Musculoskeletal

Question 1

Phenoxyacetic acid herbicides

Answer 1

• designed to kill plants, not restricted, large amounts or high concentration needed for issues to occur
• low toxicity in most animals, dogs are the most susceptible, silvex can cause problems at low doses in dogs
• effected animals are usually predisposed due to genetics or renal damage
• mechanism: unknown
• clinical signs: 1)GI effects (often only sign in the dog); 2)muscle effects including ataxia, rumen atony, hesitation to move (myotonia with serious toxicosis); 3)renal tubular degeneration; 4)hepatic necrosis
• diagnosis: GI/oral ulcers, liver damage, congestion of kidney/liver, enteritis
• treatment: decontamination, ion trapping to enhance excretion through kidneys if they are normal, good prognosis for treated animals

Question 2

Ergot Alkaloids

Answer 2

• in infected small grains, the seeds are replaced by sclerotia (looks like mouse poop); fescue infection is hard to detect and they are almost always infected
• mechanism: dopamine serotonin receptor agonist causing hallucinations, decreased prolactin secretion, smooth muscle contraction
• clinical signs: other slide
• diagnosing: sclerotia consumption
• treatment: remove source, prevent secondary infection, metoclopromide and domperidone to increase prolactin secretion/ normalize mare gestation

Question 3

Ergot alkaloids clinical signs

Answer 3

• cows: not eating while gaining weight, maintained winter coat, heat intolerance, fat necrosis, poor reproduction performance, necrotizing ergotism (lameness, gangrene, fescue foot)
• horse: abortion, weak foals, prolonged gestation
• pigs: infertility, early parturition, decreased milk production due to dopamine

Question 4

Ionophores

Answer 4

• forms lipid soluble complex facilitating ion transport: Ca and Na increase intracellularly leading to mitochondrial swelling
• used as an antibiotic to prevent bloat and coccidiosis
• toxicosis is usually a result of feed mixing errors; horses most susceptible while poultry most immune
• signs: 12-72hrs after ingestion, anorexia, colic, sweating, uncoordinated; cattle may also show diarrhea and respiratory distress. Poultry are down, dogs have paralysis
• diagnosis: increased muscular enzymes and myoglobinuria, Decreased K and Na. Muscle necrosis at necropsy
• treatment: change feed, supportive therapy, recovered animals may die from exercise intolerance. May give anti-oxidants

Question 5

Tetanus

Answer 5

• mostly effects cattle
• caused by spores in puncture wounds or ingested
• mechanism: block GABA release and glycine resulting in overstimulation of muscles and stiffness
• clinical signs: stiff, not moving, lock jaw, twitching, bloat, spasm, death
• treatment: antitoxin but only on very early stages, supportive therapy, poor prognosis

Question 6

Ventilators muscle paralysis

Answer 6

-botulism, tetanus, snake venom, OPs, strychnine

Question 7

Respiratory center depression

Answer 7

-barbiturates, opiates, ethylene glycol, crude oil, hypnotics, tricyclics antidepressants