Summer Heat Study

I am finally getting around to putting together the test results and data from the Summer Heat Study, and I'm posting the results in this entry.

If you are new to my blog, or have not been here in a long time, you may want to read the Study's frequently asked questions and parameters to see how it was set up and what I'm hoping to gain by publicizing this information. If you'd just like to learn more about how to keep your dog safe in summer, please click here for my article on Summer Safety for Dogs.



Base Line Temperature - The Foundation

The most important part of my study, before I ever got to testing different activity levels and products that help keep dogs cool, was to establish my dog's Base Line Temperature. This is important in this study because like people, some dogs run "hotter" or "colder" than others. If you plan to monitor your dog's temperature with exercise and in the summer heat to keep them safe, I would recommend that you establish each individual dog's Base Line Temperature before you start any monitoring.

Establishing BLT is done over the course of one week, by taking the dog's rectal temperature when your dog is first getting up in the morning. My dog sleeps in her crate at night, so I took her temperature immediately after calling her out of the crate in the morning.

You will want to write down the temperatures, add them all up, and then divide them by the number of days to get a Median BLT reading. In my case, Abby's median temperature over the course of a week was 99.5 degrees in the morning. Temperatures are normally slightly higher in the evening / at night.

Temperatures between 100 and 102.5 degrees are considered "normal" body temperatures for dogs.



What a Difference Exercise Makes

Probably the most eye-opening part of my study was the effect of exercise on my dog.

There are many factors that determine how well a dog will do in the heat: the dog's breed, age, weight, fitness level, and medical issues. On a sliding scale, Abby would be considered to be a dog that has few "risk factors" and that would adapt well to the summer heat. She is a German Shepherd, which is a long-muzzled breed with a double coat that helps to trap the air and regulate body temperature. She is a young adult at just over four years old. She is at a healthy weight for her size and body type - just about 60lbs - and in good physical condition. She has no known medical issues.

However, even without any of those additional risk factors, Abby's body temperature went above 103.5 degrees with just one one-mile walk on a hot and humid day!

In order to put this temperature into perspective, let's back up a little and talk about heatstroke. Generally, veterinarians consider dogs with body temperatures between 104 and 106 degrees to be suffering from "moderate heatstroke". Some of the signs of moderate heatstroke are what most pet owners may see in their dogs when they are out in summer, walking or enjoying the park: a bright red tongue, thick and sticky saliva, and rapid panting. Even if you moved your dog to a cool area and began to cool him or her down by giving water and also pouring water on the dog, the effects of moderate heatstroke may last as long as an hour. Temperatures above 106 degrees are extremely dangerous and can kill your dog.

So when we exercise our dogs in summer, it may significantly raise their body temperature to dangerous levels, even in a very short amount of time. In Abby's case, I have seen an increase of one to three degrees from her resting temperature taken in the home prior to going outside for our exercise.

Additionally, on days that it was humid, the temperature rose significantly more than on days that the humidity was relatively low.

Humidity does play a very large role in the dog's ability to control his or her body temperature. Dogs, unlike humans, do not sweat through their skin. Their fur fills part of the function of keeping them comfortable in summer by trapping air between the layers of fur, which helps regulate their body temperature at the skin level. (This only works if you brush your dog regularly to remove loose hair, dirt, and anything else that might clog up the coat.)

In addition to that, dogs also sweat through their nose leather and their paw pads. However, most of the cooling action the dog's body naturally generates is by means of evaporation of fluid from the dog's tongue.

The way this works is that the evaporation of saliva helps to dissipate heat. The rapid exchange of cool outside air with the warm, humid air inside the lungs, helps keep a dog's temperature within its normal range. The problems start when the outside temperatures become equal or higher than the dog's body temperature, because evaporation from the tongue no longer makes a significant difference since it no longer creates cooler air. In climates with high humidity, temperatures don't even need to be higher than the dog's temperature for this process not to work, because less evaporation takes place when it is humid, and therefore, less cooling.

