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The relationship between number of training sessions per week and learning in dogs - this article is behind a paywall :(

Iben Meyer, Jan Ladewigcorrespondenceemail

Department of Large Animal Science, Faculty of Life Sciences, University of Copenhagen, Grønnegårdsvej 8, 1870 Frederiksberg C, Denmark

...here the 'free' version: http://scentdogsaustralia.com/uploads/3/4/6/0/34604456/number_of_training_sessions_and_learning_in_dogs.pdf

Note: no matter what search engine you use (Google, Bing, Yahoo....) they are all biased and aim to earn some money somehow...so depending on the topic the search engine will likely rank goods you have to pay for higher than free goods...

if you find an article you have to pay for: do a second search (perhaps with a different search engine) and enter just the title and you might find the article without having to pay for it.

ETA:...keep in mind that a) the owner of the site that provides the 'free' article so it can be accessed via such an alternative link and / or b) the download of the particular article from this site might still violate 'fair use' and therefore proprietary rights.

Edited by Willem
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  • 3 weeks later...

Thanks Willem

This one just came out so no free copies yet. However one of the scientists wrote a plain english article on the study to tide people over in the meantime

Neurobiology of Self-Control in Dogs

New brain imaging study shows brain region for canine impulse control.

Some snippets, worth reading the whole thing for training mpulse control ideas:

...To study self-control, we trained our Atlanta cohort of MRI-dogs on a psychological test commonly used with children. It is called the Go-NoGo test. We taught the dogs to nosepoke a target in response to a whistle.

This was the “Go” condition. This was surprisingly easy to train. Once the dogs had this down, we then introduced the “NoGo” condition. This was a new hand signal in which the arms were raised in an ‘X.’ This meant, “Don’t nosepoke, even when you hear the whistle.” The NoGo condition was harder for the dogs to learn and took 2-4 months of training...

We even tested the dogs on a different test of self-control with something called the “A not B” test. This is an old experiment, originally conceived by Jean Piaget as a test of object permanence in human infants. In the A not B test, a dog watches a human place a piece of food in one of three buckets (the A location). She is then released to retrieve the food. This is done three times in the same location, and then, in full view of the dog, the food is moved to a new bucket (the B location). Because the dog has developed a tendency to go one way, they must now override it and go to the new bucket. Sounds simple, but children younger than 9 months can’t do it, and dogs vary widely in their performance.

Interestingly, we found that dogs who did better on the Go-NoGo test did better on the A not B test. This means that there is consistency across different tests of self-control, but dogs vary in their ability to do them. We think this has to do with their underlying brain function.

The science article:

Neurobehavioral evidence for individual differences in canine cognitive control: an awake fMRI study

Based on behavioral evidence, the domestic dog has emerged as a promising comparative model of human self-control. However, while research on human inhibition has probed heterogeneity and neuropathology through an integration of neural and behavioral evidence, there are no parallel data exploring the brain mechanisms involved in canine inhibition. Here, using a combination of cognitive testing and awake neuroimaging in domestic dogs, we provide evidence precisely localizing frontal brain regions underpinning response inhibition in this species and demonstrate the dynamic relationship between these regions and behavioral measures of control. Thirteen dogs took part in an in-scanner go/no-go task and an out-of-scanner A-not-B test. A frontal brain region was identified showing elevated neural activity for all subjects during successful inhibition in the scanner, and dogs showing greater mean brain activation in this region produced fewer false alarms. Better performance in the go/no-go task was also correlated with fewer errors in the out-of-scanner A-not-B test, suggesting that dogs show consistent neurobehavioral individual differences in cognitive control, as is seen in humans. These findings help establish parity between human and canine mechanisms of self-control and pave the way for future comparative studies examining their function and dysfunction
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  • 2 weeks later...

