Toxicology Brief: The 10 most common toxicoses in dogs - Veterinary Medicine
Medicine Center
DVM Veterinary Medicine Featuring Information from:


Toxicology Brief: The 10 most common toxicoses in dogs


Treating cholecalciferol-containing rodenticide ingestion requires close monitoring of the serum calcium and phosphorus concentrations and the renal function parameters for 72 to 96 hours. If hyperphosphatemia or hypercalcemia occurs, perform saline diuresis, and administer corticosteroids, furosemide, or phosphate-binding agents. Salmon calcitonin or pamidronate may also be needed. Pamidronate, a bisphosphonate used in people to treat hypercalcemia of malignancy, is a preferred agent in treating cholecalciferol toxicosis.7 Although expensive, a single dose of pamidronate is often sufficient to lower calcium concentrations enough that the animal can be returned home with minimal additional treatment.


Acetaminophen is available as tablets, capsules, or liquids, either alone or combined with other compounds such as opioids, aspirin, caffeine, and antihistamines. Acetaminophen toxicosis can result in hepatotoxicosis, methemoglobinemia, and facial and paw edema.9 Some dogs have developed transient keratoconjunctivitis sicca after ingesting acetaminophen doses well below the amounts previously considered to be of concern.1 Hepatotoxicosis can occur with doses of 50 to 100 mg/kg, and methemoglobinemia may occur in up to 75% of dogs ingesting 200 mg/kg.10

To treat acetaminophen toxicosis, initiate gastric decontamination procedures, and then administer a 5% N-acetylcysteine (NAC) solution. Administer 140 mg/kg NAC orally as a loading dose, followed by 70 mg/kg every six hours for at least seven doses.9 Although NAC is not labeled for intravenous administration, it can be given intravenously in life-threatening situations by using a bacteriostatic filter (0.2 m). Administer fluid therapy to maintain hydration; diuresis does not enhance acetaminophen elimination. Adjunctive therapies include administering ascorbic acid, which helps reduce methemoglobin to hemoglobin; cimetidine, which inhibits cytochrome P-450 oxidation in the liver and may help reduce acetaminophen metabolism; and S-adenosylmethionine in patients in which long-term treatment of hepatic injury is needed. Monitor serum chemistry profile parameters, and evaluate tear production and administer artificial tears and cyclosporine if needed.9 The facial and paw edema will resolve on its own, so corticosteroids and antihistamines are not indicated.

Pseudoephedrine-containing cold medications

Many cold medications contain pseudoephedrine, a sympathomimetic drug structurally similar to amphetamines. Pseudoephedrine ingestion can lead to dose-dependent stimulation of the cardiovascular system and the CNS. The most common clinical signs include agitation, hyperactivity, panting, hyperthermia, hypertension, tachycardia, head bobbing, or mydriasis. Ingesting as little as 10 to 12 mg/kg pseudoephedrine can cause life-threatening signs.11

Treatment includes gastric decontamination in asymptomatic animals, patient monitoring, and symptomatic care. Agitation and hyperactivity are best controlled with acepromazine; avoid diazepam because it may exacerbate the agitation. Administer phenobarbital or pentobarbital to control severe tremors and seizures, and give isoflurane in refractory cases. Fluid therapy enhances pseudoephedrine excretion and protects the kidneys from myoglobinuria, which can result from excessive shaking. Because of likely hypertension, do not exceed fluid rates of one and a half to two times the maintenance rate unless the dog is in shock or dehydrated. Closely monitor the heart rate and rhythm, and use beta-blockers, such as propranolol, if tachycardia is severe. Signs can persist for up to 72 hours.11


Click here