Our pets are an integral part of the family and we want to keep them safe and healthy at all times. If you have a pet you need to be aware that something as simple as feeding them the wrong food could lead to serious problems. 

Familiarising yourself with common pet poisons in your animal is advisable to prevent potential toxicities. If poisoning should occur, it is also beneficial to recognise that the substance is toxic in order that prompt veterinary treatment can be sought.

If you suspect that your pet has ingested something dangerous, it is essential you visit a vet straight away. Better to be safe than sorry when it comes to your beloved pet.

Understanding toxic foods for pets 

Certain human foods can cause severe health problems if ingested by a pet. In some extreme circumstances, the wrong food can be life-threatening. Certain foods can be more toxic to one species than another, so it’s important to familiarise yourself with what is safe.

Common Toxins in Cats: 

There are several foods toxic to cats that can cause a range of health problems, some even life-threatening if consumed. 

Onions, garlic, chives, and leeks

Onions are part of the Amaryllidaceae family. This genus Allium also includes garlic, chives, and leeks. 

Allium species contain sulfoxides (sulfur-containing compounds), which are readily absorbed by the gastrointestinal tract and when absorbed into the bloodstream disrupt red blood cell membranes, resulting in red blood cell rupture which can result in anemia. As little as 5g/kg (or 20g in the average-sized 4kg cat) is enough to cause toxicity.

Breakdown products from red blood cell rupture may also result in kidney damage or failure.

Cats remain more sensitive to this form of poisoning than dogs (although this remains a toxic risk in dogs). 

Signs to look for: Weakness, lethargy, pale gums, collapsing, vomiting.

Grapes, currents, raisins and sultanas

While the exact mechanism of toxicity and amount required to produce this remains unknown this food group is known to cause kidney damage and, in some cases, can result in kidney failure.

Signs to look for: lethargy, vomiting, diarrhoea inappetence, seizures.

Feeding exclusively fish, particularly if cooked or smoked (eg. salmon, tuna)

Feeding a diet comprised solely of fish is not advised in carnivores as this can result in Thiamine (Vitamin B1) deficiency. Thiamine is essential to carbohydrate, amino acid, and fatty acid synthesis and metabolism. Thiamine can be destroyed by heat, sulphur preservatives, and in diets high in thiaminase (an enzyme that breaks down Thiamine) such as raw fish. Thiamine deficiency results in progressive neurological signs with the brain being particularly vulnerable as it requires Thiamine for many critical cellular processes.

Signs to look for: Early onset vomiting and inappetence followed by possible seizuring, impaired vision, weak or wobbliness on legs, head tilt.

Dairy Products

Many dogs and cats are lactose intolerant, which means that dairy products consumed can cause gastrointestinal upset. Milk is only required in the nursing stages of puppies and kittens under 6 weeks of age. Therefore, if milk is desired as a dietary addition in an adult animal a pet milk is advised (eg. Whiskas Milk Plus Lactose Free milk for Kittens & adult cats).

Dog food

While dog food might not be toxic, it can lead to nutritional deficiencies and imbalances if consumed by cats. Generally dog food contains insufficient levels of the following nutrients required in cats:

Protein: Cats are strict carnivores requiring a higher protein diet than dogs (which are omnivores eating both meat and plant-based material). Most commercial dog foods are too low in protein to meet a cat’s protein requirement. Likewise feeding a cat a “vegetarian” or “vegan” diet is dangerous and completely inappropriate for their metabolic needs and will result in severe illness and death if continued to be fed.

Signs to look for: inappetence, weakness, lethargy, seizures, coma

Remember a cat does not have a choice in what it eats and must consume meat!  Pet owners’ beliefs should not be forced on our pets at the cost of their health and well-being.

Taurine: Cats, like people, cannot make their own taurine naturally in their bodies. Cats must therefore obtain taurine from their diet. Most dog foods do not have a high enough taurine content for cats. Signs of taurine deficiency include digestive upset, loss of vision, and heart problems. 

Niacin: Cats are also unable to make their own niacin vitamin within their body.  Animal tissue is high in niacin, so a high-protein diet is also required in this respect.

Vitamin A: Again, cats cannot produce their own Vitamin A and must obtain it from their diet. Dog food is too low in this vitamin for cats. Signs of Vitamin A deficiency include weak muscles, dull hair coat and night blindness. 

Arachidonic acid: This fatty acid is unable to be produced naturally in cats whereas dogs create arachidonic acid themselves. Dog food, therefore, contains lower amounts than cat food. Signs of deficiency can include liver and kidney disease and various skin diseases.

Acetaminophen (Paracetamol)

If you feel your cat is in pain it is often best to consult a veterinarian before administering home medications.

Acetaminophen (Paracetamol) is highly toxic to cats due to their inability to metabolise this drug due to their body lacking the required enzymes. In order for cats to metabolise Acetaminophen they must use another metabolism pathway which results in toxic metabolites (breakdown products) being produced. 

Toxicity is characterised by two processes:

1. The inability of red blood cells to carry oxygen around the body results in low oxygen and collapse with blue/dark gums and struggling to breathe. This may also result in kidney damage
2. Liver toxicity with liver tissue damage and failure

In cats, toxicity can occur with as little as 40mg of Paracetamol ingested in an average 4kg cat! Compare this to dogs where toxicity can occur in the same size 4kg dog but with a minimum toxic ingestion of 400mg. This illustrates the cat’s sensitivity to this toxin and marked inability to process it.

