Smoking Is Damaging Your Pet’s Health, Researchers Warn

If you made a New Year’s resolution to stop smoking and are already struggling to stick to it, a new study may offer a further incentive: quitting the habit can benefit your pet’s health as well as your own.
[A cat paw on an ashtray]
Pets in smoking households are at greater risk for weight gain, cell damage, and some cancers, according to researchers.

Smoking is the leading cause of preventable disease and death in the US, accounting for around 1 in 5 deaths annually.

According to the Centers for Disease Control and Prevention (CDC), smoking causes around 90% of all lung cancer deaths in men and women, and it is also a risk factor for heart disease, stroke, and numerous other illnesses.

But it is not only smokers themselves who are at risk of such conditions; since 1964, around 2.5 million non-smokers in the US have died from exposure to secondhand smoke.

With this in mind, it is perhaps unsurprising that pets living in households where someone smokes are at greater risk for poor health.

Previous research from Clare Knottenbelt, professor of small animal medicine and oncology at the University of Glasgow in the UK, and colleagues has shown that dogs living in a smoking household ingest a high amount of tobacco smoke.

For this latest study – which is ongoing – the team set out to investigate how tobacco smoke exposure impacts the health of cats and dogs.

Cats at greatest risk from smoke exposure

Prof. Knottenbelt and colleagues analyzed the nicotine levels in the animals’ fur and looked at whether such levels were associated with any health problems. Additionally, they assessed the testicles of dogs following castration in order to identify any signs of cell damage.

Compared with pets living in non-smoking households, the researchers found that those living in smoking households may be at greater risk of cell damage, some cancers and weight gain.

Cats are most at risk, according to the researchers, because they ingest more smoke than dogs – regardless of whether or not they have access to outdoors. The team speculates that this may be down to the extensive self-grooming cats engage in, causing them to ingest more tobacco toxins.

When analyzing the testicles of castrated dogs from smoking households, the researchers identified a gene that represents a sign of cell damage that is related to some cancers.

Furthermore, they found that dogs that lived in smoking households gained more weight after being neutered than dogs from non-smoking households.

Stopping smoking completely ‘best for pets’ health and well-being’

However, the researchers also found that these risks reduced when owners smoked outside, therefore reducing the amount of smoke their pets ingested.

While owners who reduced the number of cigarettes they smoked per day did reduce pets’ smoke exposure, it was not eliminated completely; cats from households that reduced their cigarette intake to less than 10 daily still had higher nicotine levels in their fur than those from non-smoking households.

The team suggests that pets may even be at greater risk of health problems from smoke exposure than children in smoking households, noting that because pets are lower in height, they are more likely to ingest third-hand smoke – that is, tobacco chemicals present in carpets and other surfaces.

While the research is ongoing, the team believes the results to date should act as a warning to smokers with pets. Prof. Knottenbelt says:

“As well as the risk to the smoker, there is the danger of secondhand smoke to others. Pet owners often do not think about the impact that smoking could have on their pets.

Whilst you can reduce the amount of smoke your pet is exposed to by smoking outdoors and by reducing the number of tobacco products smoked by the members of the household, stopping smoking completely is the best option for your pet’s future health and well-being.”

So, the next time you get the urge to light up and break that New Year’s resolution, just spare a thought for the health of your four-legged friend.

Contagious Canine Cancer: How It Evolved Over 2,000 Years

The canine transmissible venereal tumor is a contagious form of cancer that is common in dog populations across the globe. In a new study, researchers have uncovered surprising information on how this cancer has evolved, and the findings could shed light on the evolution of cancer in humans.
[A dog with a stethoscope]
CTVT is primarily spread in dogs through mating, though it can also be spread through licking, sniffing, or giving birth.

Canine transmissible venereal tumor (CTVT) is cancer that is most commonly passed between dogs through mating.

CTVT most commonly arises in the form of genital tumors. When an infected dog mates, it passes on living tumor cells. These tumor cells can also be passed on through licking, sniffing, or giving birth.

Arising more than 11,000 years ago from the cells of a single dog – referred to as the “founder dog” – CTVT is one of the oldest known cancers.

According to researchers from the University of Cambridge in the United Kingdom, all CTVT tumors consist of DNA that belongs to the founder dog.

By analyzing the CTVT tumors of dogs across the globe, researchers can pinpoint and analyze mutations that these tumors have acquired over time, enabling them to determine the origins of the disease and when and how it spread.

Building an ‘evolutionary family tree’ of CTVT

For this latest study – published in eLife – co-first author Andrea Strakova, of the Department of Veterinary Medicine at Cambridge, and colleagues analyzed the DNA of mitochondria in the CTVT tumors of 449 dogs from 39 countries.

Mitochondria are commonly referred to as the “powerhouses” of cells, providing cells with the energy they need to function.

According to Strakova and colleagues, previous studies have suggested that among dogs infected with CTVT, there have been occasions when mitochondrial DNA (mtDNA) has transferred to their tumors.

