Between the time dogs and people first fought over a bone at a kill and the time they shared a burger at a drive-thru, humans somehow molded dogs into the most varied and specialized species on earth. They did all this without the concepts of evolution, genes or DNA.

Then came Darwin, Mendel, and Watson and Crick. The last century has seen more changes in dog breeding than the past 10 centuries combined. In the 20th century, researchers such as Stockard, Warner and Humphries, and Scott and Fuller undertook hundreds, if not thousands, of experimental crosses. But by the last quarter of the 20th century, large-scale dog genetic projects were gone, largely because dog-breeding studies took too much time, space and money.

A few researchers maintained small genetic projects. Gregory Acland and Gustavo Aguirre were searching for answers to progressive retinal atrophy (PRA) inheritance in dogs. Their pedigree analyses and crosses between breeds showed that several types of PRA existed, most of which were recessively inherited. Breeders clamored for some way to identify carriers, but without information about the dog genome, finding the gene and devising a DNA test was only a dream.

That dream started to materialize when Jasper Rind, a yeast geneticist, became interested in the inheritance of canine behaviors such as herding and swimming and ran into the same roadblock as Acland and Aguirre. But Rind was acquainted with the process of building genetic marker maps, so he assigned his post doc, Elaine Ostrander, to the task of building one for the dog.

Pressing forward

The project began slowly but got a boost in 1996 when Ostrander joined forces with Acland and Aguirre, giving her access to their samples and pedigrees. Their combined efforts produced the first rough map of the dog genome, with 150 markers. It didn’t pinpoint the gene for PRA, but it narrowed down its location to one chromosome.

Funding was still scarce because mice, not dogs, were the accepted animal model for human hereditary disease. That changed in 1998, when researchers discovered the mutation causing narcolepsy in Dobermans. Human narcolepsy researchers used the information from the narcoleptic dogs to better understand the process in people, something mouse research hadn’t provided. If dog genetic research was applicable in this case, why wouldn’t it be applicable in others?

In fact, dogs make ideal candidates for genetic research that can help people. They share many of the same diseases and environmental risk factors as humans, and they have highly distinctive breeds with distinct disease predispositions. Some breeds have been essentially inbred for hundreds of generations, and most dogs come with generations of known pedigrees. These reasons, among others, convinced the National Institute of Health to provide the funding needed to create a complete genome map of the dog.

It was completed ahead of schedule, and as technologies improved, maps based on other dogs were added in a fraction of the time the first map took. By comparing sequences from several dog breeds, researchers have identified 2.5 million places on the genome where changes in a single nucleotide frequency often occur, accounting for the variation we see in dogs. These single nucleotide polymorphisms (SNPs) may soon be available in a public database called “CANMAP.”

Because dogs are more inbred than people, finding individual genes responsible for a disorder is comparatively easy. Generations of inbreeding result in sections consisting of millions of bases of identical DNA within a breed, as compared to only tens of thousands in people. And because breeds descend from only a few founders, a hereditary disorder found in a breed tends to arise from the same mutation in every affected member of that breed. This differs from the case in people, or even mixed breeds, in which it’s possible for diseases that look the same to be caused by different mutations.

By comparing genetic maps from different breeds, researchers estimate how closely breeds are related to one another. This makes it easier to home in on mutations for diseases shared by related breeds because such mutations probably come from the same founding stock. When a similar-appearing disorder occurs in a distantly related breed, it’s more likely to arise from separate mutations. Collie Eye Anomaly, for example, occurs in several related herding breeds. This made it easier for researchers to narrow down the candidate genes to only a few that were shared by four different related breeds with the disorder.

