How do dogs detect high blood sugar? A Comprehensive Guide

How Do Diabetic Service Dogs Help People with Diabetes?

‌If you have diabetes, your body has trouble processing the food you eat and turning it into energy. This means that diabetes can cause your blood sugar levels to build up and reach dangerous levels. This is called hyperglycemia, and it can lead to serious complications, like eye diseases, kidney damage, heart attacks, and strokes.

To treat diabetes, a medicine called insulin can help keep your blood sugar levels from rising too high. But, a common side effect of insulin is hypoglycemia. This means your blood sugar level drops too low. Hypoglycemia can cause seizures and coma, so it’s important to treat it as soon as possible.‌

Dizziness, confusion, and drowsiness are symptoms of both severe hyperglycemia and severe hypoglycemia. A diabetic alert dog is trained to alert you of a blood sugar drop or spike while you’re still awake enough to treat your blood sugar levels or get help.

The way a diabetic service dog tells you that you need to check your blood sugar depends on their training. Some diabetic alert dogs are trained to paw, nudge, lick, or stare at you, while others are taught to jump, bark, or whine. Some dogs have been taught to bring a blood glucose monitor to their owner.

Hope and hype

Gibson says she was influenced by the online marketing campaign of Diabetic Alert Dogs of America, the Nevada company that sold Rocky.

“They have their stories on there about the dogs theyve trained and the people theyve placed them with. And, you know, it [seemed] sound to me,” Gibson says.

If you research diabetic alert dogs, youll find a lot of hope for their role in managing Type 1 diabetes. And youll find a fair amount of hype.

Television news stories about the dogs often uncritically accept their abilities, using words like “incredible” and “amazing.” In fundraising campaigns, would-be alert dog owners position them as critical solutions to their disease.

NPR reviewed nearly 500 active GoFundMe campaigns that mention “diabetic alert dog.” More than a third used phrases like “lifesaver” or “lifesaving.”

How do dogs detect high blood sugar?

Dog training companies make similar claims. Several of them have faced lawsuits or complaints recently from consumers who bought diabetic alert dogs that they say dont work.

In Texas, a group of more than a dozen dog buyers sued a trainer for fraud and won a judgment for $800,000. In Virginia, the attorney general sued a service dog vendor after customer complaints about its dogs, which were marketed as “backed by science” and “100 percent effective.”

The Virginia attorney general claimed that the company, Service Dogs By Warren Retrievers, deceived consumers about the animals abilities and cost, in many cases simply selling “a $25,000 pet.” Company lawyer Glen Franklin Koontz tells NPR his client denies the allegations and calls the lawsuit “baseless.” He stands by the “backed by science” claim and adds: “A fully trained dog is 100 percent effective.”

The reason it might take a lawsuit to fight back against perceived or actual shortcomings in an alert dog is that trainers and dogs generally arent required by any authority or regulator to perform to any particular standards.

While Rocky was marketed as a “certified” alert dog, the certification came only from the company that sold the dog. Soon after Gibson got Rocky, it was clear to her that he wasnt cut out to be a service dog in public, especially in the windy high country of North Carolina.

Gibson says Rocky is easily frightened by common noises such as umbrellas opening and motorcycles passing, and cant work as an alert dog while hes scared.

“The first day that I had him out on my own, the wind blew up. He got so scared that he couldnt run fast enough to try to hide,” Gibson says. “It was just pure fear.”

That was in April 2017, right after she had to sign a series of disclaimers as a condition of getting the dog. One document said Rocky “met her expectations as a diabetic alert dog,” even though she had only two days experience with him.

Another document said Rocky has a “free will” and wasnt guaranteed to do what Gibson and her community paid $15,000 for: alert her to blood sugar changes.

“I answered everything because I was so excited that he was there and I was positive,” Gibson says. “I was hoping everything was going to be wonderful and then after the dust settled, everything wasnt wonderful.”

One paper she signed said Rocky wasnt guaranteed to “perform any specific action at any specific time.”

The sweeping disclaimer might sound at odds with an expensive purchase that people trust with their lives. But research on alert dogs suggests it might also be a reality check about the abilities of diabetic alert dogs in general.

How Are CPL’s Service Dogs for Diabetes Trained?

