Hypertrophic osteodystrophy in the dog

Presenting signs and clinical outcome in dogs with metaphyseal osteopathy: 39 cases (2009-2018)

OBJECTIVE

To describe the presenting signs, concurrent conditions, treatment and outcome of dogs with metaphyseal osteopathy.

MATERIALS AND METHODS

Multi-centre retrospective review of medical records from January 2009 to September 2018 at four referral centres to identify dogs with a radiographic diagnosis of metaphyseal osteopathy.

RESULTS

Thirty-nine dogs were identified. The median age at onset was 14 weeks old (range, 8 to 32 weeks old). There was a higher proportion of male dogs (29 of 39 male entire, nine of 39 female entire, one of 39 female neutered and no male neutered dogs). Where information was available, median time from the most recent vaccination was 20 days (range, 2 to 144 days). The most commonly recorded clinical signs were pyrexia (34 of 39), lethargy (32 of 39), pain (30 of 39), and being non-ambulatory (17 of 39). Thirty-five dogs required hospitalisation for analgesia and supportive care, 19 of 39 were discharged on prednisolone (median dose 2.0 mg/kg/day; range, 0.9 to 2.6 mg/kg/day), 18 of 39 were discharged on non-steroidal anti-inflammatories, two of 39 did not receive NSAIDs or prednisolone at any time point. The median duration of hospitalisation for those admitted was 5 days (range, 1 to 21 days). Where follow-up was available, relapse occurred in eight of 25 cases before reaching skeletal maturity. At the time of metaphyseal osteopathy diagnosis, five of 39 cases had concurrent conditions. Where follow-up was available, four of 25 developed future immune-mediated conditions.

CLINICAL SIGNIFICANCE

Metaphyseal osteopathy should be considered in non-ambulatory painful young dogs. Some dogs developed future immune-mediated conditions, which may support the hypothesis that metaphyseal osteopathy is an autoinflammatory bone disorder. Further studies with a larger cohort are required to determine the clinical significance of this.

Hypertrophic osteodystrophy in dogs: diagnosis and treatment

Hypertrophic osteodystrophy is an uncommon orthopaedic disease that affects young, growing dogs. Aetiology is currently unknown; however, several unproven etiologies have been theorised in the literature including canine distemper virus, previous vaccination, hereditary causes and auto-immune disorders. Affected animals often present with varying degrees of lameness, lethargy, pyrexia and/or distal metaphyseal swelling of affected limbs. An index of suspicion is based on clinical signs. Confirmation is obtained with radiographs of the affected limb(s) by the presence of a "double physis," or a radiolucent line that is parallel to the physis. Treatment varies depending on degree affected, but generally consists of anti-inflammatory steroids, pain medications, gastrointestinal support, nutritional management and appropriate supportive care. Critically affected patients require intensive monitoring and more aggressive supportive care for prevention of life-threatening sequalae. Prognosis is very favourable with mildly and moderately affected patients, but good to guarded in severely affected patients.

Juvenile Disease Processes Affecting the Forelimb in Canines

Several juvenile diseases affect the canine forelimb. The most common are hypertrophic osteodystrophy, panosteitis, and retained cartilaginous core. Panosteitis and hypertrophic osteodystrophy tend to be self-limiting, with a good long-term prognosis, although severe cases can develop. These diseases may recur during growth. Severe cases of hypertrophic osteodystrophy can lead to angular limb deformities and may even be fatal. Retained cartilaginous cores can be benign with no evidence of clinical signs and be found incidentally on radiographs. However, if they disrupt the distal ulnar physis, angular limb deformities may persist requiring surgical intervention with a corrective osteotomy.

Metaphyseal osteopathy-like disease in two sibling kittens

This report describes the diagnosis and treatment of a growth plate disturbance resembling canine metaphyseal osteopathy in two, two-month-old, sibling, intact, female Domestic Shorthair cats. Clinical signs and radiographic lesions resolved spontaneously after three months. Follow-up examination at six months of age showed complete recovery and no radiographic abnormalities.

Metaphyseal osteopathy in three Australian Kelpie siblings

CASE REPORT

Metaphyseal osteopathy (MO) was diagnosed in three Australian Kelpie puppies that were presented for veterinary assessment of lameness. The three puppies were siblings. Each was from a different litter by the same breeding pair. The puppy in case one was seen by the authors, and the puppies in cases two and three were patients at other veterinary hospitals. However, the medical records and radiographs were examined and reviewed for this report. Radiographic investigation of the lameness revealed pathognomonic appearance of MO affecting the metaphyseal region of the long bones in all three puppies. The diagnosis was confirmed on histopathology in one patient.

CONCLUSION

MO is considered a disease of large and giant-breed dogs, being rarely reported in non-large-breed dogs, and has not been reported in the Australian Kelpie, which is considered a medium-breed dog. This case series suggests a previously unreported breed predisposition to MO in the Australian Kelpie.

Clinical manifestations, response to treatment, and clinical outcome for Weimaraners with hypertrophic osteodystrophy: 53 cases (2009-2011)

OBJECTIVE

To evaluate clinical manifestations, response to treatment, and outcome for Weimaraners with hypertrophic osteodystrophy (HOD).

DESIGN

Retrospective case series.

ANIMALS

53 dogs.

PROCEDURES

Medical records were reviewed for signalment, vaccination history, clinical signs, laboratory test results, response to treatment, and relapses. Radiographs were reviewed.

