Comparative Histological Study of the Kidney in the Domestic Dogs and Cats

The objective of the present study was to conduct a comparative histological of the renal anatomy in dogs and cats. A sample consisting of twenty healthy adult subjects (ten domestic cats and ten domestic dogs) was utilized for this investigation. The average weight of the local feline population was recorded at 2 ± 0.4 kg, whereas the local canine average weight was significantly higher at 20 ± 3 kg, with both species represented within the age range of one to three years. The histological attributes of the kidneys were examined post-slaughter. The structure of the nephron includes a renal corpuscle and various tubules-proximal straight and convoluted and distal straight and convoluted. Urine formation begins as fluid from the glomerular capsule enters the proximal tubule, which is lined by a simple cuboidal epithelium with a pronounced apical microvilli border. The thin tubule, a continuation of the proximal tubule, is encapsulated in simple squamous epithelium with spherical nuclei. Notably, the Bowman’s capsule serves as the convergence point for the glomeruli, comprising dense connective tissue. Comparative histological analysis identified that the urinary tubule linking to the glomerulus demonstrated greater clarity in feline tissues as opposed to canine tissues. Additionally, proximal tubule channels in cats appeared more dilated compared to those in dogs, and cats exhibited larger nuclei in both proximal and distal tubule cells. Periodic acid–Schiff staining revealed that feline renal tissues were more susceptible compared to their canine counterparts. Furthermore, cats displayed denser and more intensely red renal tissue and connective cells. Interestingly, islands of ascending branches of the loop of Henle were observed amid more densely arranged papillary ducts in feline kidneys, a structural feature that was notably absent in canines. The comparative study of the histology of the kidney in cats and dogs is important for several reasons, particularly in veterinary medicine, research, and clinical diagnostics. Studying kidney histology in cats and dogs provides insights into similar diseases in humans, aiding in comparative nephrology. Helps in the development of new diagnostic markers and treatments.