Description    Organophosphates and carbamates are cholinesterase inhibitors that cause overstimulation of the parasympathetic nervous system. This is a common toxicosis in dogs and cats. A delayed-onset syndrome of paraparesis has been seen. Some sheep are more susceptible to organophosphate toxicosis due to low plasma A esterase levels. Chlorpyrifos (Dursban) is a chlorinated organophosphorus insecticide for which testosterone seems to potentiate clinical toxicity; the signs in chlorpyrifos-poisoned bulls can develop rapidly and resemble toxic rumenitis.
Species   Bovine, Canine, Equine, Feline, Caprine, Ovine, Porcine
Signs   Abdominal distention, Abnormal behavior, aggression, changing habits, Abnormal lung or pleural sounds, Abnormal proprioceptive positioning, Abnormal pupillary response to light, Abnormal upper airway breathing sounds, Agalactia, Anisocoria, Anorexia, Arrhythmia, Ataxia, Bloat in ruminants, Bloody stools, feces, hematochezia, Bradycardia, Circling, Cold skin, Colic, Coma, Constant or increased vocalization, Coughing, Cyanosis, Decreased borborygmi, Dehydration, Diarrhea, Dullness, Dysmetria, Dyspnea, Enophthalmos, Epistaxis, Excessive salivation, Excitement, Exercise intolerance, Fecal incontinence, Fever, Generalized lameness or stiffness, Generalized weakness, Hyperesthesia, Hypothermia, Inability to stand, Increased borborygmi, Increased frequency of urination, Increased respiratory rate, Lacrimation, Melena or occult blood in feces, stools, Miosis, Mucoid nasal discharge, Mucous, mucoid stools, feces, Mydriasis, Neck weakness, Nystagmus, Opisthotonus, Pale, Paraparesis, Polydipsia, Polyuria, Prolonged capillary refill time, Reluctant to move, Rumen hypomotility or atony, Seizures or syncope, Stiffness or extended neck, Sudden death, Sweating, Tachycardia, Tenesmus, Tetany, Tetraparesis, Tongue protrusion, Trembling, Tremor, Underweight, poor condition, thin, emaciated, unthriftiness, ill thrift, Urinary incontinence, Vomiting or regurgitation, Weak pulse, Weakness of one hindlimb, Weight loss
References   Santifort KM. Pyridostigmine bromide intoxication in two domestic cats. Vet Rec Case Reports 2018;6:e000596 [Web Reference]
Calzetta L. Geographical characteristics influencing the risk of poisoning in pet dogs: Results of a large population-based epidemiological study in Italy. Vet J 2018;Apr [Web Reference]
Nagy AL. Long-established and emerging pesticide poisoning in horses. Equine Vet Educ 2018;Jan [Web Reference]
Tinson E., A suspected case of intermediate syndrome in a dog with carbamate toxicosis. Aust Vet J 2017;95:201 [Web Reference]
Niles GA. Toxicoses of the Ruminant Nervous System. Vet Clin North Am Food Anim Pract 2017;33:111 [Web Reference]
Shaw EC. Delayed neuropathy in pigs induced by isofenphos. Vet Rec 1995;136:95 [Web Reference]
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