Epidemiological Study of Mammary Tumors in Female Dogs Diagnosed during the Period 2002-2012: A Growing Animal Health Problem

Yaritza Salas,Adelys Márquez, Daniel Diaz, and Laura Romero

Tiffany Seagroves, Academic Editor

Epidemiological studies enable us to analyze disease behavior, define risk factors and establish fundamental prognostic criteria, with the purpose of studying different types of diseases. The aim of this study was to determine the epidemiological characteristics of canine mammary tumors diagnosed during the period 2002-2012. The study was based on a retrospective study consisting of 1,917 biopsies of intact dogs that presented mammary gland lesions. Biopsies were sent to the Department of Pathology FMVZ-UNAM diagnostic service. The annual incidence of mammary tumors was 16.8%: 47.7% (benign) and 47.5% (malignant). The highest number of cases was epithelial, followed by mixed tumors. The most commonly diagnosed tumors were tubular adenoma, papillary adenoma, tubular carcinoma, papillary carcinoma, solid carcinoma, complex carcinoma and carcinosarcoma. Pure breeds accounted for 80% of submissions, and the Poodle, Cocker Spaniel and German Shepherd were consistently affected. Adult female dogs (9 to 12 years old) were most frequently involved, followed by 5- to 8-year-old females. Some association between breeds with histological types of malignant tumors was observed, but no association was found between breeds and BN. Mammary tumors in intact dogs had a high incidence. Benign and malignant tumors had similar frequencies, with an increase in malignant tumors in the past four years of the study. Epithelial tumors were more common, and the most affected were old adult females, purebreds and small-sized dogs. Mammary tumors in dogs are an important animal health problem that needs to be solved by improving veterinary oncology services in Mexico.
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Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers:



...For females, the timing of neutering is more problematical
because early neutering significantly increases the incidence rate of CCL from near
zero to almost 8 percent
, and
late neutering increases the rates of HSA to 4 times that of the 1.6 percent rate for intact females
and to 5.7 percent for MCT, which was not diagnosed in intact females

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Neutering of German Shepherd Dogs: associated joint disorders, cancers and urinary incontinence

Link to article


German Shepherd Dogs are important in police and military work, and are a popular family pet. The debilitating joint disorders of hip dysplasia, cranial cruciate ligament tear (CCL) and elbow dysplasia can shorten a dog’s useful working life and impact its role as a family member. For this study, veterinary hospital records were examined over a 14.5-year period on 1170 intact and neutered (including spaying) German Shepherd Dogs for joint disorders and cancers previously associated with neutering. The diseases were followed through 8 years of age, with the exception of mammary cancer (MC) in females that was followed through 11 years. The cancers followed, apart from mammary, were osteosarcoma, lymphoma, hemangiosarcoma and mast cell tumour. In intact males, 7% were diagnosed with one or more joint disorders, while in males neu-tered prior to a year of age, a significantly higher 21% were diagnosed with one or more joint disorders. Inintact females, 5% were diagnosed with one or more joint disorders, while in females neutered prior to a year of age, this measure was significantly increased to 16%. The increased joint disorder incidence mostly associated with early neutering was CCL. MC was diagnosed in 4% of intact females compared with less than 1% in females neutered before 1 year. The occurrence of the other cancers followed through 8 years of age was not higher in the neutered than in the intact dogs. Urinary incontinence, not diagnosed in intact females, was diagnosed in 7% of females neutered before 1 year, a significant difference. These findings, pro-filing the increase in joint disorders associated with early neutering, should help guide the timing of neutering for this breed.

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This came out today so no direct link to the study yet.

Genomic and archaeological evidence suggests a dual origin of domestic dogs. Science, 2016; 352 (6290): 1228 DOI: 10.1126/science.aaf3161

A link to a an article on the study

The question, 'Where do domestic dogs come from?', has vexed scholars for a very long time. Some argue that humans first domesticated wolves in Europe, while others claim this happened in Central Asia or China. A new paper, published in Science, suggests that all these claims may be right. Supported by funding from the European Research Council and the Natural Environment Research Council, a large international team of scientists compared genetic data with existing archaeological evidence and show that man's best friend may have emerged independently from two separate (possibly now extinct) wolf populations that lived on opposite sides of the Eurasian continent. This means that dogs may have been domesticated not once, as widely believed, but twice.