CPL diabetes alert dogs are trained to detect low blood sugar levels in their early stages, before the blood sugar levels become too dangerous. The dogs are able to do this through smell. There are distinct odors that accompany different blood sugar levels. In order to train our dogs to help those with diabetes, the applicant will take a sample of their saliva on dental cotton when their blood sugar is at 70. This sample is used in training. During the final stages of training, the diabetes alert dog is trained to detect their person’s saliva sample scent. After the dog is fully trained to help their diabetic partner, the pair will attend team training on CPL’s campus in Cochranville, PA for 2 1/2 more weeks of personalized training.

How Do You Teach A Dog To Detect A Diabetic’s Blood Sugar Levels?

When Mary McNeight began training dogs in 2005 to alert low and high blood sugars in people with diabetes (PWDs), she did it for her then-husband, who had type 2 diabetes (T2D) and frequently experienced hypoglycemia.

“So my husband’s dog was completely trained, and I was using him during my first class teaching others how to train their dogs to alert,” explains McNeight, “and my husband’s dog started alerting me.”

McNeight assumed the dog must be confused, and one of the class participants must be going low. So, she asked everyone in the class to check their blood sugar levels. No one was low.

“But the dog kept alerting me,” recalls McNeight, “so I thought, ‘This dog is broken!’ Until I finally checked my blood sugar and sure enough, I was actually low.”

McNeight would soon find out that she too had T2D, and that the “panic disorder” she’d experienced before then was actually hypoglycemia (a lesser-known symptom of prediabetes).

Since then, McNeight has dedicated her career to helping people with type 1 diabetes (T1D) and T2D train their dogs to alert for low and high blood sugars through Service Dog Academy in Illinois, reaching clients across the globe. She also offers a tremendous amount of free education on the subject in this Quick Start Guide and on her Service Dog Academy YouTube channel.

With her help, here we’ll provide an overview of things you should know before seeking out a diabetes alert dog of your own.

While McNeight has spent tens of thousands of dollars on her training in this field, she warns that there is zero regulation on who can call themselves a service dog trainer. Anyone can claim to be an expert in training dogs to sense high and low blood sugars. So, do your research before handing over a single dollar!

“I have a YouTube video on my channel for free to help you spot scams,” explains McNeight. “I also teach in that video what questions to ask any potential service dog resource before giving them any money. This industry is fraught with scammers.”

McNeight warns it’s also filled with basic behavior dog trainers who suddenly think they’ll have a go at diabetes alert training without having any background in this type of training or real knowledge of the condition.

“You don’t want to be their experiment,” says McNeight, who’s reported scammers to the FBI and watched scammers with a nonprofit 501c3 status get shut down after charging $25,000 per dog.

Dr. Dana Hardin, a pioneer researcher in diabetes alert dogs, agrees. An Indianapolis pediatric endocrinologist who served as Eli Lilly’s medical director until her return to clinical care in 2020, Hardin has advocated for years for a standardized method for training and certifying diabetes alert dogs. But that remains an uphill battle, she says.

While she hopes for a standardized system here in the United States, it often comes down to PWDs judging for themselves which programs and trainers are most trustworthy.

She sees the Veteran Affairs Administration (VA) as offering hope. Since they’ve had an increasing number of military veterans applying for dogs trained to alert for PTSD, but no way to know whether the canines actually alerted properly, they have been pushing toward a more standardized certification pathway.

“The biggest issue we still have, so many years later, is the same issue of people claiming to train these alert dogs but not doing an adequate job,” she says.

A legitimate service dog of any kind can easily cost more than $10,000 or $15,000. It depends largely on how much of the training you’re willing to do yourself and where you get your dog from.

The most expensive option is getting a dog that is fully trained, but keep in mind that you’ll still need to train the dog to alert you after this dog becomes yours. Regardless of what stage of training the dog is in when you acquire them, you’ll need to commit time and effort to the process for it to be successful.

McNeight has worked hard to make her training program more affordable, costing anywhere from $1,800 to $3,000 depending on the program you choose. You can do 1-to-1 online training, group classes, or send your dog to McNeight for full-service training.

“The online training during the COVID-19 pandemic has actually been great because I can offer 1-to-1 contact with everybody each week,” says McNeight. “Everyone gets more attention and I don’t have to fly all over the country. I’ve also had students in Australia, Germany, Brazil, etc., because of this online feature.”