Signs to look for:  Dark brown/muddy gum colour or blue gum colour, increased heart rate and respiratory rate, weakness, collapsing, depression, weakness, vomiting, hypothermia, yellow gums or skin (icterus), facial or paw oedema (fluid swelling)

Common Toxins in Dogs: 

As dogs love wandering around the home trying to find food, it’s important to be mindful of what food is in reach. There are many toxic foods for dogs that you may have around your home and yard without even realising. 

Macadamia nuts

The process involved in producing toxicity from macadamia nuts remains unknown however even consuming small amounts of these can lead to very serious illness. It should also be kept in mind that macadamia nuts can be coated in other products that are toxic to pets such as chocolate, xylitol sweetener, and grape products. 

Signs to look for: weakness, staggering, vomiting, tremors, hyperthermia.

Chocolate

While chocolate is a toxic food for dogs and cats, dogs are more likely to be affected as cats are usually too discriminating to eat chocolate in large quantities.

The severity of chocolate toxicity depends on the type of chocolate ingested, the amount and the size of the pet.

Chocolate contains methylxanthines; namely theobromine and caffeine 

Darker and more bitter chocolate (eg. higher percentage cocoa and cooking chocolate) contains more theobromine and caffeine and hence tends to be more toxic than milk and white chocolate but again this will depend on the quantity consumed.

It is also worth remembering that some chocolate products contain other toxins such as coffee beans, macadamia nuts, raisins and xylitol.

Signs to look for: hyperactivity, increased heart and respiratory rate, vomiting, diarrhoea, increased thirst, hyperthermia, tremors, and seizures.

Xylitol 

Xylitol is a sweetener used as a sugar substitute in many pharmaceuticals, oral care products and as a food additive. It is found naturally in fruits such as berries and plums as well as corn, oats, mushrooms, lettuce and many trees. Commercially used Xylitol is extracted from corn fibre or birch trees and has gained popularity as a sugar substitute due to its low glycaemic index and dental plaque fighting properties.

Products containing xylitol include: 

• Oral care products (eg. Mouthwash, toothpaste, sugar-free gum, breath mints)

• Foodstuffs (eg. Candy, baked goods, peanut butter, pudding snacks)

• Supplements and over-the-counter medications (eg. cough syrup, chewable or gummy vitamins, nasal sprays, skin care products, laxatives, digestive aids, allergy medications, mouth lozenges, sleep supplements)

• Pharmaceutical medications especially those formulated as quick-dissolve tablets or liquids.

Xylitol is extremely toxic to dogs. The Xylitol is absorbed into the bloodstream which causes a rapid release of insulin from the pancreas which results in a marked drop in blood sugar (hypoglycaemia) which can be life-threatening. Xylitol is also known to cause seizures as well as liver failure however this process is poorly understood.

Signs to look for: vomiting, lethargy, weakness, wobbliness, tremors, seizures, coma.

Are plants dangerous to pets? 

Certain plants contain toxins that can cause a range of health problems if ingested ranging from mild to severe.

Familiarise yourself with what houseplants are toxic to pets so you know what plants to keep away from your home. You should also make sure there are no toxic plants growing in your garden that could be a problem for your pets. 

Lilies

Lilies are one of the most common toxic plants for cats. Ingestion of any part of this plant (flower, stamen, leaves or stems) can cause kidney failure. 

All members of the genera Lilium and Hemerocallis should be considered nephrotoxic to cats and potentially dogs. This includes the Easter lily (Lilium longiflorum), tiger lily (Lilium species) and daylily (Hemerocallis species), among many others.

Signs to look for: Initial depression, vomiting, inappetence. If allowed to progress lily toxicity can result in kidney damage and failure.

Sago palm

Part of the Cycad/Cycas, Microzamia or Zamia genus these palms are also known as Coontie palms, Cardboard palms, Japanese cycad, Cycads, or Zymias, sago palms and are readily available for purchase in stores ranging from small nurseries to the garden sections of large home improvement stores. All parts of the sago palm plant are toxic.

Signs to look for: Gastrointestinal irritation with depression, drooling, vomiting and diarrhoea. Neurological signs including weakness, wobbliness, tremors, and seizures. If left untreated advanced signs may include liver damage with yellow skin or eyes (icterus), increased thirst and urination and dark urine. With liver disease decreased blood clotting may also occur resulting in bleeding both internally and externally.

Aloe vera 

While aloe vera can be beneficial to humans, it can cause vomiting, diarrhoea, and digestive upset in dogs and cats if ingested.

Azalea and Rhododendron

Azaleas and Rhododendrons are classified as part of the same family with all parts of the plant including the flower, leaves and shrub being toxic.
These plants contain a toxin called grayanotoxin, which disrupts the electrical pathway in muscle tissue including heart muscle. 

Signs to look for: Gastrointestinal signs: inappetence, drooling, vomiting diarrhoea, abdominal pain. Cardiovascular signs: abnormal heart rate, low blood pressure, Neurology signs: depression, muscle tremours, blindness, seizures, coma.  

It is important to note that these lists are by no means exhaustive and there may be other toxins that may cause potential health concerns in your pet.

What to do if your pet is unwell?

Contact your veterinarian immediately for guidance on the best course of action. Observe any symptoms and follow your vet’s recommendations for treatment, which may include medication, rest, or changes to their diet or environment. Prompt intervention can be crucial for a successful recovery, so don’t hesitate to seek help if you have concerns about your pet’s health. 

A vet you can trust at Clyde Veterinary Hospital 

We have a team of trusted veterinarians who are leaders in pet care. 

We value preventative care to keep your pet healthy and endeavour to identify any concerns before they become a bigger issue. 

If you have any questions or would like to book an appointment please give us a call at (03) 9069 4088 or email us at info@clydevet.com.au