Bone dysplasia in the radial and ulnar metaphysis of a Newfoundland dog.

A recently described metaphyseal irregularity of the radius and ulna was diagnosed radiographically in a significant proportion of Newfoundland dogs during the course of a large study. This case report describes the pathological picture of a Newfoundland dog with these radiographic changes. The lesions in the distal radius and ulna were characterized by focal, longitudinal striations of sclerosis of the bone marrow cavity, surrounding thin trabeculae of primary spongiosa of the distal metaphysis. It is suggested that these lesions represent a sclerosing dysplasia not previously described in dogs, but with some similarities to the human disorder, osteopathia striata.

Risk factors affecting metaphyseal irregularities in the radius and ulna of growing Newfoundland dogs.

The main objective of this study was to study risk factors affecting metaphyseal irregularities (MI) in the distal radius and ulna of growing Newfoundland dogs. Risk factors studied included the genetic effects, effects of litters, BW, circumferences of the distal radius and ulna (CDRU), and total serum alkaline phosphatase (ALP) concentrations. The study included 118 Newfoundland dogs (60 females, 58 males), derived from 32 litters. Body weight, separated on sex and MI, was fitted to the Gompertz function. Occurrence of MI differed significantly between sexes, with 55% of males and 35% of females affected (P = 0.03). Growth curves for the 2 groups of dogs, with and without MI, diverged after 60 to 70 d, and dogs with irregularities were heavier at maturity than dogs of the same sex without irregularities. In univariate analysis, the litter effect was a significant predictor of MI, explaining 32% of total variability of the MI incidence, but the genetic effects were not significant. However, the latter were significant in bivariate analysis of MI and BW. In the bivariate analysis, the effects of litter on MI and BW were significantly correlated at all observational points except at birth, 180 d, and 536 d. Total ALP concentrations decreased with increasing age, and differences between groups diminished with increasing age, indicating a negative effect of total ALP on MI. Correlation between MI and total ALP concentrations of litters was estimated in a bivariate analysis. This correlation was significant and ranged between -0.34 and -0.62. Similarly, the genetic relationship between total ALP and MI from 120 d of age onward varied between -0.31 to -0.60. However, correlations were only significant at 356 d of age (genetic correlation = 0.60; P = 0.01). The mean CDRU increased from 90 d of age toward a peak at 180 d. Thereafter, CDRU declined and stabilized at about 1 yr of age. The mean CDRU between the groups of dogs with and without MI diverged most at 90 d of age, then was nearly stable until 180 d and gradually declined until 356 d, when the CDRU began to equalize. Metaphyseal irregularities and CDRU levels of litter were significantly correlated. Litter effect was a significant predictor of MI. The effects of litters and the genetic effects on BW and MI were correlated at most phases of the growth of the dog. Similar, but lower, correlations were found for CDRU and MI, and total ALP and MI.

A longitudinal study on growth and growth variables in dogs of four large breeds raised in domestic environments.

The main objective of this study was to describe the growth patterns of 4 large dog breeds [Newfoundland (NF), Labrador retriever (LR), Leonberger (LEO), and Irish wolfhound (IW)] raised in domestic environments and concomitant changes in 2 growth-related clinical variables: total serum alkaline phosphatase (ALP) and the circumference of the distal radius and ulna (CDRU). The second objective was to investigate whether these measurements were affected by a range of independent variables like age, sex, litter number, and birth weight. Seven hundred dogs were included in the study, and BW data, separated by breed and sex, were fitted to the Gompertz function. Birth weight, adjusted for litter number, differed significantly between sexes for 3 breeds (LEO, P = 0.004; NF, P = 0.02; LR, P = 0.009) and approached significance for IW (P = 0.07). Estimated mean BW increased rapidly during the first 100 d after birth in all 4 breeds, then plateaued, with maturity being reached between 351 (female LR) and 413 d (male NF). Estimated mature BW ranged from 30.8 kg for the female LR up to 65.7 kg for the male IW. Weight gain, as expressed by the derivative of the Gompertz function, reached its peak in the smallest breed (LR) at the youngest age, 89 d for the females and 95 d for males. Log-transformed BW was significantly related to age, breed, and sex, and the age x sex and age x breed interactions. Within breeds, age, birth weight, and litter number had a significant effect on log-transformed BW. The estimated average CDRU increased from 90 d of age toward a peak at 180 d. Thereafter, CDRU declined and stabilized at about 1 yr of age. The estimated total ALP concentrations decreased from 90 to 360 d of age, after which they stabilized, at mean concentrations varying among breeds from 98 to 131 IU/L. Maximum least squares mean total ALP concentrations were found at 3 mo of age in all breeds, with the greatest least squares mean concentration in the IW breed (713 IU/L). In a mixed model analysis of the complete data set, total ALP was affected (P < 0.001) by age, breed, and the interaction of age x breed. This study described the main factors influencing growth and provided reference data for other studies, including those related to nutrition and disorders of growth.

