Spring Grass      

in The Valley of the Sun??

With all the rain we’ve had these last few months, our desert is looking pretty green.  Horses are typically discriminating eaters, and ingestion of toxic plants is not usually a worry.  However, horses raised in the desert don’t get a whole lot of fresh greens in the diet, and become much less discriminating over the green stuff. 

There are a few toxic plants that grow in our desert you should be aware of; Fiddleneck (Amsinckia), Bitter Rubberweed (Hymenoxys), Riddell groundsel (Senecio).  There are many other desert toxic plants, but these are the most common in the Valley. 

Fiddleneck is close to the ground and looks like a grass with a wide fuzzy blade, which later produces a stem with multiple small yellow flowers arranged in the shape of a neck of a fiddle.  Whole plant is hairy, leaves alternate. Flowers are orange to yellow and grow only on outside of fiddleneck.  All parts of the plant are toxic.

The Rubberweed and Groundsel are the short shrubs that produce the daisy-like yellow flowers that turn our hills yellow in the spring. 

All three of the above plants are toxic to the liver.  Your horse would need to eat these in high quantity before seeing acute signs of liver disease.  But do remember,  damage to the liver is accumulative over time and causes cirrhosis or scaring in the liver.  

The acute signs are typically low grade intermittent colic, and photosensitivity.  The photosensitivity is usually the tip off to the ingestion of this type of toxic plant, as the liver cannot completely detoxify the principal agent and the skin becomes sensitive to the sun and burns easily.  You may first notice a blistered muzzle or raised scabs in the white skin haired areas, like on the legs. 

Should you notice these signs in your horse, talk with your veterinarian.  Finally there are many other ornamental plants that are extremely toxic to horses, the most common being Oleander.  In many of these ornamental plants, the leaves remain toxic when dried, so take care to clean up any leaves that blow in your pasture from your yard or your neighbors. 

Link to poisonous plant and other toxin information http://www.aspca.org/pet-care/poison-control

Cheryl Rahal, DVM ACVIM - Published in Bridle & Bit                        www.bridleandbit.com - 2/24

Phone: 623-581-1558    Email: DesertHillsAnimalClinic@hotmail.com