Nutritional Disorders: Poisonings (often cause signs of neurological disorders)
Plant Poisonings
- most plant poisonings are characterized by signs such as:
- sudden death
- laboured or very rapid breathing
- frothing at the mouth and excessive salivation, weakness, inability to stand
- convulsions or erratic behaviour, greenish saliva (vomiting)
- coma
- other plants (e.g. St. John’s wort, trefoil, certain clovers) cause animals to become sensitive to light (skin not covered by wool is burnt, inflammation and eventually sloughs)
- dark skinned sheep less affected than light skinned sheep
- red clover may cause infertility in ewes if fed during the breeding season
Cause/Transmission
- plant poisoning is not likely to occur on cultivated grounds or well managed pasture.
- most poisonous plants are unpalatable and livestock rarely eat them when other forage is abundant.
- More prone to eat poisonous plants when other plants are not available (in the spring and fall, during a drought or on an overgrazed pasture).
Treatment
- treatments generally ineffective by the time the sheep is found
- sheep affected with signs of light sensitivity should be removed from vegetation
- provide sheds or shade is available
- if severe, burned areas can be treated with antibiotic ointments
Prevention
- prevention much more effective than treatment
- don’t overgraze pastures
- have plenty of drinking water, calcium, phosphorous and mineral mix available at all times to prevent depraved appetites.
- manage pastures to discourage weeds
Nitrate poisoning
- animals fed heavily fertilized immature crops
- acute cases: increased heart rate, mucous membranes are bluish (gums etc.), muscle tremours, coma, death
- chronic cases: reduced performance, decreased milk production, reproductive problems
Cause/Transmission
- nitrate altered to nitrite in blood stream, decreases oxygen transfer to cells
- increased risk during droughts or if plants are stressed (accumulation of nitrates in plant)
Treatment
- acute cases have a poor prognosis
- change diet for chronic cases
Prevention
- apply fertilizers at recommended rates
- consider testing forages
- monitor closely if decreased plant growth likely
Farm yard poisoning
- varies with cause
Cause/Transmission
- paint, batteries, smelters
- pesticide (incecticide, herbicide, rodenticide etc.)
Treatment
- varies with cause, contact your veterinarian
Prevention
- keep the barn yard, sheep pens, and pasture free of toxic materials
- prevent exposure to freshly paint
- clean up or fence off garbage sites that sheep may access.
Urea Poisoning
- affects animals being fed urea in diet
- uneasiness, tremors, excessive salivation, rapid breathing, uncoordinated, bloat.
Cause/Transmission
- improper mixing of urea supplement into a grain ration
- sudden increase in urea supplement in diet
- excess urea broken down into ammonia which is absorbed the bloodstream – as with nitrate poisoning
Treatment
- call a veterinarian to treat cases of urea toxicity
- as an emergency measure, vinegar may be administered as a drench - lowers rumen pH and neutralizes ammonia
Prevention
- follow label instructions when adding urea supplement to the diet
