ivermectin

1. Ivermectin Worm medication used orally and parenterally in most species (Heartguard, Ivomec, Eqvalen, Zimecterin) Cumulative toxicant Young animals more susceptible Often a problem in dogs given horse paste

2. Ivermectin Dogs-6ug/kg =heartworm preventive dose; 2.5 mg/kg PO =mydriasis, 5mg/kg PO= muscle tremors, 40 mg/kg PO= death Collies, Aust. Shepherd, Shelties, Border Collies- 0.1 -0.2 mg/kg PO or SC causes toxicity and death Cats-0.5mg/kg=mydriasis and tremors Equine-2mg/kg=ataxia and blindness Cattle and Sheep-4mg/kg=ataxia/death

3. Ivermectin Mechanism of action is to increase GABA release, affinity of GABA receptor and direct GABA agonist Onset time is hours to 1 day, affects CNS Clinical signs-hypersalivation (dogs), tremors, bradycardia, convulsions, coma, mydriasis, blindness, ataxia Can see anaphylactic reactions in dogs No visible lesions

4. Ivermectin Diagnosis History of administration Brain ivermectin concentration >100ppb Treatment Short acting barbiturate for convulsions (no benzos) IV physostigmine (0.04mg/kg) BID in comatose animals Flumanezil and moxidectin-expt. Benzo antagonists Epinephrine, fluids for anaphylaxis

5. Household Cleaners Product warning label indicates level of toxicity No label = LD50 > 5 g/kg Caution = 0.5 – 5 g/kg Warning = 50 – 500 mg/kg Danger: Poison = <50 mg/kg

6. Soaps, Shampoos, Detergents Most have low toxicity Usually cause only vomiting and diarrhea Cationic surfactants are found in contact lens solutions, fabric softeners, swimming pool algicides; can cause neuromuscular and ganglionic blockade as well as GI ulcerations, acidosis and shock Anionic surfactants are in many cleaning products like shampoos have the potential to cause hemolysis

7. Disinfectant Cleaners Products like Lysol contain phenolic compounds mixed with detergents Pine oil based compounds like Pine Sol These products are especially toxic to cats due to metabolism by glucuronidation; can cause liver injury, jaundice, and renal damage in conjunction with GI problems Phenolics also found in creosote and tar paper; watch out for pigs

8. Alkaline Compounds Ammonia, Oven Cleaner, Most Drain Openers All have pH of >12 which can cause burns (ulcerations) Ulcers can be very severe, especially with granular drain openers Ingestions causes GI ulcerations, vomiting, salivation, dysphagia (esophageal stricture), dyspnea Bleach and scouring powders with bleach usually not high enough pH to cause ulceration; can be a problem if mixed with ammonia = chloramine gas

9. Acidic Compounds Toilet bowl cleaners, concrete cleaner, Lime-A-Way, some drain openers Can cause severe burns, but usually not as deep as alkali Signs and treatment similar to alkaline products

10. Treating Household Cleaner Ingestions If a potentially toxic amount of a non-corrosive compound ingested, emesis should be induced; no activated charcoal unless systemic effects are expected For corrosive compounds 1) dilute with milk or water, 2) determine exactly how much of what material was ingested

11. Treating Toxic Corrosive Ingestions If there is pain, dysphagia, excessive drooling, or ulceration and the exposure was potentially toxic: Establish airway and get esophagoscopy If esophagus can’t be examined quickly, start corticosteroids If examination indicates burns, give corticosteroids Symptomatic and supportive care

14. Petroleum Products Gasoline, mineral spirits, kerosene, lighter fluid, nail polish remover, solvents, motor oil, furniture polish Biggest worry is aspiration causing hydrocarbon pneumonia Pneumonia risk related to viscosity; less viscous = more toxic

15. Systemic Toxicity of Hydrocarbons Most hydrocarbons are CNS depressants Some volatile hydrocarbons sensitize the heart to catecholamines and can cause sudden death due to cardiac arrest Many hydrocarbons cause dermal irritation and hair loss

16. Signs of Hydrocarbon Toxicity Depression, lethargy, ataxia, seizures, coma Dyspnea, coughing, wheezing, X-ray changes in lungs with pneumonia Spontaneous vomiting and aspiration often occurs with more volatile compounds

17. Treating Hydrocarbon Ingestions Wash for dermal exposures Do not try to increase viscosity by adding heavier compound Do not induce emesis unless a large, life threatening ingestion (>1 ml/kg) Monitor for pneumonia; treat with antibiotics if present

18. Oak (Acorn) Poisoning Red Oak are most toxic due to high tannins, Live Oak is questionable problems are seasonal, usually in fall after a storm or during summer droughts primarily affects cattle; calves are more susceptible Toxic priniciple is thought to tannins or their metabolites Animals must consume large amounts of acorns or buds to be toxic

19. Oak poisoning Cases have relatively low morbidity with moderate mortality (35-80%) Animals usually ingested acorns for 1 week prior to signs Symptoms are primarily renal and GI-anorexia, depression, weakness and possible nasal discharge; progresses to rumen atony, black tarry diarrhea, ventral edema, dehydration. terminal animals are often recumbent near water

20. Cyanogenetic Plants Wild and choke cherry, Sudan and Johnson grass, Flax, Sugar beet tops, Arrow grass contain glycosides with cyanide groups

21. Thiaminases Horsetails and Bracken Ferns Thiaminases destroy thiamine causing neurological problems; causes aplastic anemia in ruminants Primarily affects horses and ruminants Usually occurs if other forage is inadequate

23. Calcium Oxalate plants Members of Araceae family contain calcium oxalates; Dieffenbachia (Dumb Cane), Philodendron, Elephant ear, Calla lily, Arum lily, Caladium All parts of plant are toxic; stalk more toxic than leaves Usually occurs in cats, dogs, birds, and lizards Rarely life-threatening

24. Calcium Oxalate plants Preformed calcium oxalate crystals embed in all parts of GI tract; also contain proteolytic enzymes that cause histamine release Onset time is immediate; primarily affects GI system Clinical signs include head shaking, salivation, dyspnea, vomiting, diarrhea, loss of voice

25. Calcium Oxalate plants Diagnosis is by history of exposure and compatible clinical signs Treatment Rinse mouth with water Anithistamines for dyspnea Demulcents (Kao-pectate; no Pepto in cats) Fluids for severe vomiting and diarrhea

26. Precatory Bean; Rosary Pea Grows in Carribean Commonly sold as rosary “beads” Extremely toxic, 1 pea can kill a child or dog Severe enteritis leads to shock

27. Castor Bean Common plant in S. Florida Mole plant Seeds are extremely toxic due to ricin

28. Oleander Contains cardiac glycosides (much like digitalis) Highly toxic

29. Cassia Coffeeweed, sicklepod Causes muscle degeneration

30. Crotalaria Rattlebox Causes liver injury

31. Cycas and Zamia Sago Palms, Coontie Plants Seeds are especially toxic Causes liver injury

32. Sesbania Seeds are most toxic part Produce severe hemorrhagic or necrotic enteritis

33. Cestrum Day and night blooming jessamine Contains Vitamin D Kidney damage

34. Lantana Causes photosensitization secondary to liver injury