Common Toxins

Many common toxins are easily accessible by our pets – here’s some of the main one –

Chocolate contains theobromine, a methylxanthine. It also contains caffeine but it is the theobromine that causes the problems. Theobromine is found in greater amounts in the darker types of chocolate, the best source being cooking chocolate.

Mild signs of chocolate toxicity include vomiting, diarrhoea and excitement. The moderate signs include body tremors and cardiac arrhythmias. The severe signs are seizures, which can cause death.

The treatment for chocolate toxicity can be as simple as inducing emesis (vomiting) to remove the chocolate from the dog’s stomach before it is absorbed. If more severe signs are beginning to show, treatment can include admission to hospital for fluid therapy and medications to control tremors and heart arrhythmias. Some cases may even require lavage of the stomach (washing) under anaesthesia to prevent any further absorption of the toxin.

How much chocolate is too much? Any! I am too much of a serious chocoholic myself to ever allow any to be shared with the dog! But sometimes dogs take it into their own paws to gain access to chocolate and we often see problems around Easter or Christmas or when an owner is preparing to cook with chocolate and has everything laid out on the bench. The amount of chocolate that is toxic depends on the amount of theobromine in the chocolate and the size of the dog. Again, darker chocolate is more toxic than milk chocolate. For example, a 5kg dog could be at risk of severe seizures and death with as little as 15grams of dark chocolate, where a 30kg dog could eat as much as 300g of milk chocolate and suffer no problems (other than an unhappy owner!).

If you have any concerns that your dog has eaten some chocolate, please call the clinic with the weight of your dog, the amount and type of chocolate and we will tell you if your dog has eaten a potential toxic amount and what to do about it.

Rat and Mouse baits are very common toxins found in the home, garden or shed. Because they are directed against rodents, they are formulated with grain, which is also very attractive to dogs. Rat baits work by inhibiting Vitamin K, which is used to make several blood clotting factors in the body. When the body stops producing more of these compounds, and the ones in circulation run out, the body will be unable to stop the normal little bleeds that occur spontaneously as a result of normal daily activities.

After ingestion of rat baits the clotting ability of the body will start to be affected within about 24 hours and can be tested by performing a PT (Prothrombin time) test. This is the first of the clotting tests to be affected and is a good early warning of impending bleeding problems. Bleeding is usually noticed 3-7 days after ingestion of the toxin.

Bleeding when it occurs can often be internal (into the chest or abdomen) and so can go unnoticed for some time. Other times, blood may be seen in the faeces, from the nose or mouth or in vomit. Bruising can also sometimes be seen on the skin. The affected dog may appear lethargic, pale in the gums, may start coughing or breathing quickly, may pass blood in the urine or may bleed profusely from a minor wound.

The treatment of rat bait toxicity depends on how long it has been since your dog ate the bait. If ingestion was noticed and it is within 4 hours, usually all that is required is to make the dog vomit and remove the toxin from the stomach. A PT time test will then be advised 48 hours afterwards to ensure all of the toxin was removed from the body.

If it has been longer than 4 hours and enough of the toxin has been absorbed, your dog will need to be given Vitamin K tablets (the antidote) for 2-4 weeks depending on the type of bait eaten. If the dog is already showing signs of bleeding, the treatment is more intensive and vitamin K is required to replace the clotting factors, often blood transfusions to replace the lost blood or plasma transfusions to replace clotting factors. Sometimes oxygen therapy is also required if the dog is having trouble breathing.

Successful treatment depends purely on the time it takes to get to the vet clinic after the bait is ingested. So if you suspect your dog may have had any access to rat bait, please contact your vet immediately. If the vet clinic is closed, go directly to the nearest Emergency Centre to have your dog assessed. This is a very serious toxin that requires prompt treatment.

Snail bait is commonly found in the garden or shed. The most common products are the green baits (Defender) and the blue baits (Baysol). Although containing different compounds, the clinical signs are similar. Dogs who have eaten snail bait will salivate, start vomiting and passing diarrhoea, have uncontrolled muscle tremors and be ataxic and can progress to having seizures which can cause coma and death. Muscle tremors and seizures both cause hyperthermia and this elevated body temperature can cause kidney failure, further gastrointestinal disease, central brain damage and death.

The treatment for snail bait ingestion depends on the severity of clinical signs when the dog is presented to the vet clinic. If the tremors are not too severe, vomiting may be induced to remove the toxin from the stomach and medication may be required to control the tremors. Fluid therapy is also indicated to protect against dehydration, hyperthermia and kidney damage. If seizures are present it is not safe to induce vomiting and so a stomach lavage and enema is performed with the dog anaesthetized.

