Macroanatomical, Histological, Histochemical and Ultrastructural Characterisation of the Kidney in the Aksaray Malakli Dog: First Comprehensive Renal Morphological Study of the Breed.

backgroundThe Aksaray Malaklı dog is a native Turkish breed indigenous to the Central Anatolian region, yet its renal morphology has not been comprehensively characterised.

objectiveThis study aimed to investigate the macroanatomical, histological, histochemical and scanning electron microscopic (SEM) structure of the kidney in the Aksaray Malaklı dog for the first time.

methodsThis study aimed to investigate the macroanatomical, histological, histochemical and SEM structure of the kidney in the Aksaray Malaklı dog for the first time. Eight adult Aksaray Malaklı dogs (four male, four female) were used as material. Kidneys were examined macroanatomically following euthanasia and fixation. Tissue samples were processed for histological (HE), histochemical (Alcian Blue at pH 1.0 and 2.5, PAS, and Gordon Sweet staining) and SEM analyses.

resultsMacroanatomically, the kidneys were bilaterally positioned in the regio lumbalis, with the right kidney located more cranially. Histologically, the kidney was enclosed by a fibrous capsule; the cortex contained renal corpuscles, proximal and distal convoluted tubules, and medullary rays, while the medullary contained straight tubules, collecting ducts and capillaries. Podocytes, macula densa cells, juxtaglomerular cells and mesangial cells were clearly identified. Histochemically, no reaction was detected with Alcian Blue at pH 1.0 or pH 2.5; PAS staining yielded positive reactions in Bowman's capsule, proximal tubule basal portions, and vascular endothelium. Gordon Sweet staining revealed reticular fibres around the capsule, blood vessels, renal corpuscles and tubules; notably, an exceptionally dense reticular network was identified in the cortical zone where renal corpuscles were abundant but tubules were sparse a finding not previously reported in the literature. SEM examination demonstrated the three-dimensional architecture of renal corpuscles and tubular structures.

conclusionsThis study provides the first comprehensive morphological dataset for the Aksaray Malaklı dog kidney. The breed-specific dense reticular fibre network represents a novel finding. SEM proved to be a valuable tool for three-dimensional visualisation of renal architecture. These findings are expected to contribute to the differential diagnosis of urinary tract pathologies in dogs and to comparative studies on renal morphology in Carnivora.