Common Household Items that are Toxic to Dogs

Chocolate toxicity

Chocolate contains two ingredients that are toxic to dogs in sufficient quantities – Theobromine and Caffeine. These are both stimulants called xanthines, that humans can break down and excrete much more efficiently compared with dogs.   So thankfully, we can eat large amounts without too many ill effects.  As a rule of thumb – the darker the chocolate the higher the level of xanthines are present.  Cocoa powder and cooking chocolate are therefore the most toxic to dogs, followed by higher percentage chocolate, then milk chocolate.  White chocolate contains minimal xanthines so is relatively nontoxic – however high levels of fat and sugar can cause other complications in your pet such as pancreatitis, so should be avoided.   It is possible to calculate the likelihood of your pet becoming unwell after eating chocolate by using a chocolate toxicity calculator – which can be found online with an internet search.  You will need to know the weight of your dog, the type of chocolate, and the weight of the chocolate that your dog has eaten.  Obviously, your dog may be ok after consuming a larger amount of milk chocolate (250g for a 10kg) but may become critically unwell after only eating a very small amount of cocoa powder (8g for a 10kg dog).  There also seems to be an individual sensitivity with some dogs being more susceptible to the toxic effects of chocolate.

Xanthines directly affect the nervous system and the cardiovascular system therefore some of the clinical signs we can see are:               

Vomiting and diarrhoea

Excessive thirst and urination

Hyperactivity/restlessness

Lack of coordination

Muscle tremors/shaking and seizures

It is important to contact your vet immediately if you suspect your dogs has eaten a toxic amount of chocolate or is showing signs of toxicity.  

Treatment: If your dog is seen by the vet within the first 1-2 hours your vet will induce vomiting to prevent the toxic effects, as there is no specific antidote.  Activated charcoal is then often administered to your dog as this binds to the toxin, and prevents it being absorbed from the intestinal tract.  If your dog is already showing signs of chocolate toxicity, treatment is symptomatic and is aimed at controlling the seizures or tremors, medication to control the heart rhythm, drugs to prevent vomiting, and intravenous fluids to flush out the xanthines from the system.  Xanthines are slowly excreted from your dog’s body so your dogs’ clinical signs may persist for 72 hours. 

Allium species Toxicity

The Allium spp. include onion, garlic, chives and leeks which produce sulphur containing compounds which dogs (and cats) cannot effectively digest.  High levels of these sulphur compounds cause oxidative damage to the red blood cells.  This weakens their membranes and shortens the life of these vital oxygen carrying cells. If enough red blood cells are destroyed your dog will become anaemic and the body is starved of oxygen.  The number of cells damaged is dose dependent, but small amounts fed over a period can lead to problems due to a gradual reduction in red blood cells.  In general, toxicity is consistently noted when dogs eat over 0.5% of their body weight of onion at any one time (50g for a 10kg dog).  Garlic is approximately 3-5 times more potent.  Clinical signs can start in as little as 24 hours after ingestion but usually occur around 3-5 days.

Clinical signs we expect to see are:          

Weakness and lethargy, leading to collapse

Breathing difficulties

Pale gums

Increased heart rate

Not eating

Dark urine

Treatment: If ingestion is recent, then your vet will induce vomiting to prevent symptoms and administer activated charcoal to reduce absorption from the intestinal tract.  However, if your dog is already showing signs of toxicity then he/she may need a lifesaving blood transfusion, oxygen supplementation, intravenous fluids to protect the kidneys and hospitalisation to save their life.

Grape/sultana/raisin Toxicity

It is still unclear which component of grapes and raisins makes them so dangerous to dogs.  However, they contain a toxic compound that can irreversibly damage our dog’s kidneys.  There also seems to be an individual variation between dogs as to how many grapes or raisins they can eat before we see toxic effects.  Some dogs can show signs of kidney damage after only consuming 2 grapes per kg of their body weight. 

Clinical signs usually begin after 72 hours of ingestion and can include:

Vomiting and diarrhoea

Lethargy

Off food

Increased thirst

Abdominal pain

Treatment:  if you know that your dog has eaten grapes/raisins then call the vet immediately.  Your vet will induce vomiting if the ingestion was within the last 1-2 hours and administer activated charcoal to prevent further absorption from the intestinal tract.   If your dog is already showing signs of kidney damage, then they will require lengthy intensive hospitalisation with intravenous fluids and supportive drugs.  If kidney damage is very severe your dog may need ongoing treatment or may not survive. 

Xylitol Toxicity

Xylitol is an artificial sweetener found in many sugar free products such as gum, lollies, drinks, peanut butter, toothpaste and dental floss.  In dogs, unlike humans, xylitol stimulates a dose dependent release of insulin from the pancreas.  This can result in a rapid lowering of our dog’s blood glucose which is called hypoglycaemia.  This often happens within an hour of ingestion but can be delayed with slower absorption from some gum products.  With consumption of larger doses of xylitol, the liver can also be damaged. 

Clinical signs we can see associated with ‘hypoglycaemia’ are:

Weakness

Vomiting

Lack of coordination

Tremors, seizures, coma.

Signs associated with liver disease can be:

Vomiting

Off food

Yellowing of the eyes/gums/skin

Severe lethargy

Treatment:  If your dog has only just eaten the product and has no clinical signs, your vet may induce vomiting.  Activated charcoal does not bind to xylitol so is usually not given.  Once signs of hypoglycaemia are present your dog will need prompt treatment with intravenous glucose to correct the blood sugar for up to 24 hours.  Your vet will also need to monitor for signs of liver disease which will be treated accordingly.  With mild liver damage your dog may make a full recovery, however if your dog has eaten a large amount of xylitol and liver damage is severe, it may prove fatal.

Macadamia Nut toxicity

We still do not understand why macadamia nuts are toxic to dogs.  Some dogs have shown toxic effects after only eating 1 nut per kg of body weight, whilst others can eat many more with no ill effects.

Clinical signs are usually seen within 12 hours of ingestion and include:

Vomiting

Weakness and a staggering gait

Tremors

Fever

Treatment:  If your dog has eaten a potentially toxic amount of macadamia nuts, then your vet may induce vomiting followed by the administration of activated charcoal to prevent further absorption from the intestinal tract.  If your dog is showing clinical signs, then treatment is symptomatic involving intravenous fluids to help excretion, drugs to stop vomiting, drugs to help with the fever and drugs to stop the tremor.  Most dogs recover without further complications over 48 hours.