2 minutes later the site recommended this study to me :laugh:

Cranial Shape and the Modularity of Hybridization in Dingoes and Dogs; Hybridization Does Not Spell the End for Native Morphology. Evolutionary Biology, 2016; DOI: 10.1007/s11692-016-9371-x

Link to article, only published recently

Australia's largest predator, the dingo, is resistant to one of the main threats to its survival as a species -- changes to skull shape brought about by cross breeding (hybridisation) with dogs, research shows.

A UNSW study published today in Evolutionary Biology has found the dingo skull shape remains unchanged by cross breeding, overturning long-held fears that cross breeding may result in the loss of the predator's ecological niche.

"We know that cross breeding has an effect on the dingo gene pool but what we didn't know until now is whether cross breeding changes the dingo skull," said study lead author Dr William Parr, Postdoctoral Research Fellow at UNSW Medicine's Surgical and Orthopaedic Research Laboratory.

"This study has shown us that the dingo skull shape, which in part determines feeding ability, is more dominant than dog skull shapes," Dr Parr said...

Edited by Thistle the dog
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Khawla Zwida and Michelle Anne Kutzle,

"Non- Reproductive Long - Term Health Complications of Gonad Removal in Dogs as Well as Possible Causal Relationships with Post - Gonadectomy Elevated Luteinizing Hormone (LH) Concentrations”. Journal of Etiology and Animal Health (March 2016)

Link to article

On mobile, too hard to quote abstract. It's in the link.

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  • 1 month later...

Putting the full study here:

A genetic assessment of the English bulldog

Niels C. PedersenEmail author, Ashley S. Pooch and Hongwei Liu

Canine Genetics and Epidemiology 20163:6 DOI: 10.1186/s40575-016-0036-y © The Author(s). 2016


This study examines genetic diversity among 102 registered English Bulldogs used for breeding based on maternal and paternal haplotypes, allele frequencies in 33 highly polymorphic short tandem repeat (STR) loci on 25 chromosomes, STR-linked dog leukocyte antigen (DLA) class I and II haplotypes, and the number and size of genome-wide runs of homozygosity (ROH) determined from high density SNP arrays. The objective was to assess whether the breed retains enough genetic diversity to correct the genotypic and phenotypic abnormalities associated with poor health, to allow for the elimination of deleterious recessive mutations, or to make further phenotypic changes in body structure or coat. An additional 37 English bulldogs presented to the UC Davis Veterinary Clinical Services for health problems were also genetically compared with the 102 registered dogs based on the perception that sickly English bulldogs are products of commercial breeders or puppy-mills and genetically different and inferior.


Four paternal haplotypes, with one occurring in 93 % of dogs, were identified using six Y-short tandem repeat (STR) markers. Three major and two minor matrilines were identified by mitochondrial D-loop sequencing. Heterozygosity was determined from allele frequencies at genomic loci; the average number of alleles per locus was 6.45, with only 2.7 accounting for a majority of the diversity. However, observed and expected heterozygosity values were nearly identical, indicating that the population as a whole was in Hardy-Weinberg equilibrium (HWE). However, internal relatedness (IR) and adjusted IR (IRVD) values demonstrated that a number of individuals were the offspring of parents that were either more inbred or outbred than the population as a whole. The diversity of DLA class I and II haplotypes was low, with only 11 identified DLA class I and nine class II haplotypes. Forty one percent of the breed shared a single DLA class I and 62 % a single class II haplotype. Nineteen percent of the dogs were homozygous for the dominant DLA class I haplotype and 42 % for the dominant DLA class II haplotype. The extensive loss of genetic diversity is most likely the result of a small founder population and artificial genetic bottlenecks occurring in the past. The prominent phenotypic changes characteristic of the breed have also resulted in numerous large runs of homozygosity (ROH) throughout the genome compared to Standard Poodles, which were phenotypically more similar to indigenous-type dogs.


English bulldogs have very low genetic diversity resulting from a small founder population and artificial genetic bottlenecks. Although some phenotypic and genotypic diversity still exists within the breed, whether it is sufficient to use reverse selection to improve health, select against simple recessive deleterious traits, and/or to accommodate further genotypic/phenotypic manipulations without further decreasing existing genetic diversity is questionable.

