Nutritional Hypothesis:

UPDATED  1/30/01

Jocelyn is a 9 month old, large breed puppy.  She is predisposed to developmental orthopedic disease due to poor nutritional management.  History tells us that her owners feed her large breed IAMs maintanence dog food via free choice.  This allows for excessive consumption of high energy nutrients.  Our hypothesis is that her musculoskeletal development system is growing disproportionately from an excessive diet intake.  

Pathophysiology:

Results of joint laxity - as the subluxtion occurs, the weight bearing contact area of the femoral head and acetabulum is reduced, concentrating over a smaller space.  The joint capsule thickens as the body attempts to stabilize the joint.

Increased body weight and rapid developmental growth of this puppy could lead to degenerative changes.  The stress of the growth could potentially cause inappropriate alignment of the joint and socket.
  
Research:

* (p 505, Small Clinical Nutrition) Prevalence of Musculoskeletal (MS) disorders in dogs less than one year old in all breeds is about 22%, with 20% possibility having a nutrition-related etiology.
o Most commonly fast-growing, large and giant breed dogs
o Canine hip dysplasia and osetochondritis makeup the overwhelming majority of the MS problems with a possible nutrition related etiology.
* Specific factors that are currently thought to increase the risk of DOD in young dogs include:
o Large/ giant breed
o Free choice feeding
o Feeding high-energy foods
o Excessive Ca2+ intake from food, treats and supplements


* The goal of feeding programs for large/ giant breed puppies should achieve moderate energy restriction.
* Meal-limiting feeding is the recommended feeding method for rapidly growing dogs.

IAMS FOOD: The difference between Puppy and Adult Large Breed Dry Food
* There is a difference in Ca and P daily recommendations. 

(p. 516, Small Animal Clinical Nutrition)
* Often puppies are switched from growth to adult maintenance - type foods under the pretense that it will help avoid calcium excess and skeletal disease.  However, because some maintenance foods have much lower energy density than most growth foods, the puppy must consume more dry matter volume to meet its energy requirement.  If the calcium levels are similar (dry matter basis, DMB) between the two foods, the puppy may actually consume more calcium when fed the maintenance food.
* Note: When given an excessive energy dense diet, the puppy's bones will grow too quickly and it's unable to support it's body weight without putting excess stress on the bones.


Ask the following questions to the owners:
* Are you feeding the dog anything else besides its IAMs food?
EX. Treats?  Supplements?
* Confirm the exact IAMs food: Is it Adult Maintenance Large Breed?
* How long are these walks your dog goes on?  Frequency?  Duration?  Intensity?
*  Is anyone home with the dog during the day?
o If not, how long is it alone during the day?
o Is it crate trained?
* How long have you noticed this problem?  How long have you needed to carry this dog up and down the stairs?

Vet/ Hospital Staff should do the following:
* Weigh and assess the BCS of the dog each and every visit to the hospital.
* Take serum tests to check for Ca / P ratio.
* Monitor feeding: Discontinue free choice feeding, i.e. portion control.
* Request radiographs.