Pancreatic insulin-secreting carcinoma in a dog: fructosamine for determining persistent hypoglycaemia.

A five-year-old intact male rottweiler was presented with a history of episodic weakness and mild-generalised seizures. A tentative diagnosis of an insulin-secreting tumour in the pancreas was made based on fasting hypoglycaemia with concomitant hyperinsulinaemia and a subnormal fructosamine value. The diagnosis was confirmed by exploratory coeliotomy, intravenous infusion of methylene blue, histopathology and immuno-histochemical analysis of suspected neoplastic tissue. Fructosamine assays are traditionally used for monitoring the metabolic status of diabetics where a single elevated measurement reflects persistent hyperglycaemia. This report suggests that a single low measurement of fructosamine may indicate persistent hypoglycaemia and may be helpful, in conjunction with an insulin measurement, in the diagnosis of insulin-secreting tumours.

Arthrosis in the elbow joint of young rapidly growing dogs. VI. Interrelation between clinical, radiographical and pathoanatomical findings.

In 106 dogs in which one, two or more of the lesions A: Fragmentation of the coronoid process, B: Fissure of the coronoid process, C: Osteochondritis dissecans of the humeral condyle, or D: Ununited anconeal process, were found at autopsy, comparisons were made between clinical, radiographical and pathoanatomical findings. The 38 dogs which were put to death because of persistent lameness, represented young dogs of larger breeds only, while dogs of which no prehistory regarding foreleg lameness was given, or which had never revealed foreleg lameness, were older and represented dogs of smaller breeds as well. The lesion A was the most predominant finding, and the incidence of lesions A and A + C was slightly higher among lame legs than among legs free from lameness. Routine radiography was a reliable tool in interpreting osteochondritis dissecans, ununited anconeal process and degree of osteophyte formation when compared to the pathoanatomical examination, while lesions of the coronoid process was infrequently diagnosed by routine radiography. When comparing the various observations made clinically, radiographically and patho-anatomically, statistically significant correlations were found between all the parameters exept decreased flexibility/supination, decreased flexibility/pain and pain/arthrosis. The degree of arthrosis was higher in joints descending from lame legs than in joints descending from legs free from lameness, but was relatively high even in the latter group. The reasons why some dogs get lame in contrast to others suffering from the same lesions, are discussed.

Arthrosis in the elbow joint of young rapidly growing dogs. VII. Occurrence in the Rottweiler breed.

The author has previously shown that lesions of the coronoid process are the most common reason for elbow lameness and osteophyte formation of the elbow joint in the Rottweiler and other larger breeds. To get more information regarding the elbow status of the Rottweiler breed, 207 dogs were radiographically investigated. Of these, 66 dogs were admitted because of elbow lameness, while 141 dogs more than 12 months of age, had never revealed foreleg lameness. Osteophyte formation was found in one or both elbow joints in 89.4% of the lame dogs and in 68.1% of the dogs free from lameness. When trying to elucidate the probability of inheritance, the dogs were grouped according to the elbow status of the parents. The results indicate that the percentage of lame offspring and offspring affected by osteophyte formation increases according to increase in affected elbow joints of the parents. Inherited disposition for lesions of the coronoid process is therefore suggested. Prophylactical criteria are discussed.

Arthrosis in the elbow joint of young rapidly growing dogs. V. A pathoanatomical investigation.

