eng Rovedar Journal of Veterinary Physiology and Pathology 2821-0328 2025-12-29 4 4 74 84 10.58803/jvpp.v4i4.75 77 Emmanuel Vandi Tizhe 0 https://orcid.org/0000-0002-0361-1902 Pam Dachung Luka 1 https://orcid.org/0000-0002-6170-4242 Benshak John Audu 1 https://orcid.org/0000-0001-8770-8359 James Satvil Dalis 2 https://orcid.org/0000-0002-8333-1862 Arthur Obinna Oragwa 2 https://orcid.org/0000-0002-4873-2089 Asinamai Athliamai Bitrus 2 https://orcid.org/0000-0002-8649-4798 Ussa Delia Tizhe 3 Lucius Chidiebere Imoh 4 https://orcid.org/0000-0002-7368-2650 Anvou Rachel Dalyop 1 Victoria Isioma Ifende 1 Chidiebere Uchendu 5 https://orcid.org/0000-0002-8124-1118 Polycarp Tanko 0 https://orcid.org/0000-0003-1459-2564 Deborah Maigawu Buba 0 https://orcid.org/0000-0003-0910-7798 George Yilzem Gurumyen 0 https://orcid.org/0000-0001-6389-8573 Idris Ayodeji Azeez 6 https://orcid.org/0000-0001-5858-1395 Charibu Hurdison Dishon 7 https://orcid.org/0009-0004-1769-7040 Peace Ochai 7 Ikechukwu Onyebuchi Igbokwe 8 https://orcid.org/0000-0002-5039-4496 Department of Veterinary Pathology, Faculty of Veterinary Medicine, University of Jos, Jos, Plateau State, Nigeria National Veterinary Research Institute, Vom, Plateau State, Nigeria Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Jos, Jos, Plateau State, Nigeria Department of Veterinary Medicine, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Kaduna State, Nigeria Department of Chemical Pathology, Faculty of Basic Clinical Sciences, University of Jos, Jos, Plateau State, Nigeria Department of Veterinary Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Jos, Jos, Plateau State, Nigeria Department of Veterinary Anatomy, Faculty of Veterinary Medicine, University of Jos, Jos, Plateau State, Nigeria Faculty of Veterinary Medicine, University of Jos, P.M.B. 2028, Jos, Plateau State, Nigeria Department of Veterinary Pathology, Faculty of Veterinary Medicine, University of Maiduguri, Maiduguri, Borno State, Nigeria Introduction: Laboratory investigations are essential for diagnosing and managing diseases. The present study aimed to detect Rhizopus microsporus (R. microsporus) and Klebsiella pneumoniae (K. pneumoniae) in a Russian shepherd dog using molecular, gross, and histopathology methods to confirm the disease entity in the clinical setting following treatment failure. Case report: A 4-month-old female Russian shepherd dog weighing 16 kilograms was presented to the Veterinary Teaching Hospital, University of Jos, Nigeria, with signs of haematuria, melena, ascites, and anorexia. The dog exhibited severe icterus in its mucous membranes with ascites. Blood samples were collected for parasitological and haematological examinations. Haematological evaluations revealed mild leukopenia and a mild babesiosis, which was effectively treated before the dog died. Immediate therapy was started using imidocarb, ceftriaxone, furosemide, lactated Ringer’s solution, B-complex, iron dextran, and piroxicam. Despite initial therapy, the dog died five weeks after treatment. In post-mortem examination, samples from the lung, heart, liver, kidney, and spleen were collected and fixed in neutral buffered formalin 10% and prepared for histological evaluation. The non-formalinized samples of liver and lung were processed for both bacteriology and mycology assessments. To determine the presence of mycotoxins, a urine sample was obtained. Aflatoxin B1 was also detected in the urine at a concentration of 10,000 ng/mL. Generalized icterus, pulmonary congestion, cardiomegaly, splenomegaly, multifocal nodular lesions on the liver, severe intestinal haemorrhages, and ascites were the gross lesions observed. Rhizopus microsporus and K. pneumoniae were detected in microbial cultures of liver and lung samples. The present findings were further supported by PCR and gene sequencing. These strains were genetically related, clustering with Asian strains on the phylogenetic trees. Conclusion: The present study illustrated challenges in the clinical diagnosis of uncommon mixed microbial infections in veterinary practice, where laboratory diagnosis, after post-mortem examination, was essential in the diagnosis of aflatoxicosis along with systemic R. microsporus and K. pneumoniae infections, which caused nodular hepatopathy, toxic nephropathy, myocardial necrosis, and interstitial pneumonia. https://jvpp.rovedar.com/index.php/JVPP/article/view/75 Aflatoxicosis Dog Klebsiella pneumoniae Rhizopus microsporus Russian shepherd