Tag Archives: poisoning

Why chocolate is really, really bad for dogs

The only good chocolate for dogs is a chocolate fur, like is majestic lab is rocking. Credit: Pixabay.

Unlike cats, which lack the ability to taste sweetness, dogs find chocolate just as appealing as humans. But while the dark treat can be a euphoric delight for us, it can be poisonous to canines.

That’s not to say that all dogs get poisoned by chocolate or that a candy bar is enough to necessarily kill your pet canine. The dose makes the poison. The weight of the dog also matters, so large canines should be able to handle a small amount of chocolate whereas smaller breeds might run into serious trouble.

Although you shouldn’t panic if your dog accidentally ingests chocolate, candy and other chocolate sweets should never be offered to dogs. Generally, you should treat chocolate as toxic to dogs and should make an effort to keep it away from them.

Why chocolate can be dangerous to dogs

Among the many chemical compounds found in dark chocolate and cocoa is theobromine. Formerly known as xantheose, theobromine is a bitter alkaloid compound that acts as a mild stimulant for the human body.

The consumption of theobromine is generally associated with positive effects, such as reduced blood pressure, improved focus and concentration, and enhanced mood. That’s in humans. In dogs, theobromine, as well as caffeine, raise the heart rate and can overstimulate the nervous system.

Because dogs can’t break down, or metabolize, theobromine as well as humans can, the compound is toxic to dogs, over a certain threshold, depending on their body weight.

Mild symptoms of chocolate toxicity occur when a canine consumes 20 mg of theobromine per kilogram per body weight. Cardiac symptoms occur at around 40 to 50 mg/kg and dangerous seizures occur at doses greater than 60 mg/kg.

This explains why a candy bar may cause a chihuahua (average weight 2 kg) to run in circles while Great Dane (average weight 70 kg) might feel just fine.

Darker, purer varieties of chocolate tend to be the most dangerous because they contain the highest concentration of theobromine. According to the USDA nutrient database, various chocolate/cocoa products contain the following amounts of theobromine per 100 grams;

  • Unsweetened cocoa powder: 2634 mg;
  • Baking chocolate (unsweetened): 1297 mg;
  • Dark chocolate (70% cocoa): 802 mg;
  • Mars Twix (twin bar): 39.9 mg;
  • White chocolate: 0 mg;

As a rule of thumb, chocolate poisoning in dogs generally occurs after the ingestion of 3.5g of dark chocolate for every 1kg they weigh, or 14g of milk chocolate for every kilogram.

Signs that your dog may be suffering from chocolate poisoning

Chocolate poisoning mainly affects the heart, central nervous system, and kidneys. The symptoms of theobromine toxicity usually appear within 6 to 12 hours after your dog eats too much chocolate and may last up to 72 hours. These include:

  • vomiting,
  • diarrhea,
  • restlessness,
  • increased urination,
  • tremors,
  • elevated or abnormal heart rate,
  • seizures,
  • and in extreme cases collapse and death.

Can chocolate kill dogs?

In short, yes. However, fatalities in dogs due to chocolate poisoning are very rare. According to the Veterinary Poisons Information Service from the U.S., out of 1,000 dog chocolate toxicity cases recorded in its database, only five dogs died. 

What do if your dog eats chocolate

If you caught your dog eating chocolate or you suspect this may have happened, it is best to call your veterinarian and ask for advice on how to proceed going forward. Based on your dog’s size and the amount and kind of chocolate ingested, the veterinarian may recommend monitoring your dog for any symptoms of poisoning or ask that you immediately come to the clinic.

If there are good reasons to believe potentially dangerous chocolate poisoning may be imminent, and as long as your pet consumed the chocolate less than two hours ago, the veterinarian may induce vomiting.

Sometimes, the dog may be given doses of activated charcoal, which helps to flush toxins out of the body before they are absorbed into the bloodstream.

In very extreme cases of poisoning, the veterinarian might administer medications and/or intravenous fluids to provide additional treatment.

Keep chocolate away from dogs

There’s no reason to believe chocolate isn’t as tasty to dogs as it is to humans. Unfortunately, many dog owners are ignorant to the fact that chocolate can poison their pets and intentionally offer chocolate snacks as a treat.

Usually, this isn’t a problem for very large breeds when they ingest small amounts of chocolate, but smaller dogs can suffer greatly and even die in extreme cases due to theobromine poisoning.