As such, this mtDNA has been transferred to the tumor cells of dogs that are subsequently infected.

The team’s latest analysis of CTVT tumors revealed that the mtDNA transfer process between CTVT-infected dogs and their tumors has occurred at least five times over the past 2,000 years – a process that the researchers suggest may have arisen to aid tumor survival.

This discovery enabled the team to create an “evolutionary family tree” consisting of five branches known as “clades.” Each clade represents a point in time when mtDNA was transferred between CTVT-infected dogs and their tumors.

Identifying the geographical location of the tumors within each clade enabled the researchers to pinpoint how CTVT has spread worldwide.

CTVT-infected dogs accompanied humans on travels at sea

The evolutionary family tree suggests that – because of the distance and speed that CTVT spread – dogs often accompanied humans on their sea travels.

“The extensive and recent global expansion detected in the CTVT lineage is consistent with signals of widespread admixture observed in worldwide populations of domestic dogs, highlighting the extent to which canine companions accompanied human travelers on their global explorations,” the authors explain.

They point to one clade of the evolutionary tree that suggests CTVT may have spread from Russia or China approximately 1,000 years ago.

However, it is likely that the disease only arose in the Americas around 500 years ago, which suggests that European colonialists – known to have traveled with dogs – brought it with them.

Additionally, the evolutionary tree suggests that CTVT arrived in Australia at the beginning of the 20th century and that it was likely brought into the country by infected dogs that accompanied European settlers.

‘Recombination’ process identified in cancer for the first time

As well as shedding light on the evolutionary history of CTVT, the researchers uncovered interesting information on the mechanisms by which mtDNA transfers to the tumors of dogs with CTVT.

The team found that mtDNA molecules from the healthy cells of CTVT-infected canines that have transferred to tumor cells sometimes mix with the mtDNA within tumor cells – a process referred to as “recombination.”

According to Strakova and colleagues, such a process has never before been observed in cancer, and the discovery indicates that it may not only be the cancer cells of dogs that are subject to recombination.

“Mitochondrial DNA recombination could be happening on a much wider scale, including in human cancers, but it may usually be very difficult to detect,” says co-first study author Máire Ní Leathlobhair, of the Department of Veterinary Medicine at Cambridge.

“When recombination occurs in transmissible cancers, two potentially very different mitochondrial DNAs – one from the tumor, one from the host – are merging and so the result is more obvious,” she explains.

“In human cancer, the tumor’s mitochondrial DNA is likely to be very similar to mitochondrial DNA in the patient’s normal cells, so the results of recombination would be almost impossible to recognize.”

At present, the researchers are unclear what significance this recombination discovery has. Still, they are planning to investigate whether it plays a role in cancer cell survival and whether inhibiting the process could halt cancer cell growth.

“The genetic changes in CTVT have allowed us to reconstruct the global journeys taken by this cancer over 2,000 years.

It is remarkable that this unusual and long-lived cancer can teach us so much about the history of dogs, and also about the genetic and evolutionary processes that underlie cancer more generally.”

Senior author Dr. Elizabeth Murchison

Dog Sledding Offers A Healthy Dose Of Adventure For Children With Cancer

A team of sled dogs racing through the snowy forests of northern Canada conjures up the timeless spirit of exploration. But the intrepid youths on the sleds may not be exactly what you’re picturing – they’re young girls and boys with cancer.

Young Patient Bonds with Sled Dog
A young cancer patient bonds with a sled dog as part of an expedition organized by Sourire à la Vie
Credit: Credit to Emmanuelle Compte

A common perception of the pediatric cancer patient is a frail youth whose childhood experiences are tragically curtailed by the disease. Now, the results of a new preliminary study published in ecancermedicalscience show that children with cancer may benefit from a different kind of treatment – a healthy dose of adventure.

The study follows eleven children aged 10-18 years, and five chaperones including doctors and nurses, on an expedition organized by the French non-profit Sourire à la Vie, which supports the use of adapted physical activity for young cancer patients.

“What I learned from this study is that we doctors have the false belief that kids with cancer cannot practice sport because they are too tired or weak from their treatments,” says the corresponding author of the study, Dr. Nicolas André. He’s a pediatric oncologist at the Assistance Publique Hôpitaux de Marseille, France.

“These perceptions are at least partly wrong,” Dr. André says. “Adapted physical activities can be performed by most children with cancer even during their treatment, and can bring a lot to children.”

All of the eleven children received adapted physical training and exercises before the expedition. The children successfully completed the program without harm – and they demonstrated statistically significant improvement in both physical and psychological health.

The children participated in other activities, such as snow exercises, as well as caring for the sled dogs.

“One of the main reasons why we chose dog sledding was to create a unique sportive experience based on the change of scenery and building a strong relationship with animals,” explains study author Frédéric Sotteau, founder of Sourire à la Vie.

