Can animals catch the flu?

A single word answers to this question is YES. Yes even animals can get affected by this deadly virus, the influenza virus, from the orthomyxoviridae family. Several species are affected by the virus. Natural infection is seen among swine, ferrets, water birds, horses, dogs and seals.

Influenza or flu viruses are classified as influenza A, B, C which constitutes 3 separate genera, based upon the characteristics of nucleoprotein and matrix protein of these three; A has been subdivided on the basis of surface antigens, hemagglutinin, and neuraminidase. B and C are similarly designated but these are rare intratypic variations in B and none with C.

Animal flu viruses cause infection normally in animals, similarly as human flu virus causes infection in humans. The problem arises when these animal viruses infect the humans, and as humans have no immunity against these pathogens the occurrence of explosive pandemics may be anticipated.


It is an acute respiratory disease of pigs caused by influenza A virus. These are associated with high morbidity rates but lower mortality rates. The outbreaks in the swine occur in the winter months as in the case of humans.

Swine flu virus also constantly undergoes antigenic variations. 4 main strains- H1N1, H1N2, H3N2 and H3N1 are responsible for majority of cases. An important factor being that these strains are different from human strains. H1N1 and H3N2 are endemic strains. The pigs too have respiratory symptoms such as running nose, cough, associated with lethargy and decreased appetite. It spreads among the pigs through contact with infected mucous secretions much like in humans.


First seen in birds, now it has brought the humanity under its claws. Known to get transmitted from birds mostly chickens to human beings. It has proven to be very fatal for both the species. This is caused by avian influenza virus (A/H5N1) which naturally occurs in the birds. Wild birds carry the viruses in their intestines. This is highly contagious virus and in the process may affect domestic birds like chickens, ducks, geese and turkey.

These birds shed the virus in their body secretions and excreta. Coming in contact with the secretions or the excreta other birds may get infected. Direct contact with infected poultry or through contact with dirt on cages, water or food may cause infection.

Two main forms of disease occur according to virulence. Low pathogenic avian influenza (LPAI) may escape notice with only mild symptoms, whereas highly pathogenic avian influenza (HPAI) has a rapid spread, engulfing huge populations of birds in no time. This form affects multiple internal organs and has a high mortality rate in a short period of time.

A word of caution for all of us is that this strain has much affection for the human beings as we may get affected if proper precautions are not taken, which may lead to severe morbid conditions in humans. Fatal outcome as death in some cases is inevitable.


This form of animal flu affects the horses and mules. Symptoms similar to human flu are present like running nose, fever, loss of appetite and lethargy. Transmission is also similar through respiratory secretions. It is a cause of significant morbidity and mortality among these animals.


Recent researches say that canines also get affected by this deadly virus. H3N8 strain, which is not a human influenza virus, causes dog flu. Though with a low mortality, it is a morbid condition affecting a huge population with mild form of the disease. This particular strain causing dog flu was earlier reported to have infected horses causing equine flu.

Other animals like cats, primates and seals may also get infected by this virus and suffer from the illness. Also, there is every possibility of transmission of these animal influenza viruses to humans.

Thus it is not only the humans who get infected; several species of animals are also not spared from the clutches of this deadly virus.

Published by me in Helium under pen name Dev Senapati.