Regardless of how much you spend on a service dog, do your homework and make sure they are reputable and legit.

When a person’s blood sugar drops, there are spikes of the chemical isoprene in their breath. It’s believed that dogs can smell this change of chemical makeup on a person’s breath.

“Beyond that it’s something present in our saliva, no one actually knows what the dogs smell when they alert low to high blood sugars,” says McNeight.

In fact, they not only smell the low and high blood sugar, they can smell when you’re rapidly falling or rapidly rising, too, well before you cross the threshold you’ve trained them to acknowledge as low.

“Scientists have many theories, but that’s all they are. Humans cannot replicate what dogs smell because humans have 5 million scent receptors and dogs have 250 million scent receptors,” says McNeight.

However, McNeight explains that all PWDs smell the same way when their owners’ blood sugars are high, low, or rapidly rising or falling — and whatever that smell is, all dogs can smell it.

“Dogs can find whale feces in the ocean,” adds McNeight. “There’s actually a program in the Puget Sound where people search the ocean for whale feces using trained dogs. Dogs can smell a dead body when it’s submerged in deep water. They can also smell human remains from archaeological sites thousands of years old. So, imagine what they can smell when they’re sitting right next to you.”

There are a vast number of dog breeds that are unsuitable for service dog training of any kind. Regardless of how much your loyal canine loves you, they need to fit some critical criteria to be ideal for the job:

A service dog is going to be with you in a variety of public places, which means they need to possess these qualities so they are safe, comfortable, and effective in a variety of environments.

Experts say ideal breeds for a service dog of any kind includes:

This doesn’t mean dogs of other breeds cannot be trained to identify high or low blood sugars. But while a German shepherd is an excellent breed to serve with the police, they aren’t ideal for serving those with medical conditions.

“The public is loud, obnoxious, and unpredictable. You need a dog that can handle that,” says McNeight.

An “imprinted” puppy is a dog that not only comes from a line of service dogs known for their ideal service temperament, they’re also trained from the moment they’re born to associate low blood sugars with food.

“We cover their mother’s nipples with the scent of low blood sugar, so they are getting that positive association with the scent when they are nursing,” explains McNeight. “It makes them more eager to alert because they associate it with eating.”

“The dog needs to first go through basic behavior training, extensive socialization training, and then it’s ready to learn the entire “alert chain,” which can take months,” McNeight says.

Be aware that training a dog for this type of service is a big commitment and it’s highly advisable to work with a professional who comes with solid recommendations.

You will need to collect samples of your spit on sterile cotton balls when your blood sugar is low or high and store them in the freezer — in a secure container that protects them from absorbing other smells — that will be used later during training sessions with your dog.

You yourself decide on the “alert point” by collecting samples when you are below or above a certain high or low blood sugar threshold. Some people may want to be alerted to anything below 100 mg/dL while others may want to be under 70 mg/dL before they’re alerted.

Dogs can be trained to alert in a variety of ways, and depending on what you’re doing, they will adjust their alert accordingly. Dogs can be trained to lick your hand, paw your leg, look at you, or whimper or bark, etc. There isn’t just one alerting method because every circumstance could change the dog’s physical ability to reach you.

For example, if you’re asleep, gently nudging your hand or standing in front of you and whimpering isn’t going to work. In this case, a dog would likely bump their head into you firmly or lick your face to wake you. If you’re driving your car and they are in the back seat, they can’t physically reach you at all, so that would be a useful time for a vocal alert, McNeight explains.

Through a series of detailed steps over the course of many months, a dog can be trained to:

It can take days, weeks, or months. It all depends on the dog and your consistency in training.

“I’ve seen a dog start alerting their owner only 2 days into a class!” says McNeight. “It really depends on the dog and the amount of time you commit to your training. For some dogs it can take 5 days, or 10 weeks.”

It also depends on how you — the person experiencing the low blood sugar — behaves when you’re low.

“If you’re super grumpy when you’re low and you’re not very friendly to your dog during low blood sugar moments either, then they might associate those moments with a negative experience,” warns McNeight. “There are so many variables but the biggest one is committing to the training and being consistent with it, which can easily take 6 months or longer.”

McNeight also points out the difference between, for example, a single woman who lives alone training her dog versus training a dog for a 7-year-old with T1D in a busy home with several other family members living there. If you decide to get a service dog, you’ll need to make space in your life to ensure its training is a major priority.