In my geographical area - we're in Virginia - summer days often reach the upper 90s or even temperatures in the triple digits, and we have many days with high humidity. However, as swelteringly miserable as those days are, even on a day where I might only see 86 degrees in the afternoon heat and no humidity, Abby's temperature still rose two degrees when we went for our walk or played ball outside the house - in the shade under the trees, no less.

Now imagine a dog with additional risk factors: short-muzzled breeds such as Pugs; very young or very old dogs; overweight dogs; or dogs with medical problems. It does not take long for the weather to become dangerous for them, even if it's just "your regular walk".



When and Why Cooling Products Are Needed

I know that most websites and articles about keeping our dogs safe in summer have been suggesting that you should "limit exercise" and "keep them inside where it's air conditioned".

That might be nice and feasible for naturally calm and collected dogs (as individuals or as a breed trait), but it's not really an option for those of us whose dogs need the daily exercise, such as working breeds that have high levels of energy and a need to do something: Border Collies, German Shepherds, Malinois, Jack Russel Terriers, and many herding and terrier type dogs. To not exercise a dog like that outdoors is not really a feasible option unless you have a way to keep them busy and exercised indoors, like a treadmill or indoors agility training, for example. When you don't keep a dog like this adequately exercised, many other problems can arise in the home.

Aside from dogs that need to be outside each day because of their exercise requirements, there are also a lot of dogs that need to be outside in the heat, frequently or infrequently, because of their owner's needs. What I mean by this are dogs such as service dogs that help the disabled or guide the blind, or working dogs such as Schutzhund dogs, police dogs, and search and rescue dogs, for example. Those dogs cannot just "take a break and stay indoors" because it is hot - their owners (or handlers) need to find a way to help them work in the heat.

This is where cooling products come in.



What Products are out there, anyway?

There are many companies that make many different products that help cool a dog. There are cooling bandanas and cooling vests that works by means of evaporation. There are cooling vests that work by means of rechargeable cold packs or insertable ice packs. There are freezable water bowls and an assortment of cooling beds that are soaked in cool water or used with ice-pack inserts.

All of these products work to an extent - it's how and when they're used, and how well they are used that makes a difference.

Cooling beds and freezable bowls are a great thing - if your dog is using them at home or while traveling in the car. They are not much of a help while you and your dog are outside going for a walk, playing in the yard, or if your dog is a working dog that is on the job.

At that point, cooling products that can be attached to the dog in some way need to be considered, such as bandanas, vests, wraps, and blankets. There are enough of these products on the market by so many different companies, that it's difficult to keep track of them all. Each promises to "keep your dog comfortable in the heat", though the wording differs. But how do they stack up?

The first question we need to ask is, where is cooling most effective for the dog?

Veterinarians - and human doctors, as much of this translates to human use - believe that the most effective way of cooling a dog is by means of the circulatory system. Therefore, if you cool the core of the dog - the chest area where the lungs and heart are located - as well as the areas where major arteries run -the neck, armpit, and groin - you achieve the best results in cooling.

The most prolific cooling products on the market, both for humans and dogs, are products that cool the neck and shoulders. These are filled with poly-carbonate crystals which hold large amounts of water. In order to "activate" the product, it has to be soaked in cool or cold water. The first cooling effect can be felt when the wet product is applied to the neck, as it comes in contact with the skin and lowers the outer skin temperature. Other cooling takes place by means of evaporation from the wet product.

I am not a big fan of this type of product, neither in humans nor in dogs. Because these types of product are cooling the arteries that are sending blood into the brain - the place that makes the decisions on whether the body needs to initiate or continue body procedures - they may actually tell the brain that the body is now cool, and to stop or lower any kind of cooling procedures it has in place. In other words, the brain thinks the weather's comfortable and there's no need to continue cooling the body. Which may even be dangerous.

Then there are cooling vests, wraps and blankets. The blanket products cover the back and sides of the dog, and the vest products generally cover the chest and part of the back of the dog. Some vests or wraps also cover part of the groin area - which, granted, is difficult for any product to do without impeding the dog's natural body functions, particularly in male dogs.

