Toxins
๐ Honeybee Venom (Apitoxin)
Toxic Components
Melittin (major peptide): causes membrane disruption, pain, hemolysis.
Phospholipase Aโ: hydrolyzes membrane phospholipids โ cell lysis, inflammation.
Hyaluronidase: promotes toxin spread through tissue.
Histamine, serotonin, kinins: cause vasodilation and pain.
Mechanism of Action / Pathophysiology
Local effects: pain, erythema, edema due to histamine and kinins.
Systemic effects (multiple stings):
Hemolysis and rhabdomyolysis โ hemoglobinuria/myoglobinuria โ renal injury.
Hypotension and shock due to histamine and melittin-induced vascular permeability.
Anaphylaxis (immune-mediated): rapid onset respiratory or cardiovascular collapse.
Target tissues
Cell membranes (melittin + phospholipase Aโ)
Vascular endothelium โ shock
Kidneys (secondary to pigment nephropathy)
๐ฟ Top Plant Toxins in Dogs
Plant | Toxic Principle | Mechanism / Pathophysiology |
|---|---|---|
Sago palm (Cycas revoluta) | Cycasin (hepatotoxin) | Causes centrilobular hepatic necrosis โ vomiting, icterus, coagulopathy. |
Lilies (Lilium, Hemerocallis) | Unknown nephrotoxin | Renal tubular necrosis โ acute kidney failure (especially cats; less so in dogs). |
Oleander, Foxglove | Cardiac glycosides | Inhibit Naโบ/Kโบ-ATPase โ arrhythmias, hyperkalemia. |
Ricinus communis (Castor bean) | Ricin | Ribosome inactivation โ inhibition of protein synthesis โ GI, liver, kidney damage. |
Grapes/Raisins | Unknown nephrotoxin | Proximal tubular necrosis โ acute renal failure. |
Autumn crocus (Colchicum autumnale) | Colchicine | Binds tubulin โ inhibits mitosis โ GI ulceration, bone marrow suppression. |
๐ซ Top Food Toxins in Dogs
Food | Toxic Principle | Pathophysiology / Mechanism |
|---|---|---|
Chocolate / Cocoa | Methylxanthines (theobromine, caffeine) | Inhibit phosphodiesterase โ โ cAMP, โ catecholamines โ tachycardia, CNS excitation, tremors. |
Xylitol | Artificial sweetener | Stimulates massive insulin release โ profound hypoglycemia; may cause acute hepatic necrosis. |
Onions / Garlic | Thiosulfates | Oxidative damage to erythrocytes โ Heinz body hemolytic anemia. |
Grapes / Raisins | Unknown | Acute tubular necrosis โ acute renal failure. |
Macadamia nuts | Unknown | Causes weakness, ataxia, hyperthermia, vomiting (non-fatal, self-limiting). |
๐งผ Top Cleaning Product Toxins
Type | Active Agents | Mechanism / Pathophysiology |
|---|---|---|
Bleach (sodium hypochlorite) | Corrosive alkali | Liquefactive necrosis of mucosa โ vomiting, esophageal burns, aspiration pneumonia. |
Phenolic disinfectants | Phenol compounds | Direct hepatotoxin and corrosive; causes CNS depression, liver necrosis. |
Cationic detergents (quaternary ammonium compounds) | Benzalkonium chloride, etc. | Caustic โ oral/dermal ulceration, respiratory distress if inhaled. |
Drain / Oven cleaners | Strong alkali (NaOH, KOH) | Liquefactive necrosis of oral/esophageal tissue โ perforation, strictures. |
๐ Pesticides
Class | Toxic Component | Mechanism of Action | Pathophysiology |
|---|---|---|---|
Organophosphates / Carbamates | Acetylcholinesterase inhibitors | Accumulate ACh at synapses | Muscarinic (SLUD signs), nicotinic (tremors, paralysis), CNS (seizures). |
Pyrethrins / Pyrethroids | Synthetic insecticides | Prolong Naโบ channel opening in neurons | Tremors, hyperexcitability, seizures; cats especially sensitive. |
Metal phosphides (e.g., zinc phosphide) | Produces phosphine gas | Cellular respiration inhibition | Vomiting, pulmonary edema, acidosis. |
Rodenticides (anticoagulant) | Warfarin, brodifacoum | Inhibit vitamin K epoxide reductase | Hemorrhage (delayed). |
๐จ Acute Toxic Causes of Vomiting
Xylitol
Mechanism: Rapid absorption โ potent stimulator of pancreatic ฮฒ-cells โ insulin surge โ hypoglycemia within 30โ60 min.
Pathophysiology: Low blood glucose โ weakness, seizures, collapse.
High doses: Hepatic necrosis due to ATP depletion and oxidative stress.
Toxic dose: As low as 0.05 g/kg (hypoglycemia); >0.5 g/kg (liver injury).
Nicotine
Mechanism: Nicotinic acetylcholine receptor agonist โ initial stimulation โ receptor blockade with high doses.
Pathophysiology: Vomiting (early), tremors, tachycardia โ then bradycardia, respiratory paralysis.
Toxic dose: ~1 mg/kg can cause signs; 9โ12 mg/kg lethal.
๐พ Herbicides
Compound | Mechanism | Pathophysiology / Effects |
|---|---|---|
2,4-D (2,4-dichlorophenoxyacetic acid) | Interferes with oxidative phosphorylation and neuromuscular conduction | Vomiting, ataxia, myotonia, nephrotoxicity; delayed muscle necrosis. |
Glyphosate (Roundupยฎ) | Surfactant toxicity (not glyphosate itself) | GI irritation, hypersalivation, vomiting, diarrhea; rarely systemic toxicity. |
๐ชฒ Blister Beetle (Cantharidin Toxicity)
Toxic Compound
Cantharidin (a potent vesicant produced by Epicauta species beetles).
Source
Beetles contaminate alfalfa hay, especially in horses; dogs can be affected if they ingest contaminated feed or insects.
Mechanism of Action
Cantharidin inhibits serine/threonine phosphatases (PP2A) โ cell junction disruption โ vesicle and blister formation in mucosa.
Pathophysiology
Direct mucosal damage: Ulceration of oral, esophageal, gastric, and urinary mucosa.
Systemic effects:
Hypocalcemia (binding and loss in damaged tissues).
Myocardial necrosis.
Renal tubular damage due to excreted cantharidin.
Clinical signs
Salivation, vomiting (dogs), colic, hematuria, shock.