Nancy Dreschel, Penn State

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to CuriousKidsUS@theconversation.com.

Why do dogs love to play with trash? – Sarah G٫ age 11٫ Seguin٫ Texas

When I think about why dogs do something, I try to imagine what motivates them. What does a dog get out of playing with trash? As a veterinarian and a professor who teaches college students about companion animals, I believe there’s an easy answer: Garbage smells delicious and tastes good to dogs.

Dogs have an amazing sense of smell. They have 300 million receptors for smell in their noses, while humans have only 6 million. People can make use of this sniffing ability to train dogs to detect illegal drugs, explosives and endangered species, and to help locate people lost in the woods.

While you might not like how your trash smells, to your dog it is an appealing buffet brimming with apple cores, banana peels, meat scraps and stale bread. Even used napkins and paper towels are tempting to dogs, when they are smeared with and carry the smell of yesterday’s lunch.

Because dogs can find trace amounts of explosives or a person buried under 6 feet (1.8 meters) of snow after an avalanche, they are certainly capable of locating last night’s pizza crust and chicken bones in the kitchen garbage can.

Sometimes it’s hard to see what the attraction is. My Australian cattle dog mix, Sparky, loves to eat used tissues – gross, right?

Even empty cans smell inviting to dogs. Trash cans in kitchens and bathrooms are often at their nose level, too, making for easy access. Add to that the fact that if the dog got into the garbage once and found something tasty, they will likely keep searching with the hope of being rewarded again.

Thrill of the hunt

Searching and digging around for food is natural for dogs because it provides some of the thrill of the hunt, even if they just ate and aren’t hungry.

The most successful prehistoric dogs ate the bones and scraps that humans left behind more than 10,000 years ago. Hanging around humans and their garbage was a way they could get plenty to eat. Even your pup today has some of those same old searching instincts.

While our trash has changed from the days of hunting and gathering, the discarded paper napkins, plastic wrappers and food scraps we throw away all still smell like food to dogs. And this scavenging behavior is still hardwired in our pampered pets. Although it may look to us like they’re playing, our dogs’ sniffing out and tearing things up from the trash and tossing them around mimics what their ancestors did when they tugged on and tore up an animal carcass they had found.

Many people take advantage of this instinct and use “snuffle mats” – cloth or paper where food is hidden – or puzzle feeding toys to keep their pups’ minds active. Having to hunt for and find their food helps them use their noses and sharpens their skills.

Annoying or even dangerous

While spreading trash all over the home may be natural for dogs, cleaning it up is no fun for the people they live with. And if your dog pokes its nose in a garbage can, it could be in danger. Eating plastic bags, string, chicken bones, chemicals or rotten food can cause blockages, diarrhea and poisoning. Commonly referred to as “garbage gut,” garbage poisoning can be life-threatening.

I’ve treated dogs that cut their tongues and mouths on cans or broken glass. I once performed surgery to remove a corncob from the intestines of a dog that had eaten it a month earlier. He was certainly relieved when he woke up.

How can you keep your dogs away from the trash?

It can be hard to train a dog to leave garbage alone, especially if they have found a tasty morsel or two by raiding the trash can in the past. I recommend that you invest in a garbage can with a lid closed by a latch that they can’t open. If that fails, you can put garbage – especially food scraps – out of reach in a closet, cupboard or behind a closed door.

My trash cans are all behind closed doors, and the bathroom doors are always shut, which also keeps my cat, Penny, from unrolling the toilet tissue. But that’s another story. Our kitchen trash is in a latched cupboard.

No one knows exactly what goes through dogs’ minds. And yet looking at what motivates your canine companion and how dog behaviors have evolved may help explain why these animals do the things they do.

Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell us your name, age and the city where you live.

And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.

Nancy Dreschel, Associate Teaching Professor of Small Animal Science, Penn State

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

Eleanor Rivera, University of Illinois Chicago

For a disease afflicting 35.5 million people in the U.S., chronic kidney disease flies under the radar. Only half the people who have it are formally diagnosed.

The consequences of advanced chronic kidney disease are severe. When these essential organs can no longer do their job of filtering waste products from the blood, patients need intensive medical interventions that gravely diminish their quality of life.

As an assistant professor of nursing and an expert in population health, I study strategies for improving patients’ awareness of chronic kidney disease. My research shows that patients with early-stage chronic kidney disease are not getting timely information from their health care providers about how to prevent the condition from worsening.

Here’s what you need to know to keep your kidneys healthy:

What do your kidneys do, and what happens when they fail?

Kidneys have multiple functions, but their most critical and unglamorous job is filtering waste out of the body. When your kidneys are working well, they get rid of everyday by-products from your normal metabolism by creating urine. They also help keep your blood pressure stable, your electrolytes balanced and your red blood cell production pumping.

The kidneys work hard around the clock. Over time, they can become damaged by acute experiences like severe dehydration, or acquire chronic damage from years of high blood pressure or high blood sugar. Sustained damage leads to chronically impaired kidney function, which can eventually progress to kidney failure.

