β οΈ Not veterinary advice. General educational information gathered from university extension services, USDA and veterinary associations. Conditions vary farm to farm. Always contact your veterinarian before deworming, supplementing minerals or changing feed, and call your vet immediately if you suspect poisoning.
Texas livestock guide
Region: Great Plains & Texas β Hot summers, cold north; dry west, humid east (east TX/OK behave like the Southeast).
π Cattle fever tick permanent quarantine zone along the Rio Grande β check movement rules with the Texas Animal Health Commission.
Horses in Texas
Common parasites
- Small strongyles (cyathostomins) β The main worm of adult horses; resistance to common dewormers is widespread. Use fecal egg counts with your vet rather than rotating on a calendar. (source)
- Large roundworms (ascarids) β Mainly foals and weanlings; heavy loads can cause impaction colic. (source)
- Tapeworms β Linked to some colics; usually treated once or twice a year. (source)
- Seasonal tip β In hot climates, transmission is lowest in mid-summer. (source)
Toxic plants & feeds
- Blister beetles in alfalfa β Alfalfa-growing region; inspect hay. (source)
- Locoweed β Rangeland; causes nervous signs and is addictive. (source)
- Yew (Taxus) β Ornamental shrub; a few mouthfuls can kill a horse within hours. Never toss hedge clippings into a pasture. (source)
- Ionophore feeds (monensin, lasalocid) β Cattle/poultry feeds and some mineral tubs are deadly to horses and donkeys. (source)
- Blister beetles in alfalfa hay β Crimped alfalfa can trap beetles (cantharidin); buy hay from a known source. (source)
- Lawn clippings β Ferment quickly and can cause colic or laminitis. (source)
Minerals
- Selenium β high in places β Some soils here are seleniferous and accumulator plants (e.g. milkvetch, princeβs plume) can cause selenium poisoning (hoof and mane/tail loss). Check before adding selenium. (source)
- Salt β Free-choice plain or trace-mineral salt for every horse.
- Balance to the forage β Grass hay alone often runs low in some trace minerals; a ration balancer is commonly used. Have hay tested if possible.
Donkeys in Texas
Common parasites
- Small strongyles and tapeworms β Same worms as horses; donkeys can carry heavy loads while looking fine. Use fecal egg counts. (source)
- Lungworm (Dictyocaulus arnfieldi) β Donkeys often carry it without coughing and can pass it to horses grazing with them. (source)
- Seasonal tip β In hot climates, transmission is lowest in mid-summer. (source)
Toxic plants & feeds
- Locoweed β Rangeland risk. (source)
- Yew, ionophore feeds β As deadly to donkeys as to horses. (source, source)
- Rich feeds and lush grass β Not a poison, but a major risk: donkeys easily become obese and develop laminitis or hyperlipemia.
Minerals
- Selenium β high in places β Seleniferous areas exist; do not supplement selenium without testing. (source)
- Salt and a low-calorie balancer β Donkeys usually need straw/low-sugar hay plus a vitaminβmineral balancer, not grain.
Goats in Texas
Common parasites
- Barber pole worm (Haemonchus contortus) β Blood-sucking stomach worm and a leading cause of goat deaths. Watch eyelid color (FAMACHA) and bottle jaw; resistance to all dewormer classes exists. (source, source)
- Coccidia β Kids 3 weeks to 6 months; diarrhea and poor growth, worse in crowded or wet pens. (source)
- Barber pole worm β Major problem in humid eastern Texas and Oklahoma. (source)
Toxic plants & feeds
- Locoweed, bitterweed β Range plants in Texas and the southern Plains. (source)
- Rhododendron, azalea, mountain laurel β Ornamental and wild shrubs that cause vomiting and collapse in goats. (source)
- Yew and cherry (wilted leaves) β Yew is deadly; wilted wild-cherry leaves release cyanide. (source)
- Avocado leaves β Toxic to goats (heart damage). (source)
- Excess grain β Overeating grain causes rumen acidosis (bloat, collapse).
Minerals
- Selenium β variable β Ranges from deficient to toxic within the region; test hay or blood before supplementing. (source, source)
- Use a GOAT mineral, not a sheep one β Goats need much more copper than sheep; sheep minerals are copper-restricted and can leave goats deficient (rough coat, swayback in kids). Never feed goat mineral to sheep β copper can poison them. (source, source)
- Loose mineral, free choice β Goats generally eat loose minerals better than blocks.
Cattle in Texas
Common parasites
- Brown stomach worm (Ostertagia ostertagi) β The most damaging cattle roundworm; Cooperia is also common. Young stock suffer most. (source)
- Flies and lice β Horn flies on pasture in summer; lice in winter. (source)
- Cattle fever ticks (Texas border) β A permanent quarantine zone runs along the TexasβMexico border; cattle there are inspected and treated. Report suspect ticks. (source)
- Liver fluke (Gulf Coast TX) β Coastal Texas. (source)
Toxic plants & feeds
- Larkspur, locoweed β Range plants; larkspur is a top killer of cattle in the West. (source)
- Yew β A leading cause of sudden death in cattle from tossed clippings. (source)
- Nitrate and prussic acid forages β Drought-stressed or frosted sorghum, sudangrass and johnsongrass, and some weeds; test suspect forage. (source)
- Excess grain β Grain overload (acidosis) or sudden diet changes.
Minerals
- Selenium β variable β Seleniferous soils and accumulator plants occur; chronic selenosis (lameness, hoof damage) is possible. Test forage. (source)
- Sulfates in water β High-sulfate water in parts of the Plains can cause polio (PEM) and block copper.
- Free-choice trace-mineral salt β Match the mineral to your forage and region; ask your extension agent or vet.
- Magnesium on lush pasture β Grass tetany risk in early spring on lush grass, especially older cows nursing calves; high-magnesium mineral is often used. (source)
Help in Texas
Suspect poisoning?
Remove the animal from the source, keep a sample of the plant or feed, and call your vet now.
- ASPCA Animal Poison Control Center β (888) 426-4435. 24/7, covers livestock and horses; a consultation fee may apply.
- Pet Poison Helpline β (855) 764-7661. 24/7; a fee applies.
Keep your herd's records in one place
Herd Papers keeps vaccines, Coggins, vet and farrier visits for each animal and reminds you before things come due.
Free to start. No card needed.
Last reviewed 2026-10-18. Regional summaries; your county extension office knows your area best.