During a 3 year period the elbow joints of dogs subjected to autopsy were specially subjected to autopsy were specially investigated regarding the lesions A Ununited or fragmented coronoid process, B Fissure of the coronoid process, C Osteochondritis dissecans of the humeral condyle, and D Ununited anconeal process. Other findings as erosions, wear and tear furrows and degree of osteophyte formation at different locations, are described. The lesions A, B, C and D were seen in 120 dogs and the Rottweilers, the Retriever breeds and the German Shepherd Dogs were most disposed although lesions of the coronoid process were seen in dogs of different size as in a Miniature Poodle and a Pomeranian. Fragmented coronoid process was the lesion most frequently seen among the affected breeds. Fissure of the coronoid process was most frequently seen among Rottweilers while osteochondritis dissecans of the humeral condyle was a frequent finding among Golden Retrievers. Ununited anconeal process was only seen in 7 of the 236 joints investigated. This lesion was the one leading to the highest degree of osteophyte formation. Next to this were fragmented coronoid process and osteochondritis dissecans, while fissure of the coronoid process led to a small degree of osteophyte formation. Histopathological investigation of the coronoid process revealed that fissure and fracture lines occurred in joints in which no degeneration of the joint cartilage was detected, as well as in joints in which thickened and degenerated hyalin cartilage (osteochondrosis) was seen. The authors conclude that fissures seem to be an early stage of fragmentation, but do not necessarily lead to fracture. The condition may be due to osteochondrosis, to general or local overloading of normal tissue or to generalized weakness of the joint cartilage and the bone in combination with mechanical overloading. The term fragmentation of the coronoid process, as proposed by Olsson in 1976, is a more appropriate term for the condition than the previously used ununited coronoid process.

Arthrosis in the elbow joint of young rapidly growing dogs. IV. Ununited anconeal process. A follow up investigation of operated dogs.

During a 5 year period ununited anconeal process was diagnosed in 37 dogs. Thirty one of these were German Shepherd Dogs and the ratio male:female was about equal. Thirty-four of the dogs (44 joints) were surgically treated by removal of the process. When judged by the owners of 28 dogs 3 months to 5 years postoperatively, average time interval being 30.6 +/- 16.6 months, 46.4% were assessed to be free from lameness, 35.7% were occasionally lame and 17.9% were constantly lame or euthanized because of lameness. Sixteen of the dogs (23 joints) were clinically and radiographically re-examined by the authors. Except for 3 of the dogs which were judged to be free from lameness, the dogs were more or less stiff or lame when examined. The degree of arthrosis had increased from the time of surgery until re-examination and tended to be more pronounced according to increase in time interval.

Arthrosis in the elbow joint of young rapidly growing dogs. III. Ununited medical coronoid process of the ulna and osteochondritis dissecans of the humeral condyle. Surgical procedure for correction and postoperative investigation.

A surgical procedure for medial arthrotomy in the elbow joint is described. Surgery was performed in an endeavour to remove an ununited coronoid process and/or a loose piece of cartilage from the humeral condyle. A long term follow up investigation of 58 operated and 20 unoperated dogs was undertaken. The prognosis of dogs operated upon because of osteochondritis dissecans of the humeral condyle, was fairly good; 11 of 15 dogs (73.3%) being reported as showing no signs of lameness. When dogs with the both diagnoses were judged together, the percentage of dogs reported not to be lame was 48.3 among operated dogs and 45 among unoperated dogs. However, dogs operated upon, recovered somewhat sooner than unoperated dogs. Of 38 dogs (58 joints) which were clinically and radiographically re-examined by the author, it was found that severe arthrosis (degree 3) developed in about 60% of the joints, no matter whether surgical treatment was carried out or not. However, 19 of these dogs were not lame, or only revealed lameness occasionally.

Arthrosis with special reference to the elbow joint of young rapidly growing dogs. I A review of the literature.

The terms arthrosis, arthritis, osteochondrosis, osteochondritis dissecans and dysplasia are defined. A short review of the pathological anatomical changes seen in primary and secondary arthrosis is given, and the anatomy of the elbow is briefly described. The literature concerning elbow lesions leading to arthrosis in young, rapidly growing dogs is reviewed.

Arthrosis with special reference to the elbow joint of young rapidly growing dogs. II. Occurrence, clinical and radiographical findings.

Occurrence, clinical and radiographical findings in ununited medial coronoid process in the ulna and osteochondritis dissecans in the humeral condyle in dogs are presented. One hundred and twelve dogs were examined because of forelimb lameness. Lesions were mostly seen in young dogs of heavy breeds especially the Rottweiler. The ratio male: female was about 2:1. Most of the dogs had bilateral lesions. The lameness varied between grade 1 and 3, judged according to a scale ranging from 1 to 5. The affected limbs were somewhat rotated outwards from the elbow and down. Since the ununited coronoid process is almost impossible to detect on a plain radiograph, it is necessary to look for the presence of secondary developed osteophytes, indicative of an arthrosis. Diagnosis is based upon clinical and radiographical findings, the age and the breed of the dog taken into consideration. Osteochondritis dissecans in the humeral condyle is usually easily seen on the dorsopalmar radiograph.