Following on from last month’s article about toxic foods around Easter time, there are other common human foods that are also toxic to our furry friends.
Onions and garlic are both very common ingredients that are unfortunately toxic to dogs and cats. All of the members of the Allium family of plants (shallots, leeks and chives for example) are dangerous. As these are so commonly found in human foods, anything with these ingredients added can pose a problem, for example, stock powder can contain onion powder. Garlic was once used as a treatment for flea infestations, however this has been proven to not work and conversely can cause major problems in our dogs. The toxic dose of onions is surprisingly small. As little as 0.5% of their body weight in onions can be enough to cause signs of toxicity. They can become ill from eating a large amount at once, or from eating small amounts repeatedly over time.
The main toxic compounds of these plants are organosulphur compounds. They cause inflammation in the gastrointestinal tract, which can range from oral irritation, excessive salivation and nausea to abdominal pain, vomiting and diarrhoea. Luckily this is generally not fatal in dogs but can make them feel quite unwell for a time. The clinical signs can also take anywhere from one to several days to become apparent after they have ingested the toxins. The most toxic effect of these plants is the damage they do to the red blood cells which causes them to rupture. This leads to anaemia, difficulty breathing and potentially death. Other signs that may be seen are yellowing of the gums and conjunctiva, red or brown urine and the breath may smell like onions or garlic. Diagnosis of this toxicity is often based on a history of eating Allium plants, the clinical signs shown and distinctive changes that can be seen in the red blood cells when examined under a microscope.
There is no specific treatment for this Allium spp. toxicity. If your dog has recently eaten onions or garlic, vomiting can be induced and activated charcoal meals can be administered to help reduce the absorption of the toxins. In severely affected animals, hospitalisation, blood transfusions and oxygen therapy may be required.
Macadamia nuts are another common human food that can have serious complications for dogs. Dogs can be affected in multiple ways from eating macadamia nuts. Not only are the nuts themselves toxic, if the whole nut in its shell is swallowed whole, it can cause an obstruction in the intestines that may require surgery to remove. The specific component that is toxic in macadamia nuts is unknown, however dogs can show clinical signs of toxicity if they ingest 2.4g of nuts per kilogram of body weight. The signs can develop within 12 hours of ingestion. The main signs seen are muscle weakness, lethargy, vomiting, muscle trembling, difficulty walking and a high temperature.
Diagnosis of this toxicity is generally dependent on a history of eating the nuts and the clinical signs seen. Sometimes, macadamia nuts may be seen in the vomit or faeces of your dog. There may be a few changes seen on a blood test, but these are generally short lasting and go back to normal levels quite quickly. Luckily, macadamia nut toxicity doesn’t usually cause death, but can involve a short hospital stay depending on their signs. If your dog has eaten macadamia nuts, treatment generally involves inducing vomiting if they have only recently ingested them, followed by feeding activated charcoal to bind the toxins in the intestines. Hospitalisation and stabilisation on intravenous fluids may be required depending on the severity of the signs. If their body temperature is dangerously high, then medications may be given to reduce it.
There are many dogs that like to eat things that we wouldn’t necessarily class as food. A toxicity that we have seen recently is pesticide toxicity. Lawn grubs have been a problem in the last few weeks and many people have been treating their lawns to remove the pests. Unfortunately, there have been reports of a few dogs that have eaten grass that has been treated with these pesticides and have become unwell.
There are many different chemicals that can be used as pesticides and herbicides, and the clinical signs of toxicity can vary greatly. Some general signs include hypersalivation, vomiting, diarrhoea, muscle trembling, high temperatures, seizures or difficulty breathing. Diagnosis of these can be difficult and there are no specific antidotes for most of these chemicals. If you think your dog has been exposed to a toxin, then it is best to contact your nearest veterinary clinic or emergency centre as soon as possible so they can begin to decontaminate your pet and provide them with supportive care depending on the severity of the signs seen.
The best way to avoid a toxicity in your pet is to prevent them from being exposed, which is sometimes easier said than done. We hope that in the coming months that your pets stay safe, healthy and toxin free!
