IMPORTANT: If you reside in a country where health product communications are restricted to health care professionals, and you are NOT a health care professional, please contact your veterinarian instead of reading the following information.

Optimizing Poultry Respiratory Health*

Respiratory diseases are one of the biggest health challenges faced by poultry producers worldwide, with numerous virulent pathogens, both viral and bacterial and often seen in combination, threatening the industry’s flocks. Severity of illness and death rates vary, but most of these diseases adversely affect productivity and performance of broiler, layer, or breeder birds. Moreover, by weakening birds’ respiratory systems and overall health, the diseases open the door to secondary infections such as E. coli, Pasteurella multocida (fowl cholera), and others. Collectively, respiratory pathogens have tremendous economic impact on the poultry industry.


Disease Management Approaches

While biosecurity and post-infection treatment play important roles, prophylactic vaccination has become the most important component of a program to optimize poultry respiratory health. Respiratory pathogens tend to be highly contagious—both horizontally via air, water, and the physical environment, and sometimes vertically to offspring—so disease control must include big-picture measures beyond treating affected individual birds.

Because many respiratory disorders present with similar clinical symptoms—coughing, sneezing, labored breathing, watery eyes, lethargy, etc.—accurate diagnosis is crucial for determining an appropriate selection of vaccines, especially in the presence of multiple pathogens. Live vaccines are often a first-line approach, particularly valuable for stimulating mucosal immunity—that is, local to the body’s mucous membranes, where respiratory pathogens easily enter—as well as systemic protection. Inactivated vaccines play an important role as well, especially as boosters for extending immunity in longer-lived birds. Some vector vaccines are also available.


Merial’s Solutions**

Our product portfolio includes a wide selection of vaccines of highly regarded efficacy and quality to help prevent and control the most important poultry respiratory diseases. Some of our top product brands in this area (often available across multiple regions**) include: 

  • AVINEW®, a live attenuated virus of Newcastle disease (also available in some markets** in NeO effervescent tablets)
  • BIORAL H120, a live attenuated virus of infectious bronchitis, H120 strain (also available in some markets** in NeO effervescent tablets)
  • GALLIVAC IB88, a live attenuated virus of infectious bronchitis, CR88121 strain (also available in some markets** in NeO effervescent tablets)
  • NEMOVAC, a live vaccine against avian metapneumovirus
  • TROVAC vector vaccines, against Newcastle disease and avian influenza
  • GALLIMUNE range, our line of inactivated vaccines against various respiratory pathogens (including many combination products)


And we offer numerous other vaccines for specific local needs. Brand and product availability varies from region to region, but we are always evolving our portfolio to address new challenges and changing epidemiologic conditions.

Our customer solutions also include the expertise of our Veterinary Services teams. These avian health specialists are closely attuned to regional epidemiologies and bring deep knowledge of diagnostic tools, vaccine compatibilities, and poultry business goals. Let us help you develop a customized vaccination program to optimize your flock’s respiratory health.


Key Poultry Respiratory Diseases*

IMPORTANT: Following are the top respiratory diseases that Merial focuses on, but be aware that we do not offer products for all these diseases in all regions, and we do offer local products for many other respiratory concerns. To learn about complete product options in your country, talk to your current Merial representative or contact us.


Newcastle Disease*

Caused by the Newcastle disease virus (NDV), this highly contagious respiratory disease infects primarily chickens but also other avian species such as turkeys, with younger birds most susceptible. There are numerous serotypes and strains ranging from low to high virulence, and causing a variety of respiratory symptoms as well as neurologic symptoms, poor egg production, and varying degrees of mortality.

NDV has been found in most regions of the world, but many areas have eradicated it. The disease can be controlled by vaccination, but strain diversity, local regulations, and other vaccination complexities require strategic selection of appropriate vaccines for a particular region, production site, and disease challenge. Merial has developed a deep and comprehensive portfolio of products to address the complexities of effective Newcastle disease vaccination.
Top Merial brands:** AVINEW®; GALLIMUNE range; TROVAC NDV; Merial Inc. vaccines (U.S. only)

More on our approach to Newcastle Disease


Avian Influenza*                

The term “avian influenza” (AI) actually encompasses a large number of viruses that infect domestic poultry as well as other species. AI viruses can be broadly divided into two categories based on pathogenicity. The “high-pathogenic” (HP) forms, which include most notably the H5 and H7 subtype strains, spread rapidly and cause severe disease and high mortality—leading to devastating economic losses to poultry businesses and often trade restrictions.