Specifically, people always wonder about the reliability of these dogs versus using a continuous glucose monitor (CGM).

Through a partnership with Eli Lilly and other scientists, it was the work of Dr. Hardin that led to the first groundbreaking small 2015 study with dogs that diabetes service dogs can, in fact, successfully alert to hypoglycemia.

Hardin believes the dogs are better than a CGM — in part because the dogs can be persistent in alerting versus a device that might go unheard or be inaccurate.

Yet, not all studies have produced positive evidence that service dogs are adequate for alerting to diabetes emergencies.

“For every paper that says it works, there’s another that says it doesn’t,” Hardin tells DiabetesMine. She notes that the studies are inconsistent because methods often can’t be duplicated, or because of unclear training or how the researchers classify a successful alert.

One small 2017 study indicated that the dogs do have a higher rate of false-positive alerts for low blood sugar. But in the context of that research, dog trainer Becky Causey, tells Endocrine Today that dogs may provide a ‘safety net’ to their owners just by having a sense for other important variables.

For her part, trainer McNeight says, “If you had asked me this question 10 years ago, I would’ve said CGMs are crap compared to an alert dog.” But now, she says, CGM technology has improved immensely.

Still, while CGMs have gotten a lot more accurate, “dogs do still give a 20-minute warning of an oncoming low blood sugar moment that a CGM cannot necessarily do,” McNeight adds.

But a CGM might outperform an alert dog at night. McNeight explains that in her experience, only about 70 percent of dogs alert at night, and she finds this is especially true of young dogs.

A puppy isn’t much different from a 2-year-old human: They are growing fast and they need their sleep. This means a young dog can easily sleep through the scent of their owner’s low blood sugars.

For many dogs, they may start alerting during the night once they’re a few years old.

Above all else, McNeight recommends learning how to manage diabetes without a dog first. The patient and family needs to be confident in their disease management skills, and not look to the dog as a solution.

“I will not work with someone who is newly diagnosed, especially if it’s a young child,” says McNeight. “These families need to learn how to manage type 1 diabetes without a dog first — that’s my professional opinion.”

Mara Schwartz, a diabetes care and education specialist and registered dietitian in Greenwood, South Carolina, has lived with T1D for more than 40 years. She trained her dog, Frank, through McNeight’s Diabetes Alert Dog University more than 5 years ago.

“Frank was a puppy, so he needed obedience training, too,” recalls Schwartz. “The alert dog training is a hard process. Low blood sugar moments don’t just happen at the most convenient time. So, it takes a lot of consistency and time commitment.” Mara Schwartz and her dog Frank

“You can’t get frustrated with your dog if they don’t catch on to the training right away,” says Schwartz. “And you can’t force it upon them, or do it for them by bumping your hand on their nose for an alert — they won’t learn it that way.”

Within 6 months, Frank was alerting Schwartz consistently, and alerting her at night by the time he was almost 2 years old.

Frank and Schwartz experienced a very traumatic event in 2017 when her insulin pump malfunctioned. Unbeknownst to Schwartz, her insulin pump had delivered the entire contents of the reservoir — approximately 80 units — into her body while she was at home. The severe low blood sugar came on so quickly that it gave Schwartz no initial physical symptoms, and no time for Frank to alert her.

Instead, she was unconscious and seizing for approximately 5 hours. She awoke to Frank aggressively licking her face and pawing at her, trying to wake her.

“If Frank hadn’t been trying to wake me up, it’s very likely I would’ve been asleep for several more hours,” she says.

It took Schwartz 2 more hours to function enough to get glucose tabs. She had tried to tell her phone to call 911, but her speech was too impaired by the seizures to be comprehensible.

Schwartz survived the seizures because the insulin had eventually cleared from her system and her liver dumped enough stored glucose to keep her alive. But if it weren’t Frank waking her up, she could’ve easily remained on the floor asleep for many more hours, extending the amount of time she was still severely low on blood sugar.

Despite her full recovery, the experience severely traumatized her dog, Frank. He barked when people approached the house. He also whimpered when he couldn’t see Schwartz. She sent him to McNeight for some intensive training to help him recover from the event’s emotional trauma. Now, he’s back at Schwartz’s side doing what he does best: He loves her unconditionally and alerts her to high and low blood sugar levels.