It was first discovered that diabetics lacked the hormone insulin through studies in dogs - the results of which earned scientists the Nobel Prize in the 1920s. Both cats and dogs were important in the development of the heart-lung machine which made open-heart surgery possible. Later, dogs were the first animals used in the attempt to conquer the rejection of transplanted organs. Once again, a Nobel Prize for medicine (1990) was awarded to researchers who studied the immunological basis of organ rejection using dogs. Dogs are still important in heart research and in the safety testing of new medicines. [5,782]
See also our video of dogs.
In November 2012, researchers published the first double-blinded, randomized, controlled study into using cell transplants to treat spinal cord injury. The trial was conducted on pet dogs, mostly dachshunds, which had had spinal injuries through accidental injury. The researchers took a sample of olfactory ensheathing cells (OECs) from the noses of each of the dogs. These cells were known to promote nerve growth, as the nose is the only part of the body where nerve cells continue to grow in adulthood. This study garnered much media attention with videos of the dogs’ remarkable improvement.
In 1889 Joseph von Mering and Oskar Minkowski showed that removing the pancreas from a dog produced diabetes. This was the first demonstration of an anti-diabetic factor, later discovered to be insulin, produced by the pancreas and enabling the body to regulate sugars in the blood. In 1909 Forschbach showed that crude insulin extracts could reduce blood sugar levels by 90% in these dogs. Unfortunately, impurities in the extract meant this preparation of insulin had toxic effects. When James Collip and Frederick Banting developed a new technique for purifying insulin from cow pancreas, it was tested successfully in dogs and then in patients in 1922 with dramatic results, leading to Banting being awarded a Nobel Prize the next year.
Ivan Pavlov’s experiments on the digestive systems of dogs provided the first detailed observations of how the digestive system worked. This was made possible through his surgical techniques that allowed him to observe the digestive processes while the animals were able to behave normally. Among his findings, Pavlov described the physiology of the salivary glands, the stomach and the intestines in detail. He showed that the digestive tract is influenced by the central nervous system in a complex manner, and that psychological process can influence the nature of the fluids secreted into the digestive tract. For this work, Pavlov was awarded a Nobel Prize in 1904.
Duchenne muscular dystrophy is the most common form muscular dystrophy, affecting 1 in 3500 boys born. The only animal model that reproduces the human pathology and biochemical mechanisms is the Golden Retriever dog. Researchers took stem cells taken from these dogs and corrected the mutated gene before injecting back into the dogs’ muscle tissue. There the stem cells formed muscle fibre and restored some level of function to the muscles.
Ventricular fibrillation is a common cause of cardiac arrest where the muscles of the heart are uncoordinated and fail to pump blood. This was first described in dogs in the 1840s when scientists discovered it could be induced by ligating the coronary artery or applying an electric current. In 1899, Jean Louis Prevost and Frederic Batelli in Geneva demonstrated that electrical currents could also be used to restore normal rhythm to a dog’s heart, thereby inventing the first electrical defibrillator.
In 1880, Louis Pasteur developed an anti-rabies vaccine for dogs, by using dogs in his research. Pasteur used injections of infected nervous tissue into the dogs’ brains to reproducibly induce rabies in the dogs. By drying nerve tissue of infected rabbits, Pasteur produced a weakened sample of the virus. When this was given over a 2 week period with stronger doses each time, he was able to immunise the dogs so that they became resistant to the virus.
In 1950, WG Bigelow studied the effects of hypothermia on the energy use of dogs. He found that they could be cooled to 20C with no ill effects and their oxygen consumption and heart rate reduced by 85%. This was viewed as a means to allow the heart to be isolated during surgery, while minimising the damage to the body. At lower temperatures the heart would undergo ventricular fibrillation and stop completely. Bigelow discovered that the dogs’ heart could be restarted with an electrical charge, leading to the design of the pacemaker.
In multiple studies, dogs have been “intriguingly accurate” at detecting certain cancers by smelling breath or urine samples. In recent research, published in 2011 in the journal Gut showed a Labrador retriever trained in cancer scent detection correctly identified 91% of breath samples and 97% of stool samples from patients with colon cancer.
Can dogs predict drops in blood sugar? In 2008, Deborah Wells, PhD, a psychologist at Queens University in Belfast, Northern Island, reported on type 1 diabetes patients who said their animals often alerted them to low blood sugar before they noticed their own symptoms. Wells is now studying whether there is scientific evidence to support the phenomenon. Lawrence Myers, DVM, PhD, an expert in canine scent detection at Auburn University College of Veterinary Medicine, says it’s “plausible” that dogs would be able to detect the odour associated with low blood sugar.
How about seizures? Doctors can’t explain it, but some patients with epilepsy report that their dogs are able to tell them when a seizure is coming. Jennifer Arnold, founder of Canine Assistants in Georgia, tells service-dog recipients there’s no way to train the animals to predict seizures -- only to respond once they occur. But she says about nine out of 10 of the service dogs her organization has placed develop the ability on their own within a year of placement.
Nearly one million lampposts in Derbyshire are to be checked by the council to ensure dog urine has not corroded the metal. A report found that years of exposure to the highly acidic urine from dogs can cause the base of the posts to crumple away.