Plain English Summary

The English bulldog is one of the most popular breeds in the world because of its child-like appearance and demeanor. The alterations in body type and behavior needed to create the breed have required physical changes well beyond its village dog ancestors. These changes have occurred over hundreds of years but have become particularly rapid over the last decades. Unfortunately, popularity does not equate to health and there have been increasing pressures on breeders to moderate the extreme physical changes that now affect the breed and its health. Improving health through genetic manipulations presumes that enough diversity still exists to improve the breed from within, and if not, to add diversity by outcrossing to other breeds. The present study was an assessment of genetic diversity that still exists in a representative number of individual English bulldogs using DNA rather than pedigrees. The results confirm that the breed has lost considerable genetic diversity through such things as small founder population and artificial genetic bottlenecks resulting from highly focused selection for specific desired physical traits. This is manifested by a narrowing of allele diversity in many parts of the genome, and the creation of numerous large regions of the genome that are essentially identical within the breed, which are significantly different from other dogs. Loss of genetic diversity is also pronounced in the region of the genome that contains many of the genes that regulate normal immune responses. The loss of genetic diversity and extreme changes in various regions of the genome will make it very difficult to improve breed health from within the existing gene pool. Loss of present genetic diversity is further threatened by rapid integration of new coat color mutations, increased wrinkling of the coat, and attempts to create a more compact body type. Contrary to current beliefs, brachycephaly and the resulting breathing problems in the breed are the result of complex changes in head structure, and cannot be corrected by merely lengthening the face. Furthermore, other issues in English bulldogs need to be addressed, including many serious health problems that are not associated with brachycephaly, but are intrinsic to inbreeding.

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  • 4 months later...

Don't know if this has been posted yet but it's a fascinating study. It's really exciting that we are finally starting to ask the right questions when it comes to learning about animal cognition.


A comparison between wolves, Canis lupus, and dogs, Canis familiaris, in showing behaviour towards humans.

Heberlein MT, et al. Anim Behav. 2016.

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Minimizing fear and anxiety in working dogs: A review


The causes of fear and anxiety in working dogs are multifactorial and may include inherited characteristics that differ between individuals (e.g. Goddard and Beilharz, 1982; 1984a,b ), influences of the environment ( Lefebvre et al., 2007 ), and learned experiences during particular sensitive periods ( Appleby et al., 2002 ) and throughout life. Fear-related behavior compromises performance, leads to significant numbers of dogs failing to complete training (e.g., Murphy, 1995; Batt et al., 2008 ), early withdrawals from working roles ( Caron-Lormier et al., 2016 ), and can jeopardize dog and handler safety. Hence, amelioration of fear and anxiety is critical to maintain dogs in working roles and to ensure their well-being. Although current methods of selection and training are seemingly effective at producing many dogs which work in a remarkable array of environments, some dogs do not make the grade, and longevity of service is not always maximized. Programs should strive for optimal efficiency and they need to continually analyze the value of each component of their program, seek evidence for its value and explore potential evidence-based improvements. Here we discuss scientific evidence for methods and strategies which may be of value in reducing the risk of fear behaviors developing in the working dog population and suggest potentially valuable techniques and future research to explore the benefit of these approaches. The importance of environmental influences, learning opportunities, and effects of underlying temperament on the outward expression of fear and anxiety should not be underestimated. Identification of characteristics which predict resilience to stress are valuable, both to enable careful breeding for these traits and to develop predictive tests for puppies and procured animals. It is vitally important to rear animals in optimal environments and introduce them to a range of stimuli in a positive, controlled, and gradual way, as these can all help minimize the number of dogs which develop work-inhibiting fears. Future research should explore innovative methods to best measure the relative resilience of dogs to stressful events. This could include developing optimal exposure protocols to minimize the development of fear and anxiety, and exploring the influence of social learning and the most effective elements of stimulus presentation.
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Nature and nurture—How different conditions affect the behavior of dogs


Temperament tests for working dogs can provide substantial information about a particular dog's behavioral phenotype. When a larger proportion of the population is tested, the test results can also provide information about the effects of different environmental conditions on the phenotype because if the population is large, the social and physical environments to which the dogs are exposed differ.

