatient treatment in adults. In children with mild or moderate symptoms, amoxicillin remains the first line. The use of fluoroquinolones in uncomplicated cases is discouraged due to concerns about side-effects and generating resistance in light of there being no greater clinical benefit.

For those who require hospitalization and caught their pneumonia in the community the use of a β-lactam such as cephazolin plus macrolide such as azithromycin or a fluoroquinolones is recommended. The addition of corticosteroids also appears to improve outcomes.

The duration of treatment has traditionally been seven to ten days, but increasing evidence suggests that shorter courses (three to five days) are similarly effective. Recommendations for hospital-acquired pneumonia include third- and fourth-generation cephalosporins, carbapenems, fluoroquinolones, aminoglycosides, and vancomycin. These antibiotics are often given intravenously and used in combination. In those treated in hospital, more than 90% improve with the initial antibiotics.

Prevention is by not smoking and avoiding other lung irritants. Frequent hand washing may also be protective. Treatment of acute bronchitis typically involves rest, paracetamol (acetaminophen), and NSAIDs to help with the fever. Cough medicine has little support for its use and is not recommended in children less than six years of age. There is tentative evidence that salbutamol may be useful in those with wheezing; however, it may result in nervousness and tremors. Antibiotics should generally not be used. An exception is when acute bronchitis is due to pertussis. Tentative evidence supports honey and pelargonium to help with symptoms. Getting plenty of rest and fluids is also often recommended.

Antibiotics are ineffective, as SARS is a viral disease. Treatment of SARS is largely supportive with antipyretics, supplemental oxygen and mechanical ventilation as needed.

People with SARS must be isolated, preferably in negative pressure rooms, with complete barrier nursing precautions taken for any necessary contact with these patients.

Some of the more serious damage caused by SARS may be due to the body's own immune system reacting in what is known as cytokine storm.

As of 2017, there is no cure or protective vaccine for SARS that has been shown to be both safe and effective in humans. The identification and development of novel vaccines and medicines to treat SARS is a priority for governments and public health agencies around the world. MassBiologics, a non-profit organization engaged in the discovery, development and manufacturing of biologic therapies, is cooperating with researchers at NIH and the CDC developed a monoclonal antibody therapy that demonstrated efficacy in animal models.

Antibiotics do not help the many lower respiratory infections which are caused by parasites or viruses. While acute bronchitis often does not require antibiotic therapy, antibiotics can be given to patients with acute exacerbations of chronic bronchitis. The indications for treatment are increased dyspnoea, and an increase in the volume or purulence of the sputum. The treatment of bacterial pneumonia is selected by considering the age of the patient, the severity of the illness and the presence of underlying disease. Amoxicillin and doxycycline are suitable for many of the lower respiratory tract infections seen in general practice.

Most cases are self-limited and resolve themselves in a few weeks.

To increase their effectiveness, vaccines should be administered as soon as possible after a dog enters a high-risk area, such as a shelter. 10 to 14 days are required for partial immunity to develop. Administration of B. bronchiseptica and canine-parainfluenza vaccines may then be continued routinely, especially during outbreaks of kennel cough. There are several methods of administration, including parenteral and intranasal. However, the intranasal method has been recommended when exposure is imminent, due to a more rapid and localized protection. Several intranasal vaccines have been developed that contain canine adenovirus in addition to B bronchiseptica and canine-parainfluenza virus antigens. Studies have thus far not been able to determine which formula of vaccination is the most efficient. Adverse effects of vaccinations are mild, but the most common effect observed up to 30 days after administration is nasal discharge. Vaccinations are not always effective. In one study it was found that 43.3% of all dogs in the study population with respiratory disease had in fact been vaccinated.

Neuraminidase inhibitors may be used to treat viral pneumonia caused by influenza viruses (influenza A and influenza B). No specific antiviral medications are recommended for other types of community acquired viral pneumonias including SARS coronavirus, adenovirus, hantavirus, and parainfluenza virus. Influenza A may be treated with rimantadine or amantadine, while influenza A or B may be treated with oseltamivir, zanamivir or peramivir. These are of most benefit if they are started within 48 hours of the onset of symptoms. Many strains of H5N1 influenza A, also known as avian influenza or "bird flu", have shown resistance to rimantadine and amantadine. The use of antibiotics in viral pneumonia is recommended by some experts, as it is impossible to rule out a complicating bacterial infection. The British Thoracic Society recommends that antibiotics be withheld in those with mild disease. The use of corticosteroids is controversial.

Usually initial therapy is empirical. If sufficient reason to suspect influenza, one might consider oseltamivir. In case of legionellosis, erythromycin or fluoroquinolone.

A third generation cephalosporin (ceftazidime) + carbapenems (imipenem) + beta lactam & beta lactamase inhibitors (piperacillin/tazobactam)

Antibiotics are the treatment of choice for bacterial pneumonia, with ventilation (oxygen supplement) as supportive therapy. The antibiotic choice depends on the nature of the pneumonia, the microorganisms most commonly causing pneumonia in the geographical region, and the immune status and underlying health of the individual. In the United Kingdom, amoxicillin is used as first-line therapy in the vast majority of patients acquiring pneumonia in the community, sometimes with added clarithromycin. In North America, where the "atypical" forms of community-acquired pneumonia are becoming more common, clarithromycin, azithromycin, or fluoroquinolones as single therapy have displaced the amoxicillin as first-line therapy.

Local patterns of antibiotic-resistance always need to be considered when initiating pharmacotherapy. In hospitalized individuals or those with immune deficiencies, local guidelines determine the selection of antibiotics.

Antibiotics are commonly used to prevent secondary bacterial infection. There are no specific antiviral drugs in common use at this time for FVR, although one study has shown that ganciclovir, PMEDAP, and cidofovir hold promise for treatment. More recent research has indicated that systemic famciclovir is effective at treating this infection in cats without the side effects reported with other anti-viral agents. More severe cases may require supportive care such as intravenous fluid therapy, oxygen therapy, or even a feeding tube. Conjunctivitis and corneal ulcers are treated with topical antibiotics for secondary bacterial infection.

Lysine is commonly used as a treatment, however in a 2015 systematic review, where the authors investigated all clinical trials with cats as well as "in vitro" studies, concluded that lysine supplementation is not effective for the treatment or prevention of feline herpesvirus 1 infection.