CCD in Dogs – Chromosome 34 Points to People with OCD
CCD in dogs and its findings may soon benefit humans who have been diagnosed with OCD. According to scientists, no previous study in humans or dogs has dealt with discoveries that can drive the level of severity of OCD in humans or CCD in dogs. When a rough sketch of the canine genome was completed in September 2003, it was discovered there was a strong similarity between dogs and humans.
According to the 2003 “National Geographic“, “Dogs suffer from more than 350 genetic disorders, many of which resembled human conditions,” said Ewen Kirkness, a molecular biologist at the Institute for Genomic Research in Rockville, Maryland, who led the research. “The genes responsible for these are probably constant to humans and dogs.”
In the Tuft research, whole genome sequencing of 70 Doberman Pinschers was researched for inherited factors that aggravated CCD in dogs. Of the three chromosomes that were found, two loci on chromosomes were correlated with severe CCD while a third locus showed evidence of an association.
Chromosome 34 in dogs
It was discovered that Chromosome 34 in the Doberman study contains three serotonin receptor genes. Another recent study has found four genes, but according to a PR from the Tufts University where the study was done, the “newly identified genomic causes of severe compulsive behavior in dogs” is furthering a deeper understanding of human OCD.
Located in Medford, Mass., the research was led by veterinarian investigators and investigators associated with human medicine. They identified canine genetic pathways in Doberman Pinschers. The importance of this discovery is that it may lead to better therapies for human OCD, obsessive-compulsive disorder, along with better medical and psychological treatments.
“Canine compulsive disorder shares behavioral hallmarks, pharmacological responsiveness, and brain structural homology with human OCD, and thus is expected to be an important animal model,” says neurologist Edward Ginns, MD, Ph.D., professor of psychiatry, neurology, pediatrics and clinical pathology, and director, program in medical genetics at the University of Massachusetts Medical School and a co-author on the Tufts CCD in dog study.
An article describing the discovery appears in the February 29 post of the “International Journal of Applied Research in Veterinary Medicine.”
“Dogs naturally suffer complex diseases, including mental disorders that are similar to those in humans. Among those is canine compulsive disorder (CCD), the counterpart to human obsessive compulsive disorder (OCD).” says the study’s first and corresponding author Nicholas Dodman, BVMS, DACVA, DACVB, professor in clinical sciences and section head and program director of animal behavior at Cummings School of Veterinary Medicine at Tufts University.
CCD in dogs and human disorders
One of the earliest discoveries on CCD in dogs, also known as obsessive compulsive disorder, was by principal investigator Dr. Judith L. Rapoport. Also a well-known child psychologist, she has written over 300 scientific research papers and over 200 journal articles. Dr. Rapoport is Chief of the Child Psychology Branch at the National Institute of Mental Health (NIMH) in Bethesda, Maryland, specializing in four major fields associated with children that would eventually lead her to CCD in dogs.
- Attention Deficit Hyperactivity Disorder
- Childhood Onset Schizophrenia
- Child Psychology
- Obsessive Compulsive Disorder
She also studies clinical phenomenology, neurobiology, and the treatment of Childhood Onset Schizophrenia for children at her NIMH research group. Dr. Rapoport best describes OCD, “Obsessive compulsive disorder is a disorder in which thoughts and doubts and personal rituals run wild” in her personal interview for Medscape.
Human – Canine similarities with diseases and disorders
Two years ago, BBC published an article showing human diseases that show canine similarity.
- Arthritis and Joint Pain
- Cushings disease
- Down Syndrome
- Heart Disease
- Hip dysplasia
- Hydrocephalus (water on the brain)
- Kidney disease
- Liver Disease
- Muscular dystrophy
- OCD, Obsessive Compulsive Disorder and CCD in dogs (you’re reading it!)
- Pulmonary Hypertension
- Retinal degeneration
- Situational anxiety
- Substance abuse
According to the 2014 BBC article, “these shared diseases mean that dogs are emerging as one of the most important animal models of human hereditary diseases, advancing our understanding and paving the way for new therapies.”
