Page 666 - Small Animal Clinical Nutrition 5th Edition

DOD of Dogs 689

caused slight crepitation and elicited a painful response, especially with hyperflexion of the joint. Radiographs of the shoulder joints
were obtained (Figure 1).
VetBooks.ir Assess the Food and Feeding Method

The puppy was initially fed a commercial dry food formulated for growth (protein = 29%, fat = 18%, calcium = 1.6%, phosphorus
= 1.2%, all values listed on a dry matter basis) free choice. Because the puppy was “such a good eater,” the owner supplemented the
food occasionally with meat and table foods.When the puppy was 14 weeks old, the owner switched foods because the puppy devel-
oped abnormal locomotion, which members of the owner’s dog club attributed to excessive protein intake. The new food was a
commercial dry product formulated for adult maintenance (protein = 20%, fat = 13.3%, calcium = 1.7%, all values listed on a dry
matter basis). The new food was offered free choice because of the puppy’s “good appetite.”

Questions
1. What is the tentative diagnosis and how does this condition cause the clinical signs in this dog?
2. How should this patient be managed?
3. Outline an appropriate feeding plan for this dog.
Answers and Discussion
1. Great Danes and other large- and giant-breed dogs are prone to osteochondrosis in the shoulder joints, especially when exces-
sive energy and calcium are consumed during the period of rapid growth (two to six months of age). Osteochondrosis is a dis-
turbance in endochondral ossification that can result in localized separation of articular cartilage and subchondral bone, and may
lead to splitting of cartilage fragments into the joint, i.e., osteochondritis dissecans. Osteochondrosis is not painful; osteochon-
dritis dissecans causes osteoarthritis and inflammation of subchondral bone, which is painful. A diagnosis of osteochondritis dis-
secans is very likely in this case based on the clinical (painful shoulder joints) and radiologic findings (indentation in the caudal
humeral head).
Because flexion and extension of both shoulder joints is painful with osteochondritis dissecans, dogs will shift their body
weight to the rear limbs, resulting in abnormal locomotion. Dogs with osteochondritis dissecans of the shoulder joints also appear
stiff because of the limited range of joint motion and have variable degrees of lameness.
2. Surgical treatment is indicated for most cases of shoulder joint osteochondritis dissecans when lameness is present and persist-
ing, and when manipulation of the joint is painful. The loose cartilage flap is removed and the flap bed curetted until the sub-
chondral bone bleeds. Granulation tissue and, ultimately, fibrocartilage fill the curetted defect in the articular surface. The joint
is thoroughly irrigated and any floating “joint mice” or bony ossicles attached to the joint capsule are removed. Recovery is pre-
dictable with appropriate surgical treatment. Osteochondrosis and osteochondritis dissecans of the shoulder joint will cause sec-
ondary osteoarthritis, possibly causing clinical problems in later years, although osteoarthritis of the shoulder joint is usually well
tolerated by dogs.
3. Altering the feeding plan may have no beneficial effects on osteochondrosis or osteochondritis dissecans at this stage of the dis-
ease process. Excess energy and calcium intake should be avoided during the rapid growth phase between two and six months of
age.This puppy is slightly overweight; therefore, feeding to maintain a BCS of 2/5 can reduce biomechanical stress on the shoul-

Figure 1. Radiograph of the proximal humerus of an eight-month- Figure 2. Intraoperative view of an osteochondritis dissecans lesion
old male Great Dane puppy examined for forelimb lameness. The in the articular epiphyseal cartilage of the proximal cartilage of the
radiolucent area (arrows) is associated with disrupted endochondral same dog. Note the cartilage flap (A) and exposed subchondral
ossification (osteochondrosis). bone (B) where a portion of the cartilage flap is missing.