Heat Stroke

Part I : emergency treatment in the field      Part II : further treatment at the clinic

Heat stroke and overheating in dogs: treatment & prevention.

An article by Nate Baxter, DVM

© 2005

Oh the heat is here to stay (at least for the next five month) The introductory comment is by the person who reposted the article to Canine-L. This article was reposted on Canine-L, Discussion Forum for Dog Lovers on 6/8/1999.

Dearest Canine-L'er's:

I am taking the opportunity here to re-post (with permission, and permission is granted to re-post again as long as the originals are not edited and credit is given) a critical reminder about our beloved furbabies and their risk for heat stroke.

I was ... fortunate? ... that in the beginning of the first summer I had my dog I was at the vet's at a routine visit . . . a woman rushed in completely hysterical . . . her dog was incapacitated in the back seat of her car, heat-stricken..........they couldnt' save her, and I will never forget this big doggie's death-wracked gasps and gurgles and pants as she struggled to live while they were attempting to cool her down. Sorry to be so explicit but it's a deadly serious issue for our kids. She didn't make it .

The vet told me at the time to never push my dog to even *walk* his regular route if he were reluctant, to wet him down, to respect any sign of exhertion and give lots of rest, shade & fluids. Anyway, enough of me.....

This is posted with the permission of the author Nate Baxter, DVM and is a guideline and overview for dogs that overheat. While it was written for working retrievers the information applies to any dog exerting itself in warm or very humid conditions.

. . . . .The first thing that needs to be understood is that dogs and people are different enough that most of the info cannot cross lines. I do not profess to know what the appropriate procedures for people other than what I learned in first aid.

Electrolyte replacement: Dogs do not lose enough electrolytes thru exercise to make a difference, but if the dog gets truly into heat stroke the physiology changes will make them necessary. BUT oral replacement at that point is futile, they need IV and lots of it.

Cooling: The point of evaporative cooling being the most efficient is correct. However, in a muggy environment, that will not help as much, so I do cool with the coldest water I can find and will use ice depending on the situation. The best way is to run water over the dog, so there is always fresh water in contact. When you immerse a dog in a tub, the water trapped in the hair coat will get warm next to the dog, and act as an insulator against the cool water and cooling stops. If you can run water over the dog and place it in front of a fan that is the best. Misting the dog with water will only help if you are in a dry environment or in front of a fan.

Just getting the dog wet in NOT the point, you want the water to be cool itself, or to evaporate. For MOST situation all you will need to do is get the dog in a cooler environment, ie shade, or in the cab of the truck with the air conditioning on (driving around so the truck does not overheat and the AC is more efficient).

This past summer I was very concerned about my dogs getting too hot in the back of my black pickup with a black cap. Boy I wish I got another color 6 years ago

When I had one dog I just pulled the wire crate out of the car and put it in some shade and hopefully a breeze. But having 2 dogs and running from one stake to another, that was not feasible. So I built a platform to put the wire crates on, this raises the dog up in the truck box where air flow better. Then I placed a 3 speed box fan in front blowing on the dogs with a foot of space to allow better airflow. I purchased a power inverter that connects to the battery and allows the 3 speed fan to run from the truck power. It has an automatic feature that prevents it from draining the battery. When I turned that fan on medium I would find that the dogs where asleep, breathing slowly and appeared very relaxed and comfortable in a matter of 20 minutes or less, even on very hot muggy days.

Alcohol: (Rubbing Alcohol) I did not carry it but probably will next year. It is very effective at cooling due to the rapid evaporation. It should be used when other methods are not working, but do not hesitate to use it. Due to the thicker skin and rapid evaporation I do not worry about it being absorbed. Plus we recommend using rubbing alcohol, which is propylene alcohol, not ethyl, for those of you not aware. So do not try to drink it.

I purchased those cooling pads, but found that the dogs would not lay on them. I would hold them on the back of a dog that just worked to get a quick cool, but probably will not mess with them next summer. I also bought a pair of battery operated fans but found them pretty useless. Spend your money on the power inverter and get a real fan.

Watching temp: If you feel your dog is in danger of heat injury, check its temp and write it down. Keep checking the temp every 3 minutes. Don't forget to shake it down completely each time, sounds silly, but when are worried about your companion, things tend to get mixed up.

This is VERY IMPORTANT:
Once the temp STARTS to drop, STOP ALL COOLING EFFORTS. The cooling process will continue even though you have stopped. If the temp starts at 106.5, and then next time it drops to 105.8, stop cooling the dog, dry it off, and continue monitoring. You will be amazed how it continues to go down. If you do not stop until the temp is 102, the temp will drop on down to 99 or even lower. I cannot emphasis that point enough.

