Dr Liesel van der Merwe is a small animal medicine specialist. Send her your questions: This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Dr Liesel van der Merwe

Veterinarians see a lot of avoidable poisonings. Some are transient, with vomiting and diarrhoea and vague neurological signs, and others cause irreparable renal or liver damage.

If you think your animal has been exposed to toxins, then early treatment drugs to make them vomit and dosing with activated charcoal to limit toxin absorption are very valuable. Delaying treatment until you are sure a substance was ingested because the animal starts showing symptoms may worsen the outcome.

Plants
Cycads are becoming increasingly popular as landscaping plants. They are, however, extremely toxic to dogs. Cycads have several toxins, the predominant of which is cycasin, found in all parts of the plant with the highest concentrations in the seeds and roots.
Poisoning is characterised by vomiting, diarrhoea and lethargy within 24 hrs of ingestion. Chewed leaf and seeds may be seen in the vomitus. Some dogs develop bloody diarrhoea. Liver damage becomes apparent two to three days after exposure with a recurrence of vomiting, lethargy and inappetance. The liver damage is often fatal.
Yesterday today and tomorrow bush (Brunfelsia spp) may cause vomiting and diarrhoea, hyperaesthesia, tremors and seizures. The effects are temporary.
Morning Glory (Ipomoea) causes agitation, tachycardia, unco-ordination and  hallucination.
Castor bean bush (Ricinus communis) causes vomiting, haemorrhagic enteritis, tremor, seizure, coma or death. Kalanchoe spp causes vomiting and diarrhoea, lethargy and possibly cardiac arrhythmias.
Chincherinchee can cause severe gastroenteritis if bulbs are eaten. Oleander (Nerium oleander) causes heart arrhythmias. Lilly (Easter lily, tiger lily ) – even minimal exposure to cats causes acute kidney failure. All parts, including pollen, are toxic but flowers contain the highest amount. It causes only mild gastrointestinal upset in dogs.
Elephant ear, Arum lily, poinsettia – oxalate crystals in the leaves and stems cause transient intense oral irritation with hyper-salivation and local swelling.

Products
Panado (acetaminophen) – Cats are very sensitive to Panado and develop a severe  haemolytic anaemia and lack of oxygen to the tissues. Dogs are more resistant, but very high doses can cause liver failure.
Anti-inflammatories – Dogs need to take in 5-10 times the recommended dose of animal registered medication before clinical signs become apparent. Human medications are much stronger and accidental ingestion of pills can cause gastric ulcers, kidney failure and liver damage. 
Onions and garlic (Alium spp) – Ingestion causes a haemolytic anaemia (pale gums and red urine) in dogs and cats. Cats are much more susceptible .
Ratex/ Coumadin – There is no safe rat poison. Dead rats are not poisonous, as they ate the poison about three days before, but live rats with fresh bait in their GI tract could poison dogs if they are caught and eaten. Rat poisons cause internal bleeding.
Chocolate – The darker the chocolate, the more toxic. Animals with heart disease or predisposed to seizures are more sensitive. Clinical signs depend on the amount eaten: agitation, nervousness, rapid heart rate and breathing, hyperthermia, arrhythmias, tremors and seizures.
Macadamia nuts – Ingestion causes transient depression, hyperthermia, mild tremor, weakness, especially in hind limbs, muscular rigidity and ataxia.
Ethylene glycol  (antifreeze) – It causes severe, acute kidney failure if ingested. 
Grapes and raisins – Some individual dogs are susceptible and develop acute renal failure, vomiting and diarrhoea within 12 to 24 hours of ingestion.
Mothballs (naphthalene balls) – Acute onset vomiting and diarrhoea. Haemolytic anaemia (red urine and pale gums) may occur 12 to 48 hours after ingestion.
Potpourri (liquid essential oils) – If the oils are licked they can cause oral and oesophageal ulceration, lethargy, drooling, vomiting, anorexia and tongue protrusion. The oils are also volatile and may cause respiratory distress if breathed in.
Xylitol (a sweetener) – It can cause vomiting and diarrhoea. Hypoglycaemia may develop due to increased insulin levels. It may also be hepatotoxic in predisposed animals.