Dogs and Human Diseases, Missing the Obvious?

by Mary Haight on July 30, 2010

There was a story here the other day about a new continuous glucose monitoring device for animals to help vets better control insulin levels in diabetics and minimize blood draws in dogs, cats and some larger animals.

A link to a food company owner who talked about how diseases that *can* stem from obesity often have their root in carbohydrate fillers drew some attention. My friend Edie Jarolim read the reference and took exception to language that would lead to the conflation of obesity and diabetes in canines.  The mistaken idea that obesity is the *cause* of canine diabetes has flourished.

Edie will take on that topic in the near future, but it was this conversation that made me wonder what other assumptions are made in the dog and human disease chain?  What’s out there masquerading as a chain of very similar symptoms and actions, when it’s actually missing links?

To help us out with this, I’ve asked another pal, Lorie Huston, DVM, to cite some examples,  make us better, more observant dog caretakers.

Guest Post by Lorie Huston, DVM

As dog owners, it is easy to anthropomorphize our pets and assume that when dogs and people get diseases that share a name, the disease is the same in the two species. In some cases, this is true. In other cases, however, significant differences exist.

Heart disease is one area in which causation is often different in dogs than in humans. In dogs, myocardial infarctions are rare. The most common form of acquired heart disease seen in dogs is degenerative valve disease (DVD), in which the valves located between the heart valves become misshapen and defective leading to a disruption of blood flow through the heart and, eventually, congestive heart failure. The other common cause of acquired heart disease in dogs is dilated cardiomyopathy, a disease of the heart muscle itself that causes the heart to be unable to contract effectively, which ultimately eventually leads to congestive heart failure.

A second example of the incongruity between canine disease and human disease manifestations is thyroid disease. While both hyperthyroidism (including Grave’s disease) and hypothyroidism are reasonably common in people, hyperthyroidism is rarely seen in dogs. Hypothyroidism (or a decrease in the production of thyroid hormones) is the form of thyroid disease almost always seen in dogs.  Hypothyroidism in dogs is most often primary in nature, resulting from a reduction of acinar cells in the thyroid gland. Less commonly, canine hypothyroidism can be a result of a decrease in the production of TSH (thyroid-stimulating hormone) by the pituitary gland.

Hypertension (high blood pressure) is another area where there are significant differences between the disease seen in people and that seen in dogs. Primary hypertension (high blood pressure for which no medical cause can be found) is the most common form of the disease in people. Obesity, sedentary life-style, genetics and diet are often implicated as predisposing factors for primary hypertension. In dogs, however, primary hypertension is rare. Hypertension in dogs is most often secondary to another medical issue, such as diabetes, heart disease, kidney disease or adrenal disease.

As you can see, there are numerous differences between canine and human medicine, even for disease conditions that superficially appear similar to one another.

Thank you Dr. Huston for clarifying these issues for us.

Lorie Huston has been in veterinary medicine for over 20 years in Providence , RI.  Dr. Huston is a successful freelance writer, the feature writer at Suite101.com’s Pet Care section, a National Pet Health Examiner at Examiner.com, publishes her blog, The Pet Health Care Gazette and is The Voice of Pet Care on Facebook. Dr Huston also co-moderates DogTalk, a weekly twitter chat that focuses on a variety of dog topics.

Enhanced by Zemanta
10 comments
Hankster
Hankster

It is always important to realize that animals differ from each other in biochemical and physiological ways - so there have to be differences in both health and disease. For example, as the guest stated in the post, dogs rarely get myocardial infarctions (heart attacks). Part of the reason is that they very rarely get high cholesterol, unless it is secondary to something like hypothyroidism. This is mainly due to the fact that they do not have an enzyme CTEP which is involved in cholesterol transport between HDL (good cholesterol) and LDL (bad cholesterol). In humans higher CTEP activity is linked to an increased rate of development of atherosclerosis leading to an increased risk of heart attack and stroke. Got a bit carried away there with the explanation of CTEP. But my point is that for some body processes dogs and humans are identical and very similar in health and disease, but in other processes dogs and humans have different.

Lorie Huston
Lorie Huston

Hi, Edie. That's probably an accurate statement. I've never done an exhaustive search of the literature and I hate to say "never" about anything, just because it always seems to come back to haunt me when I make an absolute statement like that :-) However, I've never seen a dog that responded to diet alone and I don't know of any of my colleagues who have either. In fact, I do not recommend dietary manipulation alone for dogs for this reason. If they're diabetic, they go right to insulin therapy. There is, however, the issue of diabetes occurring during gestation or cases of severe pancreatitis, in which insulin may not be necessary once the trigger is removed. Look for more on this in my blog in the near future. I hope this clarifies the situation for you a little bit. Sorry if my comment confused you.