Limit water: When the dog is so heated that it is panting severely, only let it have a few laps of water. Water in the stomach does not cool the dog, you just need to keep the mouth wet so the panting is more effective. Do not worry about hydration until the temp has started down. A dog panting heavily taking in large amounts of water is a risk of bloat. Due to the heavy panting they will swallow air mix in a large amount of water they can bloat. Once the temp is going down and panting has slowed to more normal panting then allow water. The dog will rehydrate it self after temp is normal.

If the dog has a serious problem and even though you have gotten the temp normal, get the dog to a vet, as it can still need IV fluids and some medication. Also, a case of heat stroke can induce a case of hemorrhagic gastroenteritis (not parvo), with a ton of very bloody diarrhea and a lot of fluid and electrolyte loss. These cases need aggressive treatment.

Prevention: The best method of treatment is prevention. Learn to watch your dog, and see the changes in the size of the tongue, and how quickly it goes down. Learn your dogs response to the different environments, and be careful when you head south for an early season hunt test or trial. I have been to Nashville at the end of May the last 2 years, only 5 hours away, but the difference in temp and humidity did effect the dogs as they were used to more spring weather in Ohio. Try different things in training to help the dog cool and learn what works better.

Another very important point:
Do not swim your hot dog to cool it then put in put in a box/tight crate. Remember, evaporation can not take place in a tight space, and the box will turn into a sauna. Carry a stake out chain, and let the dog cool and dry before putting it up.

Whew!! Did not think this would get so long. I hope this is easy to understand and helps provide some info that will be useful.

Remember: Prevention, learn your dog. It is worth the time and effort. Now all we need is for spring to get here and we can hit training hard!!

Nate Baxter, DVM
Northstar Labradors
Lebanon, OH
North Star's Lady Raven, MH, WCX

Further Treatment at the Veterinary Clinic

Dr Denise Mankin , DVM

© 2005

Pretty good summary........I would like to re-emphasize a couple points. Keep in mind, working in an emergency practice, this is one of the summer things we see very frequently. There are common mistakes we see over and again, mistakes that cost dogs their lives.

First, keep in mind that panting very heavily is not the only sign. If you notice your dog becomes wobbly, or lies down and will not get back up along with the panting, chances are there is a problem with internal temperature.

If you have a way to rapidly check the temperature (digital thermometer), it can be extremely important information. If not, that is not something to fuss over.

Definitely begin cooling the dog, if you have the means. Wet down the coat thoroughly. Indeed you do not want to over cool the dog........that is just as detrimental as the high temperature.

When a dog overheats, the circulatory system goes into shock. Circulation changes to preserve the most vital organs, in an attempt to cool and save them. Circulation is rapidly compromised to the stomach and intestines, even with a milder case of heat stroke. When there is a lack of circulation to the GI tract, it begins to die. The first thing to die is the intestinal lining.......heat stroke dogs develop bloody diarrhea due to this (we see intestinal lining in the diarrhea, literally). When the lining is compromised or lost, bacteria and toxins are rapidly absorbed, causing sepsis.

Also, clotting factors are destroyed with heat stroke, if severe enough or prolonged. This results in bleeding problems, and you will begin to see bruising on the skin or mucous membranes.....eventually, if bad enough, it leads to DIC or disseminated intravascular coagulation (we also term that DIC = Dead In Cage.....there is little that can be done for these dogs).

So, after you start to cool the dog, drive quickly to the nearest vet.

IV fluids should be POURED into the dog (we generally use both crystalloid and colloid to prevent the fluids from seeping out of the circulation and resulting in edema in the tissues), rapidly at first to restore circulation. Broad spectrum antibiotics and GI protectants should be started, and bloodwork should also be started once IVs and meds are on board. Clotting factors should be analyzed.

I would suggest if the veterinarian you are working with does not have all the equipment to do in house labs, and does not have fluids other than Lactated Ringers, or similar, and has not dealt with alot of heat stroke, AFTER initial stabilization (improving circulation, stabilizing the temperature without overcooling, initial meds, etc), it may be good to consider referral to a facility that can continue stabilization.

I would always emphasize that if you notice possible signs, seek medical attention for your dog!!!!! Waiting, thinking all is okay can complicate things.......the dog may get beyond the point of help. And yes, I have seen this far too many times. One very good example was a springer spaniel. Outside playing, came in and seemed wobbly and tired to the owner. They let it lie down, gave him water, etc. HOURS later, he was not moving, had vomited. They brought him in 5-6 hours after they first noticed he was wobbly. We treated very aggressively, but he developed bloody diarrhea, and was having clotting problems. He was euthanized at the daytime clinic later the next day. Keep in mind, his symptoms were not that bad initially.......

All in all, be very careful!!!

And keep in mind that 75 degrees can sometimes be too hot for a dog to be playing (that seems especially true of Labs, who are more susceptible to heat stroke...but that is a different story).

• Death in a Hot Car : the deadly danger of leaving a dog in a car trusting the A/C to keep running.