Hypertrofisk kardiomyopati hos Maine coon katter

Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats. Maine coon is one of the breeds where the disease is overrepresented. Studies have shown that HCM is inherited as an autosomal dominant trait in Maine Coon cats. This finding has led to cardiac screening using ultrasound in the breed. The results of the screening are used in a national breeding program constructed to reduce the spread and incidence of HCM in Maine Coon cats. The disease is characterized by a broad range of phenotypic patterns which leads to difficulties in interpretation of the ultrasonographic findings and classification of cats in the breeding program. This study reports of different phenotypes in Maine Coon cats which were screened at the Department of Medicine and Surgery during the period January until November 2003. A screening protocol designed by M. D. Kittleson was used to evaluate the cats. It includes a physical examination, ultrasound examination and provides guidelines for the diagnosis of HCM. Thus, depending on the findings in a particular cat, it may be classified as normal, equivocal or HCM. In total, seventeen cats were examined. Four of these cats were diagnosed as equivocal regarding HCM, indicating that the changes in the heart are either an early stage of HCM or a normal phenotype. All the four cats in the equivocal group were classified based on the finding of papillary muscle hypertrophy. The thirteen remaining cats where diagnosed as normal. Nine of these thirteen cats had cardiac anatomical changes interpreted as a normal phenotype. Thus, the proportions cats in which some form of cardiac change were noted (most of them non-pathological changes) or were classified as equivocal were high. Obviously, this complicates the diagnosis. To decide on diagnosis in equivocal cats, several cardiac examinations over time are often required. During this time period, the use of this particular cat for breeding is restricted. Heart changes in equivocal cats can be a normal phenotype and accordingly, there is a potential risk of keeping healthy cats from breeding. When animals are excluded from breeding, this limits the genetic material and increases the risk of selection of cats with other genetic disease. Thereby, it is appropriate as a first step towards a healthier breed, that only cats with diagnosis HCM are excluded from breed.Hypertrofisk kardiomyopati är det vanligaste hjärtsjukdomen hos katt och Maine coon är en av de kattraser hos vilken sjukdomen är överrepresenterad. Studier har visat ärftlighet för sjukdom hos rasen vilket har lett till att Maine coon katter världen över screenas genom undersökning med ultraljud. I Sverige används screeningsresultaten i rasklubbens avelsprogram som nyligen konstruerats för bekämpning av HCM. Sjukdomen karakteriseras av en stor variation fenotyper och problem har därför uppstått vid tolkning av ultraljudsfynd och därmed klassificering av katter i avelsprogrammet. Vi sammanställde screeningsresultat under tidsperioden januari t.o.m. november 2003 för att beskriva de ultraljudfynd som påträffats. Som bakgrund till undersökningen användes ett formulär utformat av M. D. Kittleson som innefattar klinisk undersökning och undersökning med ultraljud samt fastställande av diagnos. Totalt screenades sjutton katter och fyra av dessa fick oviss diagnos. Det innebär att hjärtförändringarna är ett tidig stadie av HCM alt. normal fenotyp. Alla fyra katterna fick oviss diagnos p.g.a. papillarmuskelhypertrofi. Resterande tretton katter fick diagnosen normal. Nio av de tretton katterna i gruppen normala hade hjärtförändringar som tolkades vara normal fenotyp. Studien visade att antalet katter med oviss diagnos var förhållandevis många. Ofta hade katterna någon form av hjärtförändringar (de flesta dock icke patologiska förändringar) vilket försvårar diagnostiseringen. För att säkerställa diagnosen hos katt med oviss diagnos krävs flera screeningar under en längre tidsperiod. Under denna tid har katten restriktioner i avel (enligt rasklubbens avelsprogram). Då hjärtförändringarna hos katt med oviss diagnos kan vara en normal fenotyp finns risk att friska katter hålls från avel. När man på detta sätt väljer att selektera djur och begränsa avelsmaterialet ökar risken för selektion till annan sjukdom. Det är därför lämpligt, som ett första steg mot en friskare ras, att endast katter med diagnosen HCM tas ur avel

Mutations in the CYP27B1 gene cause vitamin D dependent rickets in pugs

Rickets is a disorder of bone development and can be the result of either dietary or genetic causes. Here, related pugs from 2 litters were included. Three pugs had clinical signs including, lameness, bone deformities, and dyspnea. One other pug was found dead. Radiographs of 2 affected pugs, 5 and 6 months old, showed generalized widening, and irregular margination of the physes of both the appendicular and the axial skeleton with generalized decrease in bone opacity and bulbous swelling of the costochondral junctions. Two pugs had low serum calcium and 1,25 (OH)(2)D-3 concentrations. Test results further indicated secondary hyperparathyroidism with adequate concentrations of 25-hydroxyvitamin D. Necropsy revealed tongue-like projections of cartilage extending into the metaphysis consistent with rickets, loss of metaphyseal mineralization and lung pathology. Vitamin D-dependent rickets was diagnosed. A truncating mutation in the 1 alpha-hydroxylase gene (CYP27B1) was identified by genome sequence analysis of the pugs with VDDR type 1A. Vitamin D-dependent rickets type 1A can occur in young pugs, and if left untreated is a life-threatening condition. Early medical intervention can reverse clinical signs and should be instituted as soon as possible