If you are aware that chocolate can poison your pet, you have no excuse to keep sweets accessible. It is advisable to keep any chocolate items on a high shelf, preferably in a closed-door pantry. Guests and children should be kindly reminded that chocolate is bad for dogs and that they shouldn’t offer chocolate treats regardless of how much the pet begs for them.

Most chocolate poisoning in dogs occurs around major holidays such as Christmas, Easter, or Valentine’s Day, so these are times when you should be extra careful. 

Novichok: how are victims surviving poisoning?

Alexey Navalny at Moscow rally in 2013. Credit: Wikimedia Commons.

Russian opposition leader Alexei Navalny is likely to survive a suspected poisoning with the nerve agent Novichok, according to the hospital treating him. There have now been at least six known cases of serious Novichok poisoning in the past two years. But only one victim tragically died from it.

Why is that? Is the substance less lethal than previously thought? Or could it be that the stockpile of the nerve agent is degrading?

Nerve agents were discovered through pesticide research. They belong to a group of substances known as organophosphorus chemicals, or “OPs” for short. There are literally thousands of OP substances, many of which can damage the body by inhibiting a family of enzymes known as “cholinesterases” that are critical to regulating the activity of the central nervous system in animals.

OP pesticides are much less toxic to humans than nerve agents because they have been designed to specifically inhibit insect cholinesterases. In contrast, nerve agents target human cholinesterases.

By disrupting the nervous system, Novichok and other nerve agents can kill people through asphyxiation or cardiac arrest. We know they are deadly. The nerve agent Sarin caused multiple casualties in 1995 when it was released in the Tokyo subway.

The nerve agent VX is thought to have killed Kim Jong-nam, the half brother of North Korea’s leader Kim Jong-un, in just 20 minutes after it was allegedly smeared across his face. But all types of nerve agent poisoning can be treated with standard antidotes such as atropine and diazepam.

Little is known about the types of Novichok that have been synthesised or deployed in assassination attempts, other than that they tend to be liquids or powders.

The dose makes the poison

One of the fundamental principles of toxicology was first proposed by a 16th century alchemist, known as Paracelsus, who is often credited with the statement “sola dosis facit venenum”, or “the dose makes the poison”. It means that all substances are capable of being toxic if administered in a sufficient dose. This applies to normally innocuous chemicals such as water, as well as highly toxic materials such as nerve agents.

So have the recent Novichok victims somehow got smaller doses than intended? In the case of the poisoning of Sergei and Yulia Skripal in Salisbury, UK, in 2018, it appears that the poison was initially applied to a door knob.

While the applied dose may have been quite large, possibly equating to several thousand lethal doses, the amount transferred to their skin would have been a fraction of that. The palm of the hand is also one of the least permeable areas of the human body, which would reduce the rate of absorption into the body.

Subsequent contact with other surfaces through normal daily activities would be expected to further reduce the dose on the victims’ hands. This means that the net dose absorbed by the skin would have been relatively small in comparison to the original amount.

In the case of the Skripals, this was still sufficient to cause life-threatening toxicity after a delay of several hours. The fact that they were quickly given appropriate antidotes and supportive therapies was instrumental in their survival.

Two police officers were subsequently also poisoned with the substance when searching Skripals’ home – and both survived. It is possible that they received an even lower dose of Novichok than the Skripals.

Soon after the incident, two more people were poisoned in nearby Amesbury. Tragically, one victim, Dawn Sturgess, died. She had unknowingly sprayed Novichok directly onto her wrist from a perfume bottle her partner had found nearby.

This would undoubtedly have resulted in a much higher dose than the Skripals received and was applied to a thinner, more permeable area of skin. The fact that the onset of poisoning was much faster (minutes) than in the case of the Skripals tends to support this idea.

Sadly, prompt medical treatment was unable to prevent her death. Antidotes can be effective against several multiples of a lethal dose. For example, military antidotes are generally designed to allow survival from at least five lethal doses of a nerve agent. However, no antidote will be effective against a massive dose.

Strurgess’ partner, Charlie Rowley, reportedly spilled some of the contents of the perfume bottle onto his hands, but immediately washed off the oily residue. Immediate decontamination is known to be a highly effective practice against nerve agents and is the recommended initial treatment strategy for chemically contaminated casualties in the UK and USA. It is likely that this action saved the life of Rowley.