The “low-pathogenic” forms, including the H9N2 subtype strains, get much less media attention but still have significant economic impact. Although mortality rates are much lower and symptoms milder than HP AI, it still adversely affects bird productivity, especially when found in combination with other respiratory diseases. Merial is an industry leader in AI vaccination, providing effective products in adherence with local regulations on control of this public health and economic concern.
Top Merial brands:** TROVAC AIV H5; GALLIMUNE range

More on our approach to Avian Influenza


Infectious Bronchitis*

One of the most common avian respiratory pathogens, the infectious bronchitis virus causes acute, severe respiratory disease in chickens and is highly contagious within the production environment. The presence of other pathogens can increase disease severity. While mortality rates may be variable, infectious bronchitis greatly reduces performance across broiler, layer, and breeder birds, making it one of the most economically significant diseases in the poultry industry.

While some post-infection treatment can minimize complications, prophylactic vaccination is the best way to control the effects of infectious bronchitis. The virus has many distinct serotypes and strains, with many regional variations and new variants emerging frequently, so vaccines must be selected with close attention to local epidemiology. Merial’s portfolio includes a wide variety of options for vaccinating against this widespread industry concern.
Top Merial products:** BIORAL H120; GALLIVAC IB88; Merial Inc. vaccines (U.S. only)


Avian Rhinotracheitis & Swollen Head Syndrome*

The avian metapneumovirus infects many species, causing different respiratory diseases that result in significant economic loss. Turkeys are most affected by avian rhinotracheitis, an acute respiratory tract infection. In chickens the virus can cause swollen head syndrome, so-called for the characteristic sinus inflammation (among other symptoms); it also adversely affect egg production in layers and breeders. Mortality rates vary widely depending on the species, disease, and any secondary bacterial infections (often E. coli).

Both live and inactivated vaccines are used for disease control in endemic areas, and very early vaccination is recommended since inherited maternal antibodies are insufficient against the virus in young chicks. The usual approach is early vaccination with live vaccines followed by inactivated boosters for longer protection, and Merial’s portfolio includes such options for vaccinating against this widespread industry concern.
Top Merial products:** NEMOVAC


Infectious Laryngotracheitis*

Caused by a highly contagious herpesvirus, infectious laryngotracheitis is characterized by inflammation of the respiratory tract around the larynx and trachea, and often complicated by secondary bacterial infections. Outward respiratory symptoms can range from severe to more mild, and reduced egg production is common.

Mortality rates vary, and birds often recover, but they remain viral carriers for life. Thus vaccination in combination with good hygiene practices is important for ongoing control and reducing spread and future outbreaks. Merial’s portfolio includes a wide variety of options for vaccinating against this widespread industry concern.
Top Merial products:** BIO LARYNGO; LT BLEN; GALLIVAC LT



Among the class of mycoplasma bacteria found in poultry, Mycoplasma synoviae seems to be more and more involved in poultry respiratory disorders, lameness, and reduced or poor quality egg production. The most pathogenic of these bacteria, however, is Mycoplasma gallisepticum (MG), which can contribute to chronic respiratory disease in chickens, especially in combination with other pathogens—it is often seen in conjunction with E. coli infection and other respiratory viruses (e.g., Newcastle, infectious bronchitis). Clinical symptoms can vary from very mild to severe respiratory distress, and poor feed efficiency, growth, and egg production are often also seen. 

The disease caused by MG can run a prolonged course, and birds continue to be carriers even after treatment or recovery. Transmission can be both environmental and through offspring, so biosecurity and careful breeding practices are important in disease prevention. Vaccination can also play a role in disease protection, especially in layer birds. Merial’s portfolio includes a wide variety of options for vaccinating against this widespread industry concern.


Infectious Coryza*

A bacterial disease found only in chickens, infectious coryza primarily affects the nasal and sinus passages. It generally causes acute illness for a few weeks, but can sometimes become chronic. The disease most commonly affects layers and breeders, severely reducing or delaying egg production; occasionally it is seen in broilers.

Prevention is key in areas with known outbreaks. Both live viral and attenuated bacterin vaccines can be used to help control the disease, especially in areas of high incidence, as the bacteria spreads rapidly by air, water, and direct contact. Merial’s portfolio includes products for vaccinating against this widespread industry concern.
Top Merial products:** HAEMOVAX; BIO COR 3


*Merial produces and markets several vaccines against poultry respiratory diseases. However, be aware that NOT all aspects of the diseases mentioned on this page are addressed by a vaccine. Always consult the product label for exact vaccine indications.

**Many of Merial’s avian vaccines are only marketed and available in certain countries, sometimes under different trade names. Speak to your Merial representative or contact us to find out what’s available in your region.


To find out exactly which Merial avian products and vaccination equipment options are available in your region, talk to your Merial representative or contact us now.

Top Avian Health Concerns