The other snail bait on the market is the “dog-safe” red product containing Iron EDTA (Multiguard). It is considered dog-safe as it has a bittering agent in it but unfortunately there are many dogs out there for whom this does not act as a deterent and ingest it they will. Multiguard contains iron which can cause toxicity at as little as 2.5g per kg of bait. Iron toxicity causes damage to the inner layers of the gut causing abdominal pain, vomiting and diarrhoea. Often blood is passed in the diarrhoea.

Treatment of Iron toxicity can be extremely expensive. Early detection again requires decontamination of the gut by inducing vomiting or gastric lavage and enema. The iron then needs to be chelated (bound) to prevent any further damage to the gut and this is the expensive bit. Iron chelation requires a drug that is very costly. As well as the chelating agent, the affected dogs also require aggressive fluid therapy, monitoring, antibiotics, pain relief and round the clock treatment. Iron toxicity dogs need to be managed at an emergency centre due to the 24 hour intensive therapy required.

If you must use snail bait on your garden, please fence it off and use snail traps that prevent dogs getting access to the bait but please do not assume these efforts are enough to thwart an inquisitive dog. Please choose the green or blue products over the “dog friendly” Multiguard as this is a misnomer – it is anything but dog friendly and much more serious and expensive to treat. Successful treatment is much easier with the blue and green products. If you suspect your dog has had access to snail bait, get down to your local vet clinic as soon as possible to start treatment.

Grapes and raisins can sometimes cause toxicities in dogs by causing kidney failure. It is not known what compound in grapes causes this damage nor how many are required to be eaten before toxicities occur so it is very difficult to advise on what level of treatment is required. Different dogs appear to be affected by different amounts.

The treatment for grape or raisin ingestion is to cause vomiting to remove the toxin from the stomach and to support the kidneys for 48 hours after ingestion with intravenous fluid therapy. Blood testing is required to monitor how the kidneys are coping.

Lilies are a common flower found in bouquets as they open up into a dramatically beautiful bloom. Unfortunately, the entire Lily plant is toxic to cats and even chewing on a few leaves or petals has the potential to cause acute kidney failure in cats. Inquisitive young cats are most commonly affected as they play with the leaves or flowers.

The clinical signs associated with Lily ingestion are vomiting and lethargy, inappetance and no urine production. Treatment for acute kidney failure includes aggressive fluid therapy and medications to promote the kidney’s ability to produce urine. This is a very serious medical emergency and treatment is not always successful. Education about the severe damage Lilies can do to cats is needed so that they are not given to people who have cats in their home.

Panadol is the most common pain relief medication found in the home and contains the drug Paracetamol. It causes toxicities in both dogs and cats but most commonly and most severely in cats. Dogs can sometimes ingest paracetamol on their own but more commonly owners unwittingly give their pets paracetamol as a painkiller, not realizing the serious damage that it causes. Never give Paracetamol to dogs or cats. There are many safer painkillers specifically developed for pets.

Paracetamol causes different problems in dogs and cats. Cats have a poor ability to metabolise the drug through their liver as they lack certain enzymes. In dogs, paracetamol usually causes acute liver disease and signs seen include vomiting, anorexia, abdominal pain and a high heart and respiratory rate. In cats, the drug usually causes damage to the red bood cells and prevents them being able to carry oxygen as well. Affected cats will have blue or brownish gums, have respiratory distress and can have oedema of their paws and face. They will also vomit and become quite cold.

Treatment of paracetamol toxicity involves removal of the toxin by inducing vomiting and then support of the oxygen carrying system by providing oxygen supplementation and fluid therapy. An antidote is also given if available. Treatment is not always successful so again, if you suspect access to medications containing Paracetamol, please seek immediate veterinary treatment.

Non-steroidal anti-inflammatory drugs (NSAIDs) are a very common and safe pain relief medication often prescribed to dogs and cats. Used at the prescribed dose rates there is little risk, but problems can occur when dogs get access to a large amount of medication all at once or if an overdose is accidentally given. With many veterinary medications made palatable with the addition of beef or liver flavourings, many dogs find these medications quite tempting.

NSAID toxicities can cause gastrointestinal signs, acute kidney failure, liver damage and bleeding disorders. Common clinical signs include vomiting and diarrhoea, inappetance and lethargy. Treatment of dogs with NSAID toxicity includes inducing vomiting to remove the toxin from the stomach, providing fluid therapy to support the kidneys and liver, giving medications to protect the stomach and monitoring with blood tests.

Treatment for NSAID toxicity may take weeks before signs completely resolve and the amount of medication ingested affects the prognosis. If you suspect your dog or cat has had an overdose of anti-inflammatories, please seek veterinary treatment.