In the case of Navalny, it has been reported that he was poisoned through a contaminated cup of tea. As the amount added to the beverage is likely to have been multiples of a lethal dose, how did he survive?

The exact details of the incident are not available, but a variety of factors may have influenced the dose he absorbed. For example, he may just have had just a few sips rather than the whole cup. Initial reports indicate that Navalny also vomited. We also don’t know if the Novichok was adequately dissolved in the tea. These factors may all have contributed to lowering the dose.

The inherent toxicity of nerve agents is a clear attraction to would-be assassins, as are other poisons such as arsenic, cyanide and ricin. However, the practical difficulties in disseminating any type of poison will introduce a wide margin of error in dosing.

Current information suggests that Novichok agents are chemically stable and are manufactured to high purity in specialist production facilities. Therefore, surviving exposure is unlikely to be due to “poor quality” Novichok. The substance is no doubt lethal and has resulted in the death of innocent people as well as the intended victims.The Conversation

Robert Chilcott, Professor, Centre for Research into Topical Drug Delivery and Toxicology, University of Hertfordshire

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Lead exposure might be responsible for 10 times more premature deaths than previously thought

A new study suggests that lead exposure may be responsible for nearly 10 times more deaths in the United States than previously thought.

Credit: Wikipedia.

Scientists have discovered that nearly 412,000 deaths each year in the US can be attributed to lead contamination. That number is ten times higher than the Institute for Health Metrics and Evaluation at the University of Washington in Seattle had previously reported.

“Today, lead exposure is much lower because of regulations banning the use of lead in petrol, paints and other consumer products, so the number of deaths from lead exposure will be lower in younger generations. Still, lead represents a leading cause of disease and death, and it is important to continue our efforts to reduce environmental lead exposure,” explained Professor Bruce Lanphear, from Simon Fraser University in Canada.

Lanphear and colleagues estimated that 28.7% of heart disease-related premature deaths in the US could be caused by lead exposure, which comes to a total of 256,000 deaths annually. 

Researchers used data from the Third National Health and Nutrition Examination Survey, which monitored 14,289 US adults for 20 years. Of the 4,422 participants who died by 2011, approximately 18% of them could have been saved by reducing blood lead concentrations to 1.0 micrograms per deciliter.

Compared to those with low lead blood concentrations, people with high lead levels (over 6.7 micrograms) had the risk of premature death from any cause increased by 37%, the risk of cardiovascular death increased by 70%, and double the risk of death from ischemic heart disease.

“Our study calls into question the assumption that specific toxicants, like lead, have ‘safe levels’, and suggests that low-level environmental lead exposure is a leading risk factor for premature death in the USA, particularly from cardiovascular disease,” Professor Lanphear said in a statement.

Lead exposure can contribute to cardiovascular disease by various pathways. Lead affects the epithelial cells of the blood vessels, which increases the chances of developing plaques that can then cause a heart attack. Lead contamination also leads to kidney damage, which causes high blood pressure and probably acts synergistically with plaque formation.
Also, if you live near an airport, your blood lead levels will be a little higher than if you live farther away due to the lead found in the aviation gas used in single piston jets.

“Estimating the contribution of low-level lead exposure is essential to understanding trends in cardiovascular disease mortality and developing comprehensive strategies to prevent cardiovascular disease. Currently, low levels of lead exposure are an important, but largely ignored risk factor for deaths from cardiovascular disease,” said Professor Lanphear.

The team admits that the study’s principal limitation is that the research relied heavily on one blood concentration measurement taken at the beginning of the study period, almost 20 years ago.
“Our reliance on a single blood test as opposed to serial blood tests means that we have underestimated the impact of lead exposure on cardiovascular disease,” Lanphear said. “There are some things in the study design itself that we really couldn’t change.”

The team urges the retirement of lead-contaminated housing, lead-laden jet fuels, lead water pipes, and the reduction of emissions from smelters and lead battery facilities.

“We’ve made tremendous progress in reducing these exposures in the past four to five decades,” Lanphear added. “But our blood levels are still 10 to 100 times higher than our pre-industrial ancestors,” Lanphear concludes.

Scientific reference: Bruce Lanphear , Stephen Rauch, Peggy Auinger, Ryan W Allen , Richard W Hornung. Low-level lead exposure and mortality in US adults: a population-based cohort studyThe Lancet Public Health, 2018 DOI: 10.1016/S2468-2667(18)30025-2