As I watched Wilson, my new 11 week old French Bulldog puppy, on one of his first outdoor romps I couldn’t help notice how innately curious and innocent dogs can be when just starting to explore the world outside.
Everything was new and amazing! Look at that cool leaf, and listen to that bird call. And what is THAT…a squirrel? He was so into everything around him. All that he could see, hear, touch, and taste became fascinating to his mind and his senses.
I loved watching him enjoy it all, but as a seasoned vet,I also was on the alert for anything that could be harmful nearby to the naïve little guy. He was my new pal, and it was my job to look out for him while he learned about life in Seattle.
It is after all, the responsibility of all dog owners take on such a guardian type role for the benefit of their canine companions. Regardless of the pet’s age, experience level, and the environment they find themselves in, dogs will be dogs. And they sometimes get themselves into heaps of trouble!
Since they also have a knack for eluding our close observation and supervision, even if just for a moment, I thought it would be good to think about what to watch for if, despite your best efforts, your dog may have eaten or contacted something toxic.
Often the sooner we can spot a toxicity problem, the more successful the outcome will be from prompt first aid and/or the necessary medical attention.
Here are some commonly encountered environmental toxins and the potential signs or symptoms that should alert a dog owner to take action. Some come from outside the home, while others are surprisingly accessible within the apparent safety of the dog’s indoor environment.
1. Rat or rodent bait ingestion: There are 3 types of rodent poisons used commonly now in North America, and each has a different toxic effect with varying post-poison symptoms.
- Anticoagulants (most common) act within days of ingestion to inhibit blood clotting by interfering with normal Vitamin K activity. Bleeding or bruising, pale gums and mucous membrane color, weakness/exercise intolerance, lameness, and swollen joints are all possible clinical signs. These signs may be delayed by days after actual ingestion and can last weeks after exposure. Early action in first 24hrs after exposure can be very effective.
- Bromethalin is a potent nerve toxin and as such can lead to acute central nervous system symptoms including muscle tremors, seizures, agitation, forelimb stiffness, incoordination, mental depression, loss of vocalization, and paralysis. Since there is no antidote, rapid and early treatment aimed at reducing further intestinal absorption is essential to survival!
- Vitamin D containing poisons act by overdosing this important calcium and phosphorus cofactor and can result in toxic levels of these minerals in the blood leading to acute kidney failure, heart function issues and even damage to other body organs. Clinical signs usually have a delay in onset of 18 - 36 hours post ingestion. The most common signs seen includevomiting, diarrhea, reduced appetite, depression, thirst increase, and body collapse.
2. Slug bait ingestion: Most older baits use metaldehyde as the active poison and oral ingestion leads to nerve and muscular abnormalities that develop within hours of ingestion.
Signs of this toxicity includeincoordination, severe muscle spasms/twitching, abnormal posturing or movements, and even convulsions. There is no direct antidote, but rapid post-exposure medical care can help relieve and lessen the symptoms considerably. The newer “pet-safe” snail baits frequently contain large amounts of iron mineral, and are only toxic after ingestion of very large quantities. The mechanism of toxicity is very different and more delayed (days after exposure), but preventing consumption of large amounts can keep dogs safe.
3. Antifreeze ingestion: Ethylene glycol is the most dangerous form of antifreeze. Most commercial antifreeze products contain between 95-97% ethylene glycol. A minimal dose of ½ teaspoon per pound of body weight is enough to possibly poison a dog. Acute vomiting is seen within the first few hours after ingestion and then, within 1-6 hours, signs ofdepression, incoordination, weakness, panting, increased thirst and urination occur. By 18-36 hours, acute often lethal kidney failure occurs. Propylene glycol is the main ingredient in "safer" forms of car engine coolant and is approximately 3 times less toxic in dogs than ethylene glycol.
4. Xylitol artificial sweetener ingestion: This common food ingredient is a naturally occurring sugar substitute found in many sugar-free gums, candies, etc. Even small ingested amounts in dogs can result in rapid, life-threatening low blood sugar levels (hypoglycemia), while larger doses result in liver damage and failure. Signs of poisoning typically occur rapidly within 30-60 minutes of ingestion including weakness/lethargy, incoordination, collapse, even convulsions.