RESULTS

Clinical signs included pyrexia, lethargy, and ostealgia; signs involving the gastrointestinal, ocular, or cutaneous systems were detected. Of the 53 dogs, 28 (52.8%) had HOD-affected littermates. Dogs with HOD-affected littermates were more likely to relapse, compared with the likelihood of relapse for dogs with no HOD-affected littermates. All 53 dogs had been vaccinated 1 to 30 days before HOD onset; no difference was found between the number of dogs with a history of vaccination with a recombinant vaccine (n … 21) versus a nonrecombinant vaccine (32). Fifty (94.3%) dogs had radiographic lesions compatible with HOD at disease onset, and the other 3 (5.7%) had HOD lesions 48 to 72 hours after the onset of clinical signs. Twelve of 22 (54.5%) dogs treated with NSAIDs did not achieve remission by 7 days after initiation of treatment. All dogs treated initially with corticosteroids achieved remission within 8 to 48 hours. Of the 33 dogs that reached adulthood, 28 (84.8%) were healthy and 5 (15.2%) had episodes of pyrexia and malaise.

CONCLUSIONS AND CLINICAL RELEVANCE

Treatment with corticosteroids was superior to treatment with NSAIDs in Weimaraners with HOD. It may be necessary to evaluate repeated radiographs to establish a diagnosis of HOD. Most HOD-affected Weimaraners had resolution of the condition with physeal closure.

Expanded dog leukocyte antigen (DLA) single nucleotide polymorphism (SNP) genotyping reveals spurious class II associations

The dog leukocyte antigen (DLA) system contains many of the functional genes of the immune system, thereby making it a candidate region for involvement in immune-mediated disorders. A number of studies have identified associations between specific DLA class II haplotypes and canine immune hemolytic anemia, thyroiditis, immune polyarthritis, type I diabetes mellitus, hypoadrenocorticism, systemic lupus erythematosus-related disease complex, necrotizing meningoencephalitis (NME) and anal furunculosis. These studies have relied on sequencing approximately 300 bases of exon 2 of each of the DLA class II genes: DLA-DRB1, DLA-DQA1 and DLA-DQB1. In the present study, an association (odds ratio=4.29) was identified by this method between Weimaraner dogs with hypertrophic osteodystrophy (HOD) and DLA-DRB1∗01501. To fine map the association with HOD, a genotyping assay of 126 coding single nucleotide polymorphisms (SNPs) from across the entire DLA, spanning a region of 2.5 Mb (3,320,000-5,830,000) on CFA12, was developed and tested on Weimaraners with HOD, as well as two additional breeds with diseases associated with DLA class II: Nova Scotia duck tolling retrievers with hypoadrenocorticism and Pug dogs with NME. No significant associations were found between Weimaraners with HOD or Nova Scotia duck tolling retrievers with hypoadrenocorticism and SNPs spanning the DLA region. In contrast, significant associations were found with NME in Pug dogs, although the associated region extended beyond the class II genes. By including a larger number of genes from a larger genomic region, a SNP genotyping assay was generated that provides coverage of the extended DLA region and may be useful in identifying and fine mapping DLA associations in dogs.

Developmental orthopedic disease

Developmental orthopedic diseases are a common cause of pain and lameness in young dogs. Most occur in large-breed dogs with rapid growth rates. This article reviews the signalment, etiology and pathogenesis, clinical signs, diagnosis, treatment, and prognosis for many of the common developmental orthopedic diseases, including hypertrophic osteodystrophy, panosteitis, osteochondrosis, Legg-Calve-Perthes disease, hip dysplasia, elbow dysplasia, and pes verus.

Forelimb lameness in the young patient

Forelimb lameness is a common problem in young dogs and can be caused by a wide variety of problems. Accurate and comprehensive diagnosis and treatment must be provided for these patients. Differential diagnoses for forelimb lameness in the young patient fall into the categories of congenital abnormalities; developmental disorders; trauma; and infectious, nutritional, metabolic, and neoplastic causes. The etiopathogeneses of many of these disorders are still unknown, and treatment options and prognoses vary tremendously. Until definitive causes are determined, it is the responsibility of veterinarians to address the factors that contribute to the development and progression of these disorders. These areas primarily involve weight and nutritional management as well as breeding programs.

Canine hypertrophic osteodystrophy, a study of the spontaneous disease in littermates

All members of a weimaraner litter had clinical and radiographic signs of hypertrophic osteodystrophy shortly after weaning. Three dogs were necropsied. Radiographic metaphyseal densities, which are used to make a clinical diagnosis of hypertrophic osteodystrophy, were found to result from elongation of the calcified cartilage lattice of the primary spongiosa. Intertrabecular acute inflammation was associated with necrosis, failure to deposit osseous tissue on the calcified-cartilage lattice, and trabecular microfractures. This process led to metaphyseal infraction and separation of the epiphysis. Defective bone formation (osteodystrophy) was considered a secondary process resulting from inflammation of osteochondral complexes, marrow, and periosteum. Enamel hypoplasia also was found to be associated with inflammation of the dental crypt, and abnormal enamel matrix was observed in the developing teeth. The histopathology of the bones and teeth was different from alterations which occur in infantile scurvy or congenital syphilis, although these diseases of man have radiographic similarities to canine hypertrophic osteodystrophy. Because the radiologic lesion is nonspecific, a clinical diagnosis of hypertrophic osteodystrophy is not necessarily diagnostic of a specific disease due to a single etiologic agent. Liver levels of ascorbic acid were within the normal range. Although an infectious agent could not be identified, the conditions may have an infectious origin with systemic manifestations.