Human-canine DNA

Which brings us back to the gene for PRA. At first glance, dogs with PRA seem to have the same disorder. But Acland and Aguirre’s early research had shown that different breeds get different types of PRA. The gene for the most widespread form of PRA, progressive rod-cone degeneration (prcd), was among the first genetic mutations located in the dog. Since then, DNA tests have been developed for many canine hereditary diseases, including other types of PRA, von Willebrand’s disease, cystinuria, and others. Of course, some tests don’t quite make the list of Nobel Prize eligibility, but they’re still useful – and popular. In fact, some ongoing research is now aimed at finding genes associated with normal conformation differences such as skull and limb length and hair types.

In a few recent studies, the use of SNPs allowed the researchers to pinpoint target genes using just a handful of dogs. In one case, fewer than two dozen dogs were needed to track down the mutation responsible for white coat color in Boxers. It turns out that white Boxers really are different from your average white dog. The white is caused by the same mutation found in people with Waardenburg syndrome, which causes pigment abnormalities and hearing loss. The ability to use just a few dogs to find mutations opens the door for mapping less widespread conditions.

Success is often measured by funding. The AKC Canine Health Foundation and the Morris Animal Foundation both continue to fund genetic studies. Both organizations recently contributed to the $2.2 million needed for startup funds for the Pfizer Canine Comparative Oncology and Genomics Consortium (Pfizer contributed more than $1 million), which is gearing up to collect tissues and fluids from 3,000 dogs over the next three years. And thanks to a grant for $16 million, European researchers have recently organized LUPA, a consortium of 20 universities. They plan to gather DNA samples and health histories from 8,000 dogs, using the data to look for genes for 18 diseases.

Grooming can help keep a dog healthy. Removing mats and tangled fur is a good way to prevent sores and other skin irritations from developing. Fleas, ticks and other parasites are more readily uncovered, and it is easier to spot lumps and tender spots when a dog is groomed. But some grooming products have unpleasant side effects on some sensitive dogs, Despite its benefits, grooming can cause problems, especially if a dog is allergic to ingredients in the products used.

Skin Irritants

Symptoms of skin problems due to a shampoo allergy include excessive scratching or licking, scabs, hot spots, scaly patches and flaky skin. Like people, dogs’ skin carries natural oils that shampoos can strip. Discontinuation of the offending products will usually stop the allergic reaction. Be certain to use products meant for dogs, rather than human shampoos, as dogs’ skin has a much higher pH level than humans’. Hypoallergenic shampoos are available from groomers and pet supply stores. In addition, veterinarians have prescription shampoos for dogs with severe allergies.

Cancer Threat

Some dog shampoos have strong ingredients including toluene, butyl acetate and ethyl acetate. For example, butyl acetate is a chemical solvent that serves as a foaming agent and is also used in upholstery shampoo and nail polish. These ingredients are thought to contribute to organ problems and an increased cancer rate in laboratory animals and humans. Read the label to find shampoos with less caustic ingredients. Hypoallergenic shampoos and natural-formula shampoos can be found at pet supply stores and from groomers.

Clipping Too Close

A dog’s skin can become irritated if it is clipped too close or if the clippers get too hot and burn the skin. Scabs can appear and the skin can become blotchy, usually clearing up on its own within a week. The skin can be treated with antibiotics if the irritation is severe and persistent.

Health Problems for Dog Groomers

On that proverbial other side of the coin, people who groom dogs can face health problems. These typically stem from daily exposure to chemicals, disinfectants and pesticides in some grooming products and manifest themselves as skin allergies and other maladies. In addition, some dog parasites can be transmitted to groomers. Treatment depends on the exact cause of the problem and often involves changing the dog shampoo and other grooming products used.

I began competing in agility eight years ago with my Chihuahua, Ruben. I was soon hooked, and it wasn’t long before my weekends were planned around whichever agility trial was taking place. I retired Ruben at 7 years old, but around that time my Border Collie, Torque, decided disc-dog competition was his niche. For a period of time, that was the dog sport that occupied my weekends.

When my Pharaoh Hound, Logan, joined the family, I had the opportunity to try dog sports I had not yet experienced. It started out innocently enough with conformation events, but while working on conformation, I decided to try Logan in lure coursing. Logan turned out to be a natural, and has been awarded multiple Best-in-Field titles.