Dog breeds associated with specific diseases and mental disorders
Occasionally, we see our dog do something sweet and humanlike, like gently pat your shoulder to get a bit’ of attention or turn their back on you when they don’t like what you said. It’s then we feel a close bond with them. And the more they do these cute little things, the more we feel a human connection.
Pets are used for research for these same little human quirks, as they are in the same environment as their owners. “… the environment can have an effect on how genes are expressed, and so any gene-environment interactions that cause human disease also affect our canine friends.” BBC
However, studies show that the CCD is less complex than human OCD. When seen by veterinarians, about 2% to 5% of dogs are diagnosed with CCD. The number one treatment is medication, with memantine playing a vital role.
Listed are a few breeds of dogs that play a certain role with the most common human OCD and other diseases and disorders. Studying dogs who shared human disorders and diseases, PBS had a show on called “Dogs That Changed the World.”
- Addison’s Disease, an autoimmune disorder, affects the hormone-producing adrenal glands. It is seen in Bearded Collie, Portuguese Water Dog, and Standard Poodles
- Allergies of the skin, or atopic dermatitis, are the most susceptible in Dalmatians, Vizslas, and several terriers, such as the Boston Terrier, Bull Terrier, and the West Highland White Terrier
- Autoimmune disorders are commonly seen in Basset hounds, Cardigan Welsh Corgis, and Dachshunds
- Blood disorders occur commonly in Basset Hounds. It is an inherited abnormality the effects the ability of the platelets in the blood to clump together after an injury.
- Breast Cancer occurs in Golden Retrievers
- Diabetes mellitus is an autoimmune disorder that affects the body’s response to sugar. It is frequent in Samoyeds and Australian Terriers
- Doberman Pinschers, Bull Terriers, and German Shepherds are very susceptible to CCD
- Obesity is the number one problem in humans and most dogs, and the cause of many diseases
- Staphylococcus and other bacteria, which cause frequent skin infections, is most seen in Chinese Shar-Pei
- von Willebrand’s disease occurs most commonly in Doberman Pinschers
- Yorkshire terrier dogs faint when they’re stressed out.
Largest genetic study of 4,200 dogs
… genetics in dogs is far simpler than in humans, and since dogs are diagnosed with many of the same diseases as humans, studying dog genetics is a “useful and underused way to understand genetic diseases from a human perspective,” said Adam Boyko, assistant professor of biomedical sciences at Cornell’s College of Veterinary Medicine and the paper’s senior author. Jessica Hayward, a postdoctoral research associate in Boyko’s lab, and Marta Castelhano, director of the Cornell Veterinary Biobank, are co-lead authors of the paper.
Cornell University and its researchers have completed the largest genetic study of dogs to date. It comprises the genetic analysis of 4,200 dogs. Investigating 180,000 genetic markers, the investigators helped link inherited diseases with the responsible gene. The DNA sequences are shown with a physical location on each dog’s chromosome.
The study was published on January 22, 2017, journal of “Nature Communications.” The mapped canine genes have helped us to better understand human genetic diseases. According to the researchers at Cornell, “By identifying important genes and proteins in dogs for diseases and traits, researchers may then test those homologous genes in humans.”
Terms associated with canine genomes:
- Chromosomes are the structures that contain the genetic material. (a) They are complexes of DNA and proteins.
- The genome comprises all the genetic material that an organism possesses. (a) In bacteria, it is typically a single circular chromosome. (b) In eukaryotes is any organism whose cells have a nucleus and other organelles enclosed within membranes. (a) It refers to one complete set of nuclear chromosomes.
- Eukaryotes possess a mitochondrial genome.
- Plants have a chloroplast genome
- OCD is obsessive-compulsive disorder in humans, while its counterpart, CCD in dogs, is canine compulsive disorder