Like people, horses become infected when their immune system gets compromised and when they are exposed to infectious agents thought about by carriers, vectors and even other infected animals. There are many common and uncommon equine infections and most of them, if not detected and treated early, will most likely lead to death or the development of more serious diseases. However, if proper diagnosis and management have been implemented, a horse suffering from infection will easily recover and will even be able to have immune defense against previous viral or bacterial infections the next time the same disease is encountered.
Equine infections are primarily caused by bacteria, viruses, parasites and even fungus. Moreover, the modes of transmission for these causative agents vary. There are infections that are transmitted via droplets and some may even be airborne, like respiratory infections. On the other hand, skin infections are usually transmitted by direct contact from an infected animal, while other infections are caused by ingesting contaminated feces. Some of the more serious equine infections are caused by vectors like mosquitoes and flies. Listed below are some types of equine infections classified according to whether the infection is found in the respiratory, urinary, nervous or other systems of the body.
Integument or Skin Infections
Equine infections found on the skin are typically characterized by constant itching and rubbing of the affected area, swinging of the horse's head from side to side, as well as flicking their ears. These infections are usually caused by parasites like lice and ticks, which feed on the horse's blood by biting or even burrowing on the skin surface, causing intestinal itching. Other skin equine infections are caused by fungus like ringworms. These are usually treated by special shampoos as well as other topical insecticidal agents. Moreover, keeping the stable clean and disinfected is important to kill all the parasitic and fungal causative agents.
These common equine infections are found on the throat, lungs and even lymph nodes. Coughing thick, yellow nasal discharges should give you clues that your horse is suffering from a respiratory infection. In some infections, such as strangles, lymph nodes are also enlarged and they cause the horse's breath to sound like it is being strangled. The management for this is incision and drainage of the affected nodes as performed by a qualified equine veterinarian. Antibiotic therapy is a must for bacterial infections, except for strangles where lymph nodes are already enlarged, while anti-viral agents are given for those caused by viruses. An example of viral infection of the respiratory system is the Equine Herpes Virus, which has two types, the EHV-1 and EHV-4. EHV-4 is less severe because it is limited to the respiratory system, where the EHV-1 causes problems outside the respiratory system like abortion and paralysis. These respiratory system equine infections are usually preceded by vaccination.
Nervous System Infections
In this type of equine infections, the brain is affected by viral or bacterial agents that may have been transmitted via inhalation and droplet or even thought about by vectors such as insects. One example of a nervous equine infection that is caused by a certain type of mosquito is encephalomyelitis. The symptoms are depression, high grade fever, uncoordinated gait, which advances to tremors and muscle weakness until the horse becomes completely paralyzed. The preventive management for this is vaccination and mosquito control. Another serious infection under this type is the West Nile Viral Infection. This is also transmitted by mosquitoes and could lead to coma in worst cases. Other horses do not show symptoms and recover on their own. Tetanus is also another infection under this type and it is preventable.
An example of this type is equine infectious anemia. Unfortunately, this is a fatal condition that is also vector-transmitted by mosquitoes and horse flies. The symptoms are sudden weight loss and fever, sweating, anemia, swelling of the limbs and generalized weakness. The sunset of this equine infection is fast and equine infectious anemia will only be suspected when the horse suddenly dies. Again, only preventive management is available for this condition, by vaccination and insect control.
Other infections include urinary tract infections as well as internal parasitic infections which involve worms and could be very common.