Many cases of croup have been prevented by immunization for influenza and diphtheria. At one time, croup referred to a diphtherial disease, but with vaccination, diphtheria is now rare in the developed world.

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.

The disease may remain manageable, but in more severe cases, lymph nodes in the neck may swell, and breathing and swallowing are more difficult. People in this stage should seek immediate medical attention, as obstruction in the throat may require intubation or a tracheotomy. Abnormal cardiac rhythms can occur early in the course of the illness or weeks later, and can lead to heart failure. Diphtheria can also cause paralysis in the eye, neck, throat, or respiratory muscles. Patients with severe cases are put in a hospital intensive care unit and given a diphtheria antitoxin. Since antitoxin does not neutralize toxin that is already bound to tissues, delaying its administration is associated with an increase in mortality risk. Therefore, the decision to administer diphtheria antitoxin is based on clinical diagnosis, and should not await laboratory confirmation.

Antibiotics have not been demonstrated to affect healing of local infection in diphtheria patients treated with antitoxin. Antibiotics are used in patients or carriers to eradicate "C. diphtheriae" and prevent its transmission to others. The Centers for Disease Control and Prevention recommends either:

- Metronidazole

- Erythromycin is given (orally or by injection) for 14 days (40 mg/kg per day with a maximum of 2 g/d), or

- Procaine penicillin G is given intramuscularly for 14 days (300,000 U/d for patients weighing 10 kg); patients with allergies to penicillin G or erythromycin can use rifampin or clindamycin.

In cases that progress beyond a throat infection, diphtheria toxin spreads through the blood and can lead to potentially life-threatening complications that affect other organs, such as the heart and kidneys. Damage to the heart caused by the toxin affects the heart's ability to pump blood or the kidneys' ability to clear wastes. It can also cause nerve damage, eventually leading to paralysis. About 40% to 50% of those left untreated can die.

Quinvaxem is a widely administered pentavalent vaccine, which is a combination of five vaccines in one that protect babies from diphtheria, among other common childhood diseases. Diphtheria vaccine is usually combined at least with tetanus vaccine (Td) and often with pertussis (DTP, DTaP, TdaP) vaccines, as well.

There is low or very-low quality evidence that probiotics may be better than placebo in preventing acute URTIs. Vaccination against influenza viruses, adenoviruses, measles, rubella, "Streptococcus pneumoniae", "Haemophilus influenzae", diphtheria, "Bacillus anthracis", and "Bordetella pertussis" may prevent them from infecting the URT or reduce the severity of the 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.

The Centers for Disease Control describe protocol for treating sinusitis while at the same time discouraging overuse of antibiotics:

- Target likely organisms with first-line drugs: Amoxicillin, Amoxicillin/Clavulanate

- Use shortest effective course: Should see improvement in 2–3 days. Continue treatment for 7 days after symptoms improve or resolve (usually a 10–14 day course).

- Consider imaging studies in recurrent or unclear cases: some sinus involvement is frequent early in the course of uncomplicated viral URI

Treatment comprises symptomatic support usually via analgesics for headache, sore throat and muscle aches. Moderate exercise in sedentary subjects with naturally acquired URTI probably does not alter the overall severity and duration of the illness. No randomized trials have been conducted to ascertain benefits of increasing fluid intake.

Avian infectious bronchitis (IB) is an acute and highly contagious respiratory disease of chickens. The disease is caused by avian infectious bronchitis virus (IBV), a coronavirus, and characterized by respiratory signs including gasping, coughing, sneezing, tracheal rales, and nasal discharge. In young chickens, severe respiratory distress may occur. In layers, respiratory distress, nephritis, decrease in egg production, and loss of internal (watery egg white) and external (fragile, soft, irregular or rough shells, shell-less) egg quality are reported.

Prevention and control programs must take into account local understandings of people-poultry relations. In the past, programs that have focused on singular, place-based understandings of disease transmission have been ineffective. In the case of Northern Vietnam, health workers saw poultry as commodities with an environment that was under the control of people. Poultry existed in the context of farms, markets, slaughterhouses, and roads while humans were indirectly the primary transmitters of avian flu, placing the burden of disease control on people. However, farmers saw their free ranging poultry in an environment dominated by nonhuman forces that they could not exert control over. There were a host of nonhuman actors such as wild birds and weather patterns whose relationships with the poultry fostered the disease and absolved farmers of complete responsibility for disease control.