The health and safety of the children were of paramount concern, Sotteau says. “We did not compromise regarding security, so we carefully prepared the expedition hand-in-hand with Canadian associations and doctors.”

“Based on our work over the last eight years, we all are convinced that practicing adapted physical activity is very positive for children with cancer,” comments study author Professor Laurent Grélot, a researcher at Aix-Marseille University, France. “It avoids cardiovascular and muscular deconditioning can decrease treatment-induced fatigue, and can help maintaining social integration.”

“It is now time to demonstrate these results.”

Based on the success of this study, the researchers have collected enough funding to initiate a randomized trial to evaluate the benefits of adapted physical activities for children with cancer. But perhaps the best take-home message comes from the children themselves.

“Before my cancer diagnosis, I used to do a lot of sport, but then I lost self-confidence and my body was not able to cope with physical efforts,” says Merwan, an 18-year-old patient. “This trip in Canada transformed me. I am in shape again, and now I know I am able to practice sport again.”

“I have been dog sledding for 6 hours a day,” adds Nell, a 12-year-old patient. “I am very proud, and I feel so good now.”

Pilot evaluation of physical and psychological effects of a physical trek program including a dog sledding expedition in children and teenagers with cancer. ecancer 9 558 / DOI: 10.3332/ecancer.2015.558


Source: EurekAlert!, the online, global news service operated by AAAS, the science society

Therapy Dogs Have Calming Effect On Children Having Cancer Treatment

There are many stories of the positive effect that therapy dogs can have on children with cancer and their families. But until now, there has been little hard scientific evidence to back them up.
young girl with dog
The study suggests therapy dogs can have a calming effect on young cancer patients.

A new trial presents some of the first solid data to support anecdotal reports of the positive impact dog therapy programs can have on children with cancer and their families.

The preliminary findings are to be presented at the American Academy of Pediatrics National Conference & Exhibition in Washington, DC, on Sunday, October 25th.

Around 1 in 285 children in the US will be diagnosed with cancer before the age of 20. Survival rates for kids with cancer have improved dramatically in past decades. The number who die within 5 years of diagnosis has declined by more than 50% from 1975-1977 to 2007-2010.

However, this improvement has not been matched by evidence of what can be done to improve quality of life for these young patients and their families.

Therapy dogs are an example of animal-assisted therapy (AAT), where animals form part of the treatment of human patients. The aim is to improve the patient’s social, emotional or mental functioning and well-being.

Many hospitals now have therapy dogs that visit patients and their families, and the new trial takes place at five such hospitals in the US.

‘The therapy dog may have a calming effect on the patient’

The new study is part of the Canines and Childhood Cancer (CCC) research project run by the American Humane Association and funded by Zoetis – an independent global animal health company, formerly part of Pfizer.

The project is looking at the effects of AAT on the child, the family and also the therapy dog.

Measures of blood pressure, pulse rates and anxiety levels are collected before and after a weekly visit from the therapy dog. During the visits, the children pet or talk to their therapy dog, brush its coat, look at photos of the dog, watch it perform tricks and obey commands and learn about dog breeds.

Preliminary results show that blood pressure readings in the groups receiving AAT interventions remained more stable across all sessions than in the control group that did not receive AAT, notes lead researcher Dr. Amy McCullough, national director of humane research and therapy for the American Humane Association.

The researchers also found a higher degree of variability in heart rate in the control group patients than in the patients who received AAT interventions. Dr. McCullough says:

“These findings suggest that the dog may have a calming effect on the patient.”

The following video describes the purpose and history of the CCC project and gives some examples of therapy dogs and the patients who can benefit from them:

Therapy dogs also had calming effect on the parents

So far, the trial has enrolled 68 children diagnosed with cancer of ages ranging from 3-17 years. Thirty-nine of the children are in the treatment group and 29 are in the control group. The researchers expect to enroll around the same number again before the study ends in 2016.

The preliminary findings also suggest that the therapy dogs have a calming effect on the parents of the young patients.

Parents of children in the control group reported fluctuating anxiety levels with peaks and troughs, while parents in the treatment group showed more stable anxiety levels and even a slight decline as they approached the end of their involvement in the study.

Overall, the children in both groups saw a fall in anxiety over the course of their involvement in the study.

The researchers are also investigating the effect of the intervention on the dogs, looking at their temperament and behavior during the visits. Dr. McCullough concludes:

“This study will be a milestone in understanding of the benefits of the vital bond shared between people and animals.”

She says she and her colleagues hope the results will increase the use of therapy dogs and enhance their training and practice, as well as improve outcomes for children and families facing the challenges of childhood cancer.

The new study follows another that Medical News Today reported earlier this year by researchers at Mount Sinai Beth Israel, who found hard evidence that therapy dogs improve the emotional well-being of adult cancer patients undergoing complex treatments. Some of the cancer patients at the New York hospital said they would have stopped their treatment before completion had it not been for the presence of the certified therapy dog and volunteer handler.