Kidneys that have failed stop producing urine, which prevents the body from eliminating fluids. This causes electrolytes like potassium and phosphate to build up to dangerous levels. The only effective treatments are to replace the work of the kidney with a procedure called dialysis or to receive a kidney transplant.

Kidney transplants are the gold standard treatment, and most patients can be eligible to receive them. But unless they have a willing donor, they can spend an average of five years waiting for an available kidney.

Most patients with kidney failure receive dialysis, which artificially replicates the kidneys’ job of filtering waste and removing fluid from the body. Dialysis treatment is extremely burdensome. Patients usually have to undergo the procedure multiple times per week, with each session taking several hours. And it comes with a major risk of death, disability and serious complications.

What are the risk factors of chronic kidney disease?

In the U.S., the biggest contributors to developing chronic kidney disease are high blood pressure and diabetes. Up to 40% of people with diabetes and as many as 30% of people with high blood pressure develop chronic kidney disease.

The problem is, as with high blood pressure, people with early-stage chronic kidney disease almost never experience symptoms. Clinicians can test a patient’s overall kidney function using a measure called the estimated glomerular filtration rate. Current guidelines recommend that everyone – particularly people with risk factors like high blood pressure and diabetes – get their kidney function routinely tested to ensure the condition doesn’t progress silently.

Early treatment for kidney disease often relies on managing high blood pressure and diabetes. New medications called SGLT2 inhibitors, originally developed to treat diabetes, may be able to directly protect the kidneys themselves, even in people who don’t have diabetes.

Patients with early-stage kidney disease can benefit from knowing their kidney function scores and from treatment innovations like SGLT2 inhibitors, but only if they are successfully diagnosed and can discuss treatment options during routine visits with their health care providers.

What are some barriers to early treatment?

Early treatment for chronic kidney disease often gets overlooked during routine clinical care. In fact, as many as one-third of patients with kidney failure have no record of health care treatment for their kidneys in the early stages of their disease.

Even if a diagnosis for chronic kidney disease is noted in a patient’s medical record, their provider might not discuss it with them: As few as 10% of people with the disease are aware that they have it.

That’s partly due to the constraints of the U.S. health care system. The diagnosis, treatment and monitoring of early-stage chronic kidney disease occurs mostly in the primary care setting. However, primary care visit time is limited by insurance company reimbursement policies. Especially with patients who have multiple health problems, doctors may prioritize more noticeably pressing concerns.

The result is that many clinicians put off addressing chronic kidney disease until symptoms emerge or test results worsen, often leaving early-stage patients undiagnosed and poorly informed about the disease. Research shows that people who are nonwhite, female and of lower socioeconomic status or education level are most likely to fall into this gap.

But patients are eager for this knowledge, according to a study I co-authored. I interviewed patients who had early-stage kidney disease about their experiences receiving care. In their responses, patients expressed dissatisfaction with the lack of information they received from their health care providers and voiced a strong interest in learning more about the disease.

As kidney disease progresses to the later stages, patients get treated by kidney specialists called nephrologists, who provide patients with targeted treatment and more robust education. But by the time patients progress to late-stage disease or even kidney failure, many symptoms can’t be reversed and the disease is much harder to manage.

How can patients take charge of kidney health?

People who are at risk for chronic kidney disease or who have developed early-stage disease can take several steps to minimize the chances that it will progress to kidney failure.

First, patients can ask their doctors about chronic kidney disease, especially if they have risk factors such as high blood pressure or diabetes. Studies show that patients who ask questions, make requests and raise concerns with their provider during their health care visit have better health outcomes and are more satisfied with their care.

Some specific questions to ask include “Am I at risk of developing chronic kidney disease?” and “Have I been tested for chronic kidney disease?” To help patients start these conversations at the doctor’s office, researchers are working to develop digital tools that visually represent a patient’s kidney disease test results and risks. These graphics can be incorporated into patients’ medical records to help spur conversations during a health care visit about their kidney health.

Studies show that patients with chronic kidney disease who have a formal diagnosis in their medical records receive better care in line with current treatment guidelines and experience slower disease progression. Such patients can ask, “How quickly is my chronic kidney disease progressing?” and “How can I monitor my test results?” They may also want to ask, “What is my treatment plan for my chronic kidney disease?” and “Should I be seeing a kidney specialist?”

In our research, we saw that patients with chronic kidney disease who had seen a loved one experience dialysis treatment were especially motivated to stick with their treatment to prevent kidney failure.

But even without the benefit of direct experience, the possibility of kidney failure may motivate patients to follow their health care providers’ recommendations to eat a healthy diet, get regular physical activity and take their medications as prescribed.

Eleanor Rivera, Assistant Professor of Population Health Nursing Science, University of Illinois Chicago

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

Gabrielle Principe, College of Charleston

In 1990, George Franklin was convicted of murder and sentenced to life in prison based on the testimony of his 28-year-old daughter Eileen. She described seeing him rape her best friend and then smash her skull with a rock.