For my study, I tested three products.



Cooling Product Reviews

Review disclaimer: I am not a representative of any of these companies, nor do I receive any compensation to give a company a good (or bad) review. If I think a product doesn't stack up well, I'll say it just like I'll be happy to recommend a product that is good - regardless of the company or product involved.



Product Name
Cool-It Bandanna

Manufacturer
Outward Hound

Where to Buy
PetsMart stores or site

Price
$5 to $10

What it Promises
Outward Hound's Cool-It promises to be a "stylish way to keep your pets cool" and that the cooling crystals will keep your pet "cool for hours."

How it Works
The Cool-It bandana contains crystals that hold a large amount of water. You have to soak the bandana in cool water before putting it on the dog. For best results, the company advises to put it into the refrigerator after wetting and before use.

Design
The Cool-It bandana is a collar-type bandana that fits around the dog's neck. The older version, seen in the image, is solid blue, whereas the newer version (shown in the PetsMart link) is a two-tone color of blue and grey. Either version works the same and features a reflective strip for visibility and a velcro closure. The bandana comes in three sizes - small, medium, and large.

How it did in the Study
I tested the Cool-It bandana on a hot day with low humidity as well as on a hot day with high humidity. On neither day did I notice a significant difference in my dog's temperature with the bandana on as opposed to my dog not having any products on at all. At only 82 degrees outside and very low humidity, her body temperature went above 102 degrees quickly with the bandana.

What I Like
The Cool-It bandana is extremely easy to use: just soak it in water and put it on. Putting it on is as simple as putting a collar on your dog. The reflective stripe is neat as well - I always like products that help enhance visibility.

What I don't Like
The Cool-It bandana drips water for awhile before it starts evaporating any excess. In dogs that wear several collars, there is little place left for the banana - this may be an issue with dogs that have an ID collar as well as a training collar (prong, choke, etc.) or in dogs participating in Schutzhund training who often wear several collars for various purposes.

Verdict
It's a thumbs down for me. I don't think this product does what it promises and therefore it is not very useful in keeping your dog safe from the heat. I won't be using mine.



Product Name
Cool Vest (tm)

Manufacturer
Radic, Inc (Japan) via
Gramercy Distributions

Where to Buy
Lucy's Dog House

Price
$45 - $55

What It Promises
"Provides a protective layer from direct and indirect sunlight and heat. Its laminated lining keeps dogs dry! Perfect for a summer walk!"

How It Works
The Cool Vest is made from "a special fabric that absorbs and retains water" and laminated on the inside to "keep dogs dry". You have to soak the product in cool water. For maximum efficiency, the company suggest soaking it in ice water and placing it in the refrigerator for 10 to 15 minutes before use.

Design
The Cool Vest covers the back, chest, and rib cage area of the dog. The vest is designed to fit over the dog's neck, and the T-shaped flap that covers the chest goes between the dog's front legs and fastens to the top part covering the dog's back via two Velcro tabs on the sides. The neck hole is adjustable by means of a strap. Vests come in two colors, a high-visibility orange and a light blue, and various sizes from Extra Small to Large.

How it did in the Study
I tested the Cool Vest on a hot day with low humidity as well as on a hot day with high humidity. On days with low humidity, the Cool Vest helped keep my dog's body temperature lower than using no product. On days with high humidity, the effect of the vest was greatly diminished due to the lack of evaporation, and it contributed to warming my dog by serving as "another layer" covering her fur and skin.

What I Like
The Cool Vest is very easy to put on and the neck area is easy to adjust. It worked well on days with low humidity and will probably do very nicely in climates that are relatively dry. The orange color of the vest I tested was a nice visibility aid which is useful if you use this while hiking or at the park.

