Sunday, 3 December 2017

All About ... Viruses

Viruses can infect every type of living thing including flowering plants, mammals and bacteria! 

Like bacteria they come in a variety of different shapes, including helical, envelopeand even more complex.  Viruses are smaller in size than bacteria (about 1% of the size on average).  The largest being pox viruses which are about the same size as bacteria. 

Each virion (virus particle) is made up of:
·         a core: made up of 1 or 2 DNA or RNA molecules
·         a capsid: a protein coat which enloses the core, it protects the genetic material (DNA) and helps it transfer from host to host ie: spread
·         an envelope: only some viruses have this additional layer which surrounds the capsid

Viruses can only reproduce when inside a living cell and this will also cause damage to the cell.  The virus attaches to a 'receptor ' on the cell surface, different viruses can only attach to certain cells eg: flu virus attaches to the cells lining the lungs and airways.  The virus then 'injects' its RNA or DNA into the cell where it uses the enzymes to make new virus particles (replicate).  The number of virus particles will eventually kill the cell and they will then be free to move around the body infecting other cells.  

As the virus infects and kills more cells, symptoms will begin to appear and this will continue until the immune system is able to fight the virus and overcome it. Some viruses will spread from horse to horse via biting flies or other biting insects.  Other viruses are spread through droplets from coughing or sneezing!  More seriously some viruses are airborne!

Many viruses can be dealt with by the immune system.  Vaccinations (before the horse contracts the virus) can help the immune system recognises the virus more quickly and so overcome it more quickly but antibiotics DON'T work on viruses.

Some viruses will lie dormant within the body and this can also help the horse develop immunity.  Viruses are usually 'host specific' so we can't catch horse flu, however, Rabies is an important exception and can transfer from species to species.

UK Equine Viruses include:
·         Equine Influenza
·         Equine Herpes Virus
·         Equine Infectious Anaemia

Did you see Wednesday's video ' Top Tips for Handling Horses'  on my You Tube channel?   
Horse Life and Love.  Please check it out and SUBSCRIBE.

You can also follow me on Facebook, Instagram and Twitter for updates on Chesney, Basil, Tommy and Daisy.

Until next time!

No comments:

Post a Comment