Horses years old are the most susceptible to infection. Two distinct influenza viruses have been found The definitive diagnosis is determined by identifying the virus in samples obtained from the nose and throat and from blood testing early in the course of the infection. There is no specific treatment for this infection. Rest and good nursing care may minimize the chance of secondary bacterial infection. If horses with EHVassociated nervous system disease remain able to walk, or are down for only 2 to 3 days, the outlook is usually favorable.
Intensive nursing care is necessary to avoid lung congestion, pneumonia, ruptured bladder, or intestinal problems. Recovery may be complete, but a small percentage of cases have nervous system damage. For prevention and control of EHV and EHVrelated diseases, management practices that reduce viral spread are recommended. New horses or those returning from other premises should be isolated for 3 to 4 weeks before mixing with resident horses, especially pregnant mares.
Pregnant mares should be maintained in a group away from the weanlings, yearlings, and horses out of training. In an outbreak of respiratory disease or miscarriage, affected horses should be isolated and appropriate measures taken for disinfection of contaminated premises.
Infected horses that show no clinical signs, which often includes older horses, act as carriers and can shed the virus. Fever may be the only abnormality observed. Other presenting signs may be combinations of fever and respiratory signs of nasal discharge and cough. Some horses have injected i. Horses with neurological disease caused by EHV-1 infection can quickly become uncoordinated and weak and have trouble standing. Difficulty urinating and defecating may also occur.
Often the rear limbs are affected more severely than the front, which results in dog-sitting and toe-dragging. Signs of brain dysfunction may occur as well, including extreme lethargy and a coma-like state.
When neurological disease occurs, it is typically 8 to 12 days after the primary infection involving fever. EHV-1 is commonly diagnosed from nasal swabs or blood samples by polymerase chain reaction PCR , which amplifies the DNA of the virus so that it can be detected. The laboratory recommends submitting both a nasal swab sample and a blood sample if possible. A nasal swab sample is the more desirable of the two if only one sample can be submitted.
Depending on when the sample is received, it is possible to receive same day delivery of test results. Since the positive predictive value the relationship between those individuals who test positive to the number of those testing positive that actually develop clinically significant disease of PCR-based tests for EHV-1 in asymptomatic horses is uncertain at this time, horses outside of quarantine areas or in unexposed stables should not be tested on a random basis.
The finding of a positive PCR test result in an asymptomatic horse does not provide conclusive evidence of either active infection or the potential for disease transmission, because low levels of nonreplicating virus may be the source of the viral DNA detected.
Therefore, the use of this technology as a screening tool for EHV-1 in clinically normal, nonexposed horses is considered inappropriate. Call your veterinarian. Isolate affected horse s from healthy horses.
Information for the Veterinarian. Using a 1 to 10 bleach ratio will neutralize the virus. Clinical signs may be non-specific and some horses may be non-clinical Fever Difficulty urinating Nasal discharge and cough Depression Head tilt Loss of tail tone Stumbling or weakness in the hind limbs, may progress to all limbs Down and unable to rise.
Additional Information. Hoof Care. Injuries and First Aid. Parasite Control. Preventative Care. Senior Horse Care. Tack and Apparel. Horse World. Barn Dogs. Ride along with a veterinarian.
Basic training with David O'Connor. Beyond the Saddle Podcast. The Jurga Report. Equine Disease Alerts.
0コメント