Attempts at singular, place-based controls sought to teach farmers to identify areas where their behavior could change without looking at poultry behaviors. Behavior recommendations by Vietnam's National Steering Committee for Avian Influenza Control and Prevention (NSCAI) were drawn from the FAO Principles of Biosecurity. These included restrictions from entering areas where poultry are kept by erecting barriers to segregate poultry from non-human contact, limits on human movement of poultry and poultry-related products ideally to transporters, and recommendations for farmers to wash hands and footwear before and after contact with poultry. Farmers, pointed to wind and environmental pollution as reasons poultry would get sick. NSCAI recommendations also would disrupt longstanding livestock production practices as gates impede sales by restricting assessment of birds by appearance and offend customers by limiting outside human contact. Instead of incorporating local knowledge into recommendations, cultural barriers were used as scapegoats for failed interventions. Prevention and control methods have been more effective when also considering the social, political, and ecological agents in play.

Avian influenza—known informally as avian flu or bird flu is a variety of influenza caused by viruses adapted to birds. The type with the greatest risk is highly pathogenic avian influenza (HPAI). Bird flu is similar to swine flu, dog flu, horse flu and human flu as an illness caused by strains of influenza viruses that have adapted to a specific host. Out of the three types of influenza viruses (A, B, and C), influenza A virus is a zoonotic infection with a natural reservoir almost entirely in birds. Avian influenza, for most purposes, refers to the influenza A virus.

Though influenza A is adapted to birds, it can also stably adapt and sustain person-to person transmission. Recent influenza research into the genes of the Spanish flu virus shows it to have genes adapted from both human and avian strains. Pigs can also be infected with human, avian, and swine influenza viruses, allow for mixtures of genes (reassortment) to create a new virus, which can cause an antigenic shift to a new influenza A virus subtype which most people have little to no immune protection.

Avian influenza strains are divided into two types based on their pathogenicity: high pathogenicity (HP) or low pathogenicity (LP). The most well-known HPAI strain, H5N1, appeared in China in 1996, and also has low pathogenic strains found in North America. Companion birds in captivity are unlikely to contract the virus and there has been no report of a companion bird with avian influenza since 2003. Pigeons do not contract or spread the virus.

Between early 2013 to early 2017, 916 lab-confirmed human cases of H7N9 were reported to the World Health Organization (WHO). On 9 January 2017, the National Health and Family Planning Commission of China reported to WHO 106 cases of H7N9 which occurred from late November through late December, including 35 deaths, 2 potential cases of human-to-human transmission, and 80 of these 106 persons stating that they have visited live poultry markets. The cases are reported from Jiangsu (52), Zhejiang (21), Anhui (14), Guangdong (14), Shanghai (2), Fujian (2) and Hunan (1). Similar sudden increases in the number of human cases of H7N9 have occurred in previous years during December and January.

During the latest outbreak of the disease (2004), several treatment methods were tested. Main treatment involved the administration of antibiotics, in some cases glucose solution or dietary mixtures were additionally supplemented. Outcome of the different treatment methods varied greatly. Especially the success of antibiotic treatment and a widespread use on wild animals remains a matter of debate.

Diphtheritic stomatitis is a recently discovered disease and has thus far been reported only in Yellow-eyed penguins ("Megadyptes antipodes"). Its symptoms are similar to human diphtheria and is characterized by infecteous lesions in the mouth area that impede swallowing and cause respiratory troubles. The infection is caused by "Corynebacterium amycolatum", an aerobic Gram-positive bacterium and mainly affects very young chicks. However, it seems likely that a triggering agent (e.g. a virus) might be involved in which renders the corynebacterium a secondary pathogen.

The disease has been a serious cause of mortality in the 2002 and 2004 Yellow-eyed penguin breeding seasons. It seems that only the New Zealand South Island and Stewart Island/Rakiura were affected.

Causes of upper airway obstruction include foreign body aspiration, blunt laryngotracheal trauma, penetrating laryngotracheal trauma, tonsillar hypertrophy, paralysis of the vocal cord or vocal fold, acute laryngotracheitis such as viral croup, bacterial tracheitis, epiglottitis, peritonsillar abscess, pertussis, retropharyngeal abscess, spasmodic croup. In basic and advanced life support airway obstructions are often referred to as "A-problems". Management of airways relies on both minimal-invasive and invasive techniques.

Airway obstruction may cause obstructive pneumonitis or post-obstructive pneumonitis.