How Respiratory infection spread very fast in sheep ?

Respiratory Infection: It is an important medical problem of sheep and goats of all ages. In younger animals, various bacteria, viruses and parasites of the upper and lower respiratory tract are often involved in the development of respiratory infection.  In adults, these same disease – causing agents can create pneumonia. In sheep, a systemic virus known as Ovine Progressive Pneumonia virus (OPPV) can play an important role. In goats, a similar systemic virus, Caprine Arthritis and Encephalitis Virus (CAEV), can cause pneumonia. The word “systemic” means that OPPV and CAEV are viruses that can affect multiple organs, including the lungs. These viruses can also affect the brain, udder and the joints. In certain climates, parasites (worms) can travel from the gastrointestinal tract to the lungs, causing pneumonia.

What conditions increase the risk of Respiratory infection?

Below is a list of some of the conditions that can predispose sheep and goats to pneumonia.

All ages

• Overcrowded barns with poor ventilation
• Poor sanitation – urine and feces can release gases that harm the respiratory tract, and wet bedding can cause the animals to become chilled.
• Excessive dust
• Wide variation in environmental temperature (for example, cold nights followed by warm days)
• High humidity
• Stress: Transport, birthing, heavy milk production, weaning, and fighting other diseases are examples of stresses that can make sheep and goats more susceptible to pneumonia.

Young animals

• Failure to ingest adequate amounts of first milk (colostrum)
• Bottle feeding – if the nipple orifice on the bottle is cut too large, the milk in the bottle may flow into the lamb or kid’s mouth too quickly, causing it to run down the windpipe  into the lungs.

Adults

• Infection with the OPP or CAE virus

Is respiratory infection contagious?

Whether or not pneumonia is contagious – meaning capable of spreading from animal to animal – depends on the causative bacteria and / or viruses involved. Most viral diseases of the respiratory tract, including the OPP and CAE viruses, are contagious, and can spread among sheep and goats.

Certain bacteria can be transmitted from animal to animal in respiratory secretions, but many of these bacteria reside in low numbers in the mouth and nose of normal, healthy animals. 

When one or more of the causative conditions listed above occur, these  normal bacteria can increase in number rapidly and invade the lungs to cause pneumonia.

Therefore, pneumonia can be viewed as both a contagious disease and a disease that can arise from the animal’s own bacteria; the latter scenario is considered common when causative conditions are present.