5. NSAID drug toxicity/overdose (human or canine drugs): These common often OTC human drugs as NSAIDs (e.g. Advil®, Aleve® and Motrin) can cause serious harm to dogs when ingested, causing stomach and intestinal ulcers as well as potential kidney failure. Damaging effects can be variable with many factors such as size of dog, quantity ingested, actual active ingredient and individual sensitivity to NSAIDs dictating the degree of harm that results. Signs occur typically within hours to days and include appetite loss, vomiting, diarrhea with or without blood, and possibly increased thirst. Even an overdose of a prescription dog NSAID can have similar toxicity.
6. Antidepressant drug toxicity/overdose: Antidepressants (e.g. Prozac, Paxil, etc.) when ingested by dogs can cause vomiting and, in more serious instances, “serotonin syndrome” -- a dangerous condition that raises temperature, heart rate, and blood pressure, and may cause seizures.
7. Cocoa/Coffee stimulant toxicity: This one is a classic and quite well known. Though not harmful to people, in dogs chocolate products contain enough substances called “methylxanthines” that can cause rapid heart and irregular heartbeats, vomiting and diarrhea in small doses, but severe signs and even death if ingested in larger quantities. Darker chocolate contains more of these dangerous substances than do white or milk chocolate.
The amount of chocolate that could trigger serious symptoms depends on the type of chocolate and the dog’s size. For smaller breeds, just half an ounce of baking chocolate can be fatal, while a larger dog might survive eating 4 ounces to 8 ounces.
Coffee and caffeine have similarly dangerous chemicals with poisoned dogs experiencing similarhyperactive and overly stimulated signs as with cocoa/chocolate products toxicity.
8. Macadamia nut ingestion: This popular ingredient in human snacks (or eaten as a plain nut) isn’t well known for its toxic effects. However, after ingestion dogs may suffer from a series of symptoms, including weakness, depression, joint pain, overheating, and vomiting. The toxin hasn’t been identified and there is no antidote, but signs generally subside in 24-48 hrs.
9. Raisins and Grapes: Experts in research aren’t sure why, but these fruits can induce kidney failure in dogs. The amount of grapes or raisins that may cause such renal failure is not exactly known, so any amount could potentially be dangerous. Even a small number may cause problems in some dogs. Signs like vomiting, reduced appetite, low urine production, and a possible painful belly would typically appear within 24hrs of ingestion.
10. Marijuana ingestion: This recreational drug’s use and thereby inadvertent dog ingestion episodes are becoming more common. Most likely signs of toxicity are mental depression, incoordination, vomiting, tremors, dilated pupils, and “stealing Doritos”. Thankfully, prognosis is good and mostly supportive care and symptomatic. Effects can last between 24-72hours.
This list is a sampling of the more common potential hazardous items that unlucky dogs and their owners may encounter while living together. Hopefully, avoiding exposure and eliminating unsupervised dog activities in and around our homes and communities can prevent such toxic episodes. However, if exposure does occur, knowing what observations to make and how to proceed if poisoning is suspected can likely save much suffering and even our pet’s lives.
If nothing else, remember that dogs will be dogs, and they can never be trusted to eat only the right things!
Dr. Mark Donovan earned his degree with Honors from the University of Florida (Go Gators!). His veterinary interests include soft-tissue surgery, endocrinology, epidemiology, and zoonotic diseases. He has one pet – a French bulldog named Wilson.
Dr. Donovan enjoys spending time with his wife and two daughters, hiking and backpacking, snowboarding, playing tennis, gardening, going to Mariners games, and reading.
Seattle Veterinary Associates was founded in 1971 by Dr. Sanford Olson, Dr. Donald Canfield, and Dr. Stephen Jones. In 1971, the original practice opened its doors at the current location of Queen Anne Animal Clinic. Coupled with our considerate expansion and the advancement of our medical capabilities at all our hospitals, we are proud to be providing the highest quality veterinary care to pets and their families. SVA is comprised of four locations: Queen Anne Animal Clinic, Green Lake Animal Hospital, Ravenna Animal Hospital, and Northwest Veterinary Hospital.