This means that we need to include in our evaluations the perspective that uses information about the environment in relation to the individual dog's level of development.

There is substantial evidence that basic temperament traits in dogs are moderately heritable.

There is also evidence that postweaning conditions have a huge effect on development, and this effect is often not assayed.

Selective breeding for desired traits in combination with optimal environmental conditions, adapted to the individual dog's level of maturation, is a key point when producing outstanding working dogs.

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Not sure if these have been shared before but these are a couple of facebook pages which often share interesting info and research.



Thank you! I didn't know about that second link.

Here's another facebook research resource: https://www.facebook.com/iaabcorg/

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  • 5 weeks later...

How a dog's diet shapes its gut microbiome


Summary: Studies of the gut microbiome have gone to the dogs -- and pets around the world could benefit as a result. In a new paper, researchers report that the ratio of proteins and carbohydrates in a canine's daily diet have a significant influence on the balance of microbes in its gut. Researchers observed that dogs fed a high-protein, low-carbohydrate diet had enriched microbial gene networks associated with weight loss in humans.



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I'm really enjoying reading all of the articles posted in this thread. Its fascinating to see how studies tell you to work with your pet. Since every dog is a little different not all tricks have been successful but they definitely start you on the right tracks and develop good habits as an owner.


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“Reactive Dogs and Exercise: Can modifying the daily exercise regime improve behaviour?”




Simple summary of the key findings by "Wheres your Sit" a dog training blog




The dogs in the study were sent on a “doggie” vacation where exercise was significantly reduced. The owners of the dogs were nervous of this at first given that many of the dogs that participated were also described as hyper dogs that required great amounts of exercise.

What was found instead was that with reduced physical exercise (off leash running, long walks, playtime with other dogs, ball and disc play, etc.) and increased soothing touch and mental games the dogs improved significantly in only 6 days! The study goes on to cite work that includes giving dogs a drastic change for a month to see truly improved results in reactivity.

This is important for owners of dogs with arousal and reactivity issues on many fronts as simply tiring the dog out physically isn’t going to get you the results you want.

Here’s a great list of activities you can do with your own dog when reducing high impact or lengthy activity in order to decrease stress in your dog:

  • Sniff games inside and outside
  • Tracking (this is a great sport that Where’s Your Sit offers classes for and is suitable for reactive dogs as we don’t expose the dogs to one another)
  • Trick training
  • Shaping games with a clicker (can also result in your dog knowing even more tricks!)
  • Soothing massage and touch
  • Short on leash walks well away from other dogs, recommended 15-20 min per day and allowing your dog to do a significant amount of sniffing on these outings
  • Interactive feeding and puzzle games

Reactivity and overall stress and anxiety are closely linked. It’s important that your dog is allowed to calm down and “reset” after an incident where they reacted or were startled or injured by another dog.

These same calming activities can also be used with over excited or hyper dogs that don’t struggle with reactivity.



Edited by Thistle the dog
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  • 7 months later...
On 5/2/2011 at 12:03 AM, Jed said:

I understood that this forum was solely for listing links to various interestng dog related research, not for discussion/argument.



Here is a link to articles written by Catherine O'Driscoll DVM, based on research conducted at Purdue. Purdue is a large university, where a lot of research is conducted, by people who regularly publish, such as Dr Glickman DVM et al. I suggest you read Dr O'Driscoll's article and the supporting research.


I can assure you that the evidence is not anecdotal, and it is being taken seriously by everyone, including vets world wide, who base their statements on research and who are open minded.

If you believe it is anecdotal, you either need new sources of information, or you need to do some research.

Numerous dogs die of this in Australia annually, yet their vets assure them that the dog died because of hereditary problems leading to a poor immune system, or "just bad luck". This information has been available for years, yet the nay sayers continue to rebuff it.

And that is detrimental to all dogs.

Agree - my 8 week old pup died within days of the first vaccination of C3


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