Agility, disc-dog competition, conformation and lure coursing are offered year-round, rain or shine. About a month ago, I experienced a problem I had never encountered. For the first time in almost a decade of competing in dog sports, one of my dogs experienced heatstroke. At a lure-coursing event, Logan became overheated. He’s completely recovered now, with no apparent long-term negative effects, but it was an experience that demonstrated firsthand how quickly this potentially life-threatening condition can arise.

What is heatstroke?

In simple terms, heatstroke occurs when a dog loses its natural ability to regulate its body temperature. Dogs don’t sweat all over their bodies the way humans do. Canine body temperature is primarily regulated through respiration (i.e., panting). If a dog’s respiratory tract cannot evacuate heat quickly enough, heatstroke can occur.

To know whether or not your dog is suffering from heatstroke (as opposed to merely heat exposure), it’s important to know the signs of heatstroke.

A dog’s normal resting temperature is about 100.5 to 102.5 degrees Fahrenheit. Once a dog’s temperature rises above 105 degrees, physiological changes start to take place, and the dog begins to experience the effects of heatstroke. At 106 to 108 degrees, the dog begins to suffer irreversible damage to the kidneys, liver, gastrointestinal tract, heart and brain.

If a dog is experiencing heatstroke, you may observe excessive panting; hyperventilation; increased salivation; dry gums that become pale, grayish and tacky; rapid or erratic pulse; weakness; confusion; inattention; vomiting; diarrhea; and possible rectal bleeding. If the dog continues to overheat, breathing efforts become slowed or absent, and finally, seizures or coma can occur.

The amount of damage a dog sustains when stricken with heatstroke depends on the magnitude and duration of the exposure. The longer and more severe the exposure, the worse the damage will be.

What to do:

Pay attention to your dog. Recognizing the symptoms of heatstroke and responding quickly is essential for the best possible outcome.

Get into the shade. If you think your dog is suffering from heatstroke, move it into a shaded area and out of direct sunlight. Apply cool water to the inner thighs and stomach of the dog, where there’s a higher concentration of relatively superficial, large blood vessels. Apply cool water to the foot pads, as well.

Use running water. A faucet or hose is the best way to wet down your dog’s body. Never submerge your dog in water, such as in a pool or tub – this could cool the dog too rapidly, leading to further complications, including cardiac arrest and bloating.

Use cool – not cold – water. Many people make the mistake of using cold water or ice to cool the dog. When faced with a dog suffering from heatstroke, remember that the goal is to cool the dog. Using ice or extremely cold water is actually counterproductive to this process because ice and cold water cause the blood vessels to constrict, which slows blood flow, thus slowing the cooling process.

Don’t cover the dog. One of the keys to successfully cooling your dog is ensuring the water being placed on the dog can evaporate. Never cover an overheated dog with a wet towel or blanket. This inhibits evaporation and creates a sauna effect around your dog’s body. Likewise, don’t wet the dog down and put it into an enclosed area, such as a kennel. Any air flow during the cooling process is helpful in reducing the dog’s body temperature. Sitting with the wet dog in a running car with the air conditioner blowing is an ideal cooling situation.

Keep the dog moving. It’s important to try to encourage your dog to stand or walk slowly as it cools down. This is because the circulating blood tends to pool in certain areas if the dog is lying down, thus preventing the cooled blood from circulating back to the core.

Allow the dog to drink small amounts of water. Cooling the dog is the first priority. Hydration is the next. Don’t allow the dog to gulp water. Instead, offer small amounts of water that’s cool, but not cold. If the dog drinks too much water too rapidly, it could lead to vomiting or bloat.

Avoid giving human performance drinks. Performance beverages designed for humans are not recommended because they are not formulated with the canine’s physiology in mind. If you can’t get an overheated dog to drink water, try offering chicken- or beef-based broths.