Current Health Topics

Poisonous Plants of California

Horses, goats, sheep, and cattle can become ill or die if they eat from a poisonous plant. The best strategy is just to keep these plants out of reach. Here are photos, ID info, and poisoning symptoms for more than 30 hazardous ornamental and range plants.

Wildfire Smoke and Horses

Photo of wildfire smoke and horses

Wildfires are a common occurrence in California, especially during the hot summer and fall months and during a period of extended drought.  The past two years have been record-breaking years for wildfires, and there is concern regarding the potential effect of persistent smoke and related air pollution on horses.  Some information and suggestions are offered to serve as a general guide: Click here for information on wildfire smoke and its effect on horses.

Heat Advisory for Horses

Photo of horses getting hosed down

Many horse events are scheduled during the summer when it is hot.  We have created a poster that you can print out and hang in your or near your barn.  It includes some important tips to prevent heat-related problems in horses, along with a four-point assessment for determining your horse's condition before severe signs of heat exhaustion begins.  Click here for information on how to care for your horse in hot weather conditions.

Equine Herpesvirus

Photo of hand on horse's nose for EHV-1

For an exclusive section on EHV-1, including information on handling sick horses, diagnostic testing, control measures, etc., click here.

For up-to-date EHV-1 information and additional reading:

White Paper on Equine Herpes Myeloencephalopathy (EHM) prepared by the Center for Equine Health and the William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, 26 May 2011.

Phase II Recommendations for Horse Show/Event Managers Regarding EHV-1 Biosecurity Procedures issued by CDFA veterinarians and the faculty of the School of Veterinary Medicine, University of California, Davis, June 8, 2011.

How to Set Up a Disease Isolation Unit at a Farm or Horse Show, extracted from The Horse Report on Equine Herpesvirus-1 (April 2007).

For information on biosecurity measures and other practical information, see The Horse Report issue on Equine Herpesvirus-1.

A scientific review of recent developments in diagnostic procedures, treatment modalities, preventive measures and biosecurity protocols, published in 2009.



Laminitis in horses continues to be a significant health problem that can often lead to chronic lameness or premature death. Reported incidence varies from 7-34% of horses, and it has been identified as a top research priority among national research funding organizations and the American Association of Equine Practitioners. Consider that the laminae tissues are truly responsible for suspending the horse within the hoof capsule.

Laminitis is a syndrome in horses, with several underlying causes. This makes it difficult to study as there are likely different mechanisms of laminar damage. In addition, many horses suffer from sub-clinical laminitis, which goes undiagnosed over time and adds chronicity to the disease. Read about how CEH is working to enhance early diagnosis.

Equine Influenza

Equine influenza, caused by the orthomyxovirus equine influenza A type 2 (A/equine 2), is one of the most common infectious diseases of the respiratory tract of horses. It is endemic in the equine population of the United States and throughout much of the world. Read more about Equine influenza from AAEP here.

West Nile Virus


West Nile Virus (WNV) was a serious problem in California in 2007. The Center for Equine Health would like to remind horse owners to remain vigilant about keeping their horses' vaccinations current and to follow recommendations to prevent the spread of this mosquito-borne disease.