Comparison of serum tryptase as a diagnostic oncological marker in canine versus human mast cell neoplasms.

Canine mast cell tumors (MCTs) are a promising translational model for human mast cell neoplasms with striking similarities such as the Darier's sign and mutations in the KIT gene. Whereas mast cell neoplasms are rare in humans, MCTs are the most frequent malignant neoplasms of the skin in dogs. In human systemic mastocytosis, serum tryptase is an important diagnostic criterion. Surprisingly, serum tryptase levels were not yet investigated in dogs with MCTs. Therefore, the aim of this study was to investigate whether serum tryptase levels in dogs with cutaneous MCTs were elevated compared to those of a non-MCT control group. As a secondary aim, it was investigated whether surgical manipulation caused an increase in serum tryptase in canine MCT patients. A total of 48 serum samples were collected from dogs with different grades of cutaneous MCTs (n = 24) and non-MCT controls (n = 24). In dogs with cutaneous MCTs, blood was collected prior to and within 1 h after surgery. Serum tryptase levels were measured using a commercially available canine-specific ELISA kit. No significant difference in serum tryptase levels was found between cutaneous MCT patients and non-MCT controls, nor in these levels before versus after surgery. Our findings in canine cutaneous MCTs are in accordance with human cutaneous mastocytosis, where serum tryptase levels tend to remain within the normal range. However, despite various similarities between aggressive mast cell tumors in dogs and humans, serum tryptase cannot be considered a diagnostic biomarker in dogs with cutaneous MCTs as part of a comparative oncologic strategy.

Intra- and interobserver agreement on radiographic phenotype in the diagnosis of canine hip dysplasia.

OBJECTIVE: To investigate the repeatability and reproducibility of the presence of a circumferential femoral head osteophyte (CFHO), a curvilinear caudolateral osteophyte (CCO), osteosclerosis of the cranial acetabular edge (Scler CrAE), degenerative joint disease (DJD), and the diagnosis of suspected canine hip dysplasia (CHD) in different groups of experienced observers. STUDY DESIGN: Cross-sectional study. SAMPLE POPULATION: Standard hip extended radiographs (n = 50). METHODS: Nine experienced observers were divided into 3 groups: surgeons (DECVS), radiologists (DECVDI), and non-board certified observers (NBC) and 2 subgroups (academics and non-academics). Cohen's kappa (κ) was calculated for CFHO, CCO, Scler CrAE, DJD, and suspected CHD, and weighted κ was calculated for DJD score to determine inter- and intraobserver agreement. RESULTS: Intraobserver agreement on CFHO, CCO, Scler CrAE, DJD, and suspected CHD ranged from slight to almost perfect, but was not significantly different between NBC, DECVS, and DECVDI. Radiologists and non-board certified observers had a more uniform scoring than surgeons on the overall DJD score, as did academics versus non-academics. Interobserver agreement for NBC was more uniform than that of radiologists and surgeons on CCO and DJD. NBC and radiologists scored more uniformly than surgeons on CFHO, and radiologists scored more uniformly than NBC and surgeons on Scler CrAE. Academics scored more uniformly than non-academics, but only significantly for Scler CrAE. CONCLUSIONS: Recognition of specific radiographic markers is only fairly reliable within and between experienced observers. Therefore, care must be taken to apply these traits in official screening, surgical decision-making and scientific research.

Worldwide screening for canine hip dysplasia: where are we now?

OBJECTIVE: To critically review the different screening systems used for canine hip dysplasia (CHD) and their impact on the prevalence of the disease. STUDY DESIGN: Critical literature review. METHODS: Literature search through PubMed (November 1959-October 2011) and the Orthopedic Foundation for Animals (OFA), Fédération Cynologique Internationale (FCI), British Veterinary Association/Kennel Club (BVA/KC), and Pennsylvania Hip Improvement Program (PennHIP) websites. RESULTS: The OFA, FCI, and BVA/KC screening methods, which use the hip-extended radiographic projection, have had relatively minor success on CHD prevalence. These screening approaches are prone to conflicting data regarding interobserver agreement. The PennHIP and Dorsolateral Subluxation (DLS) systems, both distraction methods, have not reported on prevalence but seem to be important heritable traits in genomic screening of dysplastic dogs. CONCLUSION: A shift towards genome screening yields a promising future combating CHD, although further investigation towards fine-mapping in the search for genes, responsible for CHD, is necessary.

The effect of a technical quality assessment of hip-extended radiographs on interobserver agreement in the diagnosis of canine hip dysplasia.

Experienced and inexperienced observers evaluated the assessability of 50 radiographs (25 dogs) and determined the hip status (dysplasia/nondysplasia and final scoring according Fédération Cynologique Internationale [FCI]-criteria) individually. A radiographic technical quality assessment was performed in a separate reading session. Interobserver agreement in determining dysplasia/nondysplasia and FCI-scoring did not significantly increase with the increasing quality of a radiograph, irrespective whether these observers are experienced or not. There was a significant agreement between the technical quality assessment and assessability (P < 0.0005). Despite the effort to objectify radiographic quality and to present high-quality radiographs to observers, interobserver agreement on dysplasia/nondysplasia and final scoring, remains low, even in the experienced group. Although increased radiographic quality narrows the range of scoring, the range remains unacceptably high.