When Eileen testified at her father’s trial, her memory of the murder was relatively fresh. It was less than a year old. Yet the murder happened 20 years earlier, when she was 8 years old.

How can you have a one-year-old memory of something that happened 20 years ago? According to the prosecution, Eileen repressed her memory of the murder. Then much later she recovered it in complete detail.

Can a memory of something so harrowing disappear for two decades and then resurface in a reliable form?

This case launched a huge debate between memory researchers like me who argue there is no credible scientific evidence that repressed memories exist and practicing clinicians who claim that repressed memories are real.

This controversy is not merely an academic one. Real people’s lives have been shattered by newly recollected traumatic experiences from childhood. I’ve seen this firsthand as a memory expert who consults on legal cases involving defendants accused of crimes they allegedly committed years or even decades ago. Often the only evidence linking the defendant to the crime is a recovered memory.

But the scientific community disagrees about the existence of the phenomenon of repressed memory.

Freud was the father of repression

Nineteenth-century psychoanalytic theorist Sigmund Freud developed the concept of repression. He considered it a defense mechanism people use to protect themselves from traumatic experiences that become too overwhelming.

The idea is that repression buries memories of trauma in your unconscious, where they – unlike other memories – reside unknown to you. They remain hidden, in a pristine, fixed form.

In Freud’s view, repressed memories make themselves known by leaking out in mental and physical symptoms – symptoms that can be relieved only through recovering the traumatic memory in a safe psychological environment.

In the 1980s, increasing numbers of therapists became concerned about the prevalence of child sexual abuse and the historical tendencies to dismiss or hide the maltreatment of children. This shift gave new life to the concept of repression.

Rise of repressed memory recovery

Therapists in this camp told clients that their symptoms, such as anxiety, depression or eating disorders, were the result of repressed memories of childhood sexual abuse that needed to be remembered to heal. To recover these memories, therapists used a range of techniques such as hypnosis, suggestive questioning, repeated imagining, bodywork and group sessions.

Did recovered-memory therapy work? Many people who entered therapy for common mental health issues did come out with new and unexpected memories of childhood sexual abuse and other trauma, without physical evidence or corroboration from others.

But were these memories real?

The notion of repressed memories runs counter to decades of scientific evidence demonstrating that traumatic events tend to be very well remembered over long intervals of time. Many victims of documented trauma, ranging from the Holocaust to combat exposure, torture and natural disasters, do not appear to be able to block out their memories.

In fact, trauma sometimes is too well remembered, as in the case of post-traumatic stress disorder. Recurrent and intrusive traumatic memories are a core symptom of PTSD.

No memory ≠ repressed memory

There are times when victims of trauma may not remember what happened. But this doesn’t necessarily mean the memory has been repressed. There are a range of alternative explanations for not remembering traumatic experiences.

Trauma, like anything you experience, can be forgotten as the result of memory decay. Details fade with time, and retrieving the right remnants of experience becomes increasingly difficult if not impossible.

Someone might make the deliberate choice to not think about upsetting events. Psychologists call this motivated forgetting or suppression.

There also are biological causes of forgetting such as brain injury and substance abuse.

Trauma also can interfere with the making of a memory in the first place. When stress becomes too big or too prolonged, attention can shift from the experience itself to attempts to regulate emotion, endure what’s happening or even survive. This narrow focus can result in little to no memory of what happened.

False memories

If science rejects the notion of repressed memories, there’s still one question to confront: Where do newly recollected trauma memories, such as those triggered in recovered-memory therapy, come from?

All memories are subject to distortions when you mistakenly incorporate expectations, assumptions or information from others that was not part of the original event.

Memory researchers contend that memory recovery techniques might actually create false memories of things that never happened rather than resurrect existing memories of real experiences.

To study this possibility, researchers asked participants to elaborate on events that never happened using the same sorts of suggestive questioning techniques used by recovered-memory therapists.

What they found was startling. They were able to induce richly detailed false memories of a wide range of childhood traumatic experiences, such as choking, hospitalization and being a victim of a serious animal attack, in almost one-third of participants.

These researchers were intentionally planting false memories. But I don’t think intention would be necessary on the part of a sympathetic therapist working with a suffering client.

Are the memory wars over?

The belief in repressed memories remains well entrenched among the general public and mental health professionals. More than half believe that traumatic experiences can become repressed in the unconscious, where they lurk, waiting to be uncovered.

This remains the case even though in his later work, Freud revised his original concept of repression to argue that it doesn’t work on actual memories of experiences, but rather involves the inhibition of certain impulses, desires and fantasies. This revision rarely makes it into popular conceptions of repression.

As evidence of the current widespread belief in repressed memories, in the past few years several U.S. states and European countries have extended or abolished the statute of limitations for the prosecution of sexual crimes, which allows for testimony based on allegedly recovered memories of long-ago crimes.

Given the ease with which researchers can create false childhood memories, one of the unforeseen consequences of these changes is that falsely recovered memories of abuse might find their way into court – potentially leading to unfounded accusations and wrongful convictions.

Gabrielle Principe, Professor of Psychology, College of Charleston

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