Nutritionally Responsive Conditions Part 3


Nutritionally Responsive Conditions

Lecture Notes

Now switching to a different system


What are we going to talk about?

Lecture Notes

We will study skeletal development disorders.


Skeletal Development Diseases

Lecture Notes

If you own a dog, especially a large breed dog, you have probably heard these terms. Osteochondrosis, hypertrophic osteodystrophy, and hip dysplasia are common conditions among large breed dogs. All of them are considered skeletal development diseases or disorders. Therefore, we need to study what factors affect skeletal development.


Factors influencing skeletal development

Lecture Notes

Skeletal development in dogs is affected by three main factors. The genetic factor includes the breed of the animal and its predisposition to diseases. Genetics will define how big your dog will be, how fast he will grow, and depending on other factors, if he will develop some skeletal problem. Nutrition affects how your dog will grow and consequently the skeletal development. Environmental factors such as exercise and type of floor will also be vital in the development of the skeletal system, and therefore another important tool in the prevention and treatment of these type of disorders


Would they grow at the same rate?

Lecture Notes

The variation in dog sizes is unique to this species. We can imagine that these dogs didn't grow at the same rate from puppies to adults, and we are not even comparing this Irish Wolfhound with a Yorkie or a Chihuahua.


Mean growth curves for 12 breeds of dogs

Lecture Notes

This graph shows the growth curves for 12 breeds of dogs. The whole graph is impressive, but if we compare the growth of smaller breeds and large breeds from four months to eight months of age, we can see that large breed puppies doubled their body weight in this period, whereas smaller breeds had a more modest increase in theirs. If you wonder why it makes a difference, think about driving at 30 miles per hour and driving at 80 miles per hour. Are the risks of getting involved in a car accident the same? Obviously not; that's why large breed dogs with their fast growth rate are more prone to skeletal development disorders. The ideal situation is to have our large breed puppies to gain weight as slow as possible, so they aren't putting too much weight on a skeletal structure that is not completely mature.


Environment

Lecture Notes

We also mention environment, which includes many things that are out of our control. However, exercise and housing are relatively easy to manage. We have to provide an adequate amount and intensity of exercise to growing dogs, which will allow a normal development of bones and muscles. Both excess and lack of exercise can be very harmful and increase the risk of skeletal disorders.


Nutrition

Lecture Notes

Finally nutrition. This is the single most important factor that can affect skeletal development. Additionally, it's easier to modify and have been proven to have a dramatic effect on the skeletal development diseases


Diet with 3.3 % calcium

Lecture Notes

Look at this puppy at the beginning of the experiment and after three months of being fed with 3.3% calcium, which represents only three times the calcium requirement for growing puppies. It's evident that it doesn't take too much to cause a skeletal development alteration with only a little bit more calcium.


Is HOD reversible?

Lecture Notes

But is this condition reversible? Well, it depends on the moment it's diagnosed. If it is done early and proper measures are taken, it can be reversed. We can see these pictures a puppy that was suffering from HOD. After being diagnosed and diet corrected he went back to normal in a few months. In this case, the only thing they did to treat him was to change his diet and give him a complete and balanced food for large breed puppies.


Nutrients Affecting Bone Development

Lecture Notes

In general, nutrition affects bone development but especially energy and calcium are more important. Initially protein was thought to have an effect, but it's been proven that it is not true. We have to remember that growth means two things: elongation of the bones and gain weight. An excess energy intake will lead to an excessive gain weight on a skeletal structure that might not be ready to support all this weight. It's like building a house; if the bases are not completely solid and ready, and you start putting walls, roof, bricks, etc., that house will probably fall or have serious issues. That is the case of hip dysplasia.

Calcium, on the other hand, affects the metabolism of the bone growth plates. An excess of calcium will alter the speed and quality of bone growth, causing an imbalance growth and bone diseases.

 


Nutritional management

Lecture Notes

Knowing that energy and calcium are the most important nutrients in the management of the skeletal development, we will focus mainly on those two nutrients.

In skeletal development the phrase "slow down to run further" applies perfectly. Energy intake must be restricted in order to have a moderate growth rate. Therefore, large breed puppies should be fed controlled amounts of a food that is specially formulated for them. That food should have a lower energy and calcium concentration than a regular puppy food.

We saw that a slight excess in calcium intake could be very detrimental for the skeletal development, so do not supplement calcium unless indicated by your vet. Calcium is the cheapest ingredient in the food industry, thus any commercial food, even the cheapest one, has more than enough calcium to support puppies' growth.

Finally, in case of any sign of impaired growth or bone abnormalities take your dog to the vet for an early diagnostic.