What I don't Like
The Cool Vest drips water for awhile before it starts evaporating any excess. Even though the product description says that "the laminated inside will keep dogs dry", I found that when the vest is soaked as the instructions say, the dog will get wet unless I towel-dry the laminated area before putting it on. It is not as adjustable as I would like - the Velcro tabs on the side are relatively short and therefore you cannot adjust too much of the chest size. I also found that because my dog is very narrow-chested, the part that goes between her front legs was uncomfortable for her with extended wear as it rubbed the sides of her legs. A narrower chest piece may be a good improvement - though I'm sure this fits fine on wider-chested dogs.

Verdict
It's a thumbs up for me. This works well in a dry climate. I would recommend this for the average dog owner to use on daily walks when it's warm out, provided you don't live in a very humid area and don't have a very narrow-chested dog.




Product Name
ChillyDog / ChillyPup

Manufacturer
Glacier Tek, Inc.

Where to Buy
Helping Udders

Price
$100 - $130

What it Promises
The ChillyDog "maintains a constant 59 degrees for up to 2.5 hours in 100 degree temperatures and recharges in minutes." It is "absolutely safe" and recharges in "10 to 15 minutes in ice water" or "30 to 45 minutes in the refrigerator". It is "adjustable to fit a wide range of working dogs."

How it Works
The ChillyDog uses rechargeable cooling packs. These cooling packs are made from food-grade fats and oils and do not create any condensation as they thaw over the period of use. The cool packs aren't freezing cold like ice packs, but keep a constant cool temperature.

Design
The ChillyDog vest covers the sides of the dog's chest, bringing the cool packs into contact with the dog's rib cage around the lungs and heart. The vest has a chest and neck strap as well as two straps that go across the back of the dog. It is easily put on by walking the dog over the vest and then pulling it up, similar to many canine car harnesses on the market. The neck straps are fully adjustable with Velcro, and the straps across the back via buckles. The cool pack compartments have Velcro closures at the top and cool packs can be exchanged without taking the vest off. D-ring hook-ups on the ChillyDog vest allow it to be used as a harness. Comes only in black. Comes only in ChillyDog (large working breeds) and ChillyPup (small working breeds) sizes.

How it did in the Study
I tested the Chilly dog on a hot day with low humidity as well as on a hot day with high humidity. It performed equally well in both tests because it does not rely on evaporation for its cooling effectiveness. The vest kept the dog's body temperature below 103 degrees on a 104 degree day with 60% humidity!

What I Like
The vest is manufactured extremely well with the same types of webbing and buckles used in military equipment. It is highly adjustable to fit dogs of various chest shapes and deepness. It was easy to put on and the cool packs were easy to insert and remove. The D-rings are an attachment point for a leash which is useful for non-pulling dogs. As there is no condensation from the cool packs, the dog stays dry.

What I don't Like
The second back strap that goes across the middle of the dog's neck slips with extended wear. I also did not like that the strap does not have Velcro or an elastic keeper to hold down the "free" end when the strap is cinched on a smaller-chested dog like Abby. I would also like to see a wider back strap for more comfort. The metal D-rings that can be used as a leash attachment need to be a thicker gauge - I'm not sure that the ones used would hold a German Shepherd or Malinois if the dog is in drive or a heavy puller.

Verdict
It's a definite thumbs-up for me. I think that this is an excellent product for people whose dogs are working dogs and need to be outside in the heat - guide and assistance dogs, police canines, and sports dogs (agility, Schutzhund, etc.).



The Bottom Line

When everything is said and done, I would sum the heat study up as follows:

First, the dangers of the summer heat and humidity and its effect on dogs are very real. Even a healthy, young, active dog can quickly be overcome by moderate heatstroke during normal daily activities.

Second, there are many dogs that need to be outside no matter what the temperatures are like, and who are good candidates for using different products to help them keep cool and comfortable. There are also many dogs who can benefit from cooling products even if they only go for a daily walk or two, or on a trip to the dog park.

Third, pet owners need to be knowledgeable about the signs of heatstroke and they need to be able to recognize and treat them in their dogs. (Incidentally, for any dog medical emergencies, the "First Aid Companion for Dogs and Cats" by Amy D. Shojai is a great book to have.)

Fourth, prevention is worth every ounce. Please keep your pets safe.