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.

Prescribing antibiotics for laryngitis is not suggested practice. The antibiotics penicillin V and erythromycin are not effective for treating acute laryngitis. Erythromycin may improve voice disturbances after one week and cough after two weeks, however any modest subjective benefit is not greater than the adverse effects, cost, and the risk of bacteria developing resistance to the antibiotics. Health authorities have been strongly encouraging physicians to decrease the prescribing of antibiotics to treat common upper respiratory tract infections because antibiotic usage does not significantly reduce recovery time for these viral illnesses. Decreased antibiotic usage could also have prevented drug resistant bacteria. Some have advocated a delayed antibiotic approach to treating URIs which seeks to reduce the consumption of antibiotics while attempting to maintain patient satisfaction. Most studies show no difference in improvement of symptoms between those treated with antibiotics right away and those with delayed prescriptions. Most studies also show no difference in patient satisfaction, patient complications, symptoms between delayed and no antibiotics. A strategy of "no antibiotics" results in even less antibiotic use than a strategy of "delayed antibiotics".

There is no good evidence supporting the effectiveness of over-the-counter cough medications for reducing coughing in adults or children. Children under 2 years old should not be given any type of cough or cold medicine due to the potential for life-threatening side effects. In addition, according to the American Academy of Pediatrics, the use of cough medicine to relieve cough symptoms should be avoided in children under 4 years old, and the safety is questioned for children under 6 years old.

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

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.

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.

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.

No specific treatment is available, but antibiotics can be used to prevent secondary infections.

Vaccines are available (ATCvet codes: for the inactivated vaccine, for the live vaccine; plus various combinations).

Biosecurity protocols including adequate isolation, disinfection are important in controlling the spread of the disease.

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.

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.

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)

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.

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.

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.

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).

There is a vaccine for FHV-1 available (ATCvet code: , plus various combination vaccines), but although it limits or weakens the severity of the disease and may reduce viral shedding, it does not prevent infection with FVR. Studies have shown a duration of immunity of this vaccine to be at least three years. The use of serology to demonstrate circulating antibodies to FHV-1 has been shown to have a positive predictive value for indicating protection from this disease.

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.

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.

Post-viral cough can be resistant to treatment. Post-viral cough usually goes away on its own; however, cough suppressants containing codeine may be prescribed. A study has claimed theobromine in dark chocolate is more effective.

Oral antibiotics, rest, simple analgesics, and fluids usually suffice for complete resolution. However, those with other medical conditions, the elderly, or those with significant trouble breathing may require more advanced care. If the symptoms worsen, the pneumonia does not improve with home treatment, or complications occur, hospitalization may be required. Worldwide, approximately 7–13% of cases in children result in hospitalization, whereas in the developed world between 22 and 42% of adults with community-acquired pneumonia are admitted. The CURB-65 score is useful for determining the need for admission in adults. If the score is 0 or 1, people can typically be managed at home; if it is 2, a short hospital stay or close follow-up is needed; if it is 3–5, hospitalization is recommended. In children those with respiratory distress or oxygen saturations of less than 90% should be hospitalized. The utility of chest physiotherapy in pneumonia has not yet been determined. Non-invasive ventilation may be beneficial in those admitted to the intensive care unit. Over-the-counter cough medicine has not been found to be effective nor has the use of zinc in children. There is insufficient evidence for mucolytics.

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.

The best prevention against viral pneumonia is vaccination against influenza, adenovirus, chickenpox, herpes zoster, measles, and rubella.

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.

The cornerstone of therapy is reduction in immunosuppression. A recent surge in BKVAN correlates with use of potent immunosuppressant drugs, such as tacrolimus and mycophenolate mofetil (MMF). Studies have not shown any correlation between BKVAN and a single immunosuppressive agent but rather the overall immunosuppressive load.

- No guidelines or drug levels and doses exist for proper reduction of immunosuppressants in BKVAN

- Most common methods:

1. Withdrawal of MMF or tacrolimus

2. Replacement of tacrolimus by cyclosporine

3. Overall reduction of immunosuppressive load

4. Some cyclosporine trough levels reported to be reduced to 100–150 ng/ml and tacrolimus levels reduced to 3–5 ng/ml

- Retrospective analysis of 67 patients concluded graft survival was similar between reduction and discontinuation of agents.

- Single center study showed renal allografts were preserved in 8/8 individuals managed with reduction in immunosuppression while graft loss occurred in 8/12 patients treated with an increase in therapy for what was thought to be organ rejection.

Other therapeutic options include Leflunomide, Cidofovir, IVIG, and the fluoroquinolones. Leflunomide, a pyrimidine synthesis inhibitor is now generally accepted as the second treatment option behind reduction of immunosuppression.