What's in a Name? Classification of Diabetes Mellitus in Veterinary Medicine and Why It Matters

Abstract

Diabetes Mellitus (DM) is a syndrome caused by various etiologies. The clinical manifestations of DM are not indicative of the cause of the disease, but might be indicative of the stage and severity of the disease process. Accurately diagnosing and classifying diabetic dogs and cats by the underlying disease process is essential for current and future studies on early detection, prevention, and treatment of underlying disease. Here, we review the current etiology‐based classification of DM and definitions of DM types in human medicine and discuss key points on the pathogenesis of each DM type and prediabetes. We then review current evidence for application of this etiology‐based classification scheme in dogs and cats. In dogs, we emphasize the lack of consistent evidence for autoimmune DM (Type 1) and the possible importance of other DM types such as DM associated with exocrine pancreatic disease. While most dogs are first examined because of DM in an insulin‐dependent state, early and accurate diagnosis of the underlying disease process could change the long‐term outcome and allow some degree of insulin independence. In cats, we review the appropriateness of using the umbrella term of Type 2 DM and differentiating it from DM secondary to other endocrine disease like hypersomatotropism. This differentiation could have crucial implications on treatment and prognosis. We also discuss the challenges in defining and diagnosing prediabetes in cats.

Basal glucosuria in cats

“…Internal quality control samples for all analytes were routinely run every day. To determine an upper reference limit, cats with suspected (glucose >7 mmol/L [126 mg/dl (Gilor, Niessen, Furrow, & DiBartola, ) and glucosuria [dipstick] and/or fructosamine >340 µmol/L) or treated diabetes mellitus (DM), and with diseases/treatments possibly effecting fractional glucose clearance such as hyperthyroidism (HT, thyroxine >45.57 nmol/L, da Silva Teixeira et al ), acute or chronic kidney disease ≥stage 2 (KD, creatinine >141.44 µmol/L (>1.6 mg/dl), urine specific gravity (USG <1.035, Brown, ) or current glucocorticoid treatment (Lowe, Graves, Campbell, & Schaeffer, ) were excluded. To assess associations between renal function and glucosuria, cats with CKD ≥stage 2 were further subclassified according to the International Renal Interest Society (IRIS) into stages 2–4 (Brown, ).…”

Diabetes mellitus in dogs

“…There have been several attempts to classify canine diabetes, but this remains very challenging since the disease is heterogeneous and it is also not clear whether the pathogenesis differs between or within breeds (Gilor and others 2016). One proposed classification scheme for canine diabetes is shown in Box 1.…”

Diagnóstico y tratamiento de la diabetes mellitus en perros

“…La DM se encuentra clasificada dentro de las enfermedades metabólicas, cuya característica principal es la hiperglucemia en plasma, causada por defectos en la secreción o acción de la insulina; por tal modo la hiperglucemia es consecuencia de que el organismo no puede regular la cantidad de glucosa en la sangre, debido a que el páncreas no produce insulina suficiente o las células de tejidos y órganos blanco; y no responden de manera normal a esta hormona (Gilor et al, 2016). La DM es una de las endocrinopatías más frecuentes en perros y gatos, puede llegar a ser mortal si no se proporciona a tiempo un tratamiento adecuado; se puede presentar en todas las razas de perros, pero existe mayor susceptibilidad en las razas: Australian terrier, Schnauzer Standard y miniatura, Samoyedo y Fox Terrier.…”

“…La raza Bóxer es la que presenta mayor resistencia a la DM; similar que en humanos, las hembras son más propensas a esta patología; superando a los machos en una proporción de 3:1. (Guptill et al, 2003;Kennedy et al, 2006;Gilor et al, 2016).…”

“…Por lo que al parecer existe una predisposición genética asociada al complejo de histocompatibilidad canino clase II (DLA= Dog Leukocyte Antigens) (Catchpole et al, 2005).  DM tipo II o no insulina dependiente: se presenta cuando el páncreas conserva parcialmente su actividad, pero los receptores de insulina no responden de manera adecuada al estímulo (Gilor et al, 2016). Este tipo de patología es la más común en humanos y aún hay mucha controversia de que exista el equivalente en perros.…”