Edie
Edie

Lori, I'm going to have to jump in here -- and will expand on this comment in a post -- and say that, in all the research I've done on the topic (including for Your Dog, published by Cummings Veterinary School at Tuftsl), I've never come across research that says *any* diabetic dog can be controlled by diet rather than insulin because the disease is more similar to type 1 diabetes in humans, with a hereditary predisposition. Feline diabetes is similar to type 2 diabetes in humans, which is why it can sometimes be reversed by diet. Of course diet is essential to allowing the insulin to work properly, but, as the owner of a diabetic dog I searched high and low to find cases where the condition was reversed by diet (and that's how I discovered the essential difference of how the condition manifests in cats and dogs).

Champion of My Heart
Champion of My Heart

I stumbled this so that I can keep it filed away for future reference. Having written so much about client communication in veterinary medicine, I can tell you that it's VERY common for pet healthcare workers to use human comparisons to explain things. These are good examples of when such comparisons (and the assumptions people make) can get in our way. Thanks!

Peggy
Peggy

My veterinarian warned me about risks of my dog being a bit overweight. I connected that they were similar to what my own doctor told me, but I love how you are looking deeper and finding the commonality and differences. Thank you!

EdieJ
EdieJ

Great post -- and I really appreciate that, rather than taking offense at my rant about canine diabetes, you used it as a jumping off point to examine how common it is to conflate human with canine symptoms. It makes sense because, as you pointed out in your original post, dogs were used (sadly) as guinea pigs to test many cures for human diseases. And of course there are many similarities; otherwise such testing wouldn't have been been in vain. It's just that the differences need to be observed too.

MaryHaight
MaryHaight

Hi Roxanne. This is an interesting point in communications, isn't it? Our brains can tend to translate what Vets tell us into something we can make a comparison to in an effort to categorize what's happening. If we can't put something in a category that lends familiarity - a sense of "comfortable understanding" - our process may be to just shove that information into a category where it doesn't actually fit! Therefore, we are doomed to repeat thinking about that miscategorized subject in a way that keeps us from understanding where we are mistaken. Phew! What a tangled web...

Lorie Huston
Lorie Huston

Hi, Peggy. Your veterinarian is absolutely right that there are risks involved for dogs that are overweight, just like there are risks for overweight people. Some of the risks are similar and some are a bit different between species but they are real, nonetheless.

Lew Olson
Lew Olson

I will say that I believe carbohydrates in dogs diets can aggravate diabetes in dogs.. and may cause it. Dogs are carnivores and have a short and simple digestive tract. Their digestive tracts are not designed to digest and ferment carbohydrates, and even NRC (National Research Council- the gold standard for canine nutritional needs) states dogs have no nutritional needs for carbohydrates. When you load up a dog with carbohydrates (which are sugars), in my opinion, causes diabetes to show up more frequently. I have seen dogs with diabetes get some control over diabetes by removing carbohydrates. My point is similar to the above blog, in that dogs are different than humans, especially in digestion and nutritional needs. They are built to use animal proteins and fats, and digest them efficiently. Lew Olson

MaryHaight
MaryHaight

Dr Huston emailed this in for you: Hi, Lew. I agree with you (in part) about carbohydrate requirements for dogs. Dogs do not have a dietary need for carbohydrates because they are capable of producing adequate amounts of glucose (through gluconeogenesis) without extraneous carbs being fed. However, they are capable of digesting carbohydrates and some forms of carbohydrates (such as fiber) can actually be advantageous. In regards to diabetes, it seems that it's not so much the type of food that is fed but how it is fed that affects glucose regulation. To make matters even more confusing, the situation in cats is entirely different and you are right about the feline carbohydrate requirement. Check back here on the DDB and on my blog in the near future for more on both subjects: canine diabetes and diet and feline diabetes and diet.

Trackbacks

  1. [...] This post was mentioned on Twitter by Rod Burkert, Doggy Bytes. Doggy Bytes said: Dogs and Human Diseases, Missing the Obvious? http://bit.ly/dDqt6R via @dancingdogblog [...]

  2. [...] to it. I had asked Dr. Lori Huston to first take us through the big picture and look at  other dog and human diseases that can be wrongly associated as being the same in our minds. Today, she’s back to help us clear our memory banks, and replace it with the [...]

  3. [...] Dogs and Human Diseases – Similar Not Same | Dancing Dog Blog [...]

Previous post:

Next post: