Veterinary Immunology and Heartworm Diagnostics Exam Questions and Answers 2026 (118 Questions) | ELISA, Heartworm Testing, Dirofilaria immitis, FeLV/FIV & Immune Responses | Veterinary Medicine

This comprehensive veterinary revision guide contains 118 expertly verified exam-style questions and answers covering essential concepts in veterinary immunology, diagnostic immunology, and canine and feline heartworm disease. Designed for active recall and examination success, this resource integrates foundational immunological principles with clinically relevant diagnostic procedures frequently assessed in Veterinary Medicine, Veterinary Technology, and Veterinary Nursing curricula. The immunology section provides an in-depth review of innate and adaptive immunity, emphasizing the mechanisms that protect the host against infectious agents and maintain immune surveillance. Students will strengthen their understanding of inflammatory responses, phagocytosis, antigen recognition, antibody production, complement activation, cytokine signaling, immunologic tolerance, passive and active immunity, and the coordinated functions of monocytes, macrophages, neutrophils, natural killer cells, B-lymphocytes, T-lymphocytes, and helper T-cells. Comprehensive coverage is devoted to veterinary diagnostic immunology, including Enzyme-Linked Immunosorbent Assays (ELISA), Competitive ELISA (cELISA), latex agglutination, lateral flow immunoassays, immunodiffusion, fluorescent antibody testing (IFA), radioimmunoassays (RIA), molecular diagnostics, polymerase chain reaction (PCR), antibody titers, intradermal testing, and Coombs testing. The guide further explores test sensitivity and specificity, sample collection requirements, common analytical errors affecting diagnostic accuracy, and interpretation of positive and negative results encountered in clinical practice. A major focus of this review is canine and feline heartworm disease caused by Dirofilaria immitis. Students will gain a detailed understanding of heartworm epidemiology, life cycle stages, vector transmission by mosquitoes, definitive and intermediate hosts, occult infections, diagnostic limitations, antigen and microfilaria testing protocols, treatment planning, and prevention strategies. The document thoroughly explains heartworm prevention using macrocyclic lactones, annual testing recommendations, causes of preventive failure, microfilaria detection techniques, and evidence-based approaches to patient management. Advanced heartworm topics include pre-adulticide diagnostic evaluation, factors influencing treatment complications, melarsomine administration protocols, adjunct therapies, Wolbachia management, exercise restriction, treatment confirmation, and differences between canine and feline heartworm infections. Students will also review feline heartworm pathology and the unique diagnostic challenges associated with heartworm disease in cats. The content reflects principles described in leading veterinary textbooks and peer-reviewed scientific literature, including: • Tizard IR. Veterinary Immunology: An Introduction. 11th Edition. Elsevier. • American Heartworm Society. Current Canine Guidelines for the Prevention, Diagnosis, and Management of Heartworm Infection (Dirofilaria immitis). • Sykes JE. Canine and Feline Infectious Diseases. Elsevier. • Greene CE. Infectious Diseases of the Dog and Cat. 5th Edition. Elsevier. • Ettinger SJ, Feldman EC, Côté E. Textbook of Veterinary Internal Medicine. 9th Edition. Elsevier. • Thrall MA, Weiser G, Allison RW, Campbell TW. Veterinary Hematology and Clinical Chemistry. 3rd Edition. Wiley-Blackwell. Relevant Students: Veterinary Medicine students Veterinary Technology students Veterinary Nursing students Animal Health Technology students Pre-veterinary students Veterinary Clinical Pathology students Veterinary Immunology students Small Animal Internal Medicine students Veterinary Diagnostic Laboratory students Students studying parasitology and vector-borne diseases Students preparing for veterinary immunology examinations Candidates preparing for veterinary licensing and certification assessments Keywords: Veterinary Immunology, Heartworm Diagnostics, Veterinary Medicine Exam Questions, Veterinary Technology Study Guide, Veterinary Nursing Revision, ELISA, cELISA, Competitive ELISA, Coggins Test, Equine Infectious Anemia, Diagnostic Immunology, Innate Immunity, Adaptive Immunity, Humoral Immunity, Cell-Mediated Immunity, B-Lymphocytes, T-Lymphocytes, Natural Killer Cells, Monocytes, Macrophages, Neutrophils, Phagocytosis, Antigens, Antibodies, Complement System, Cytokines, Interferons, Immunologic Tolerance, Passive Immunity, Active Immunity, Adjuvants, Immunization, Immunoglobulins, IgA, IgD, IgE, IgG, IgM, Helper T Cells, Sensitivity, Specificity, Lateral Flow Immunoassay, Latex Agglutination, Immunodiffusion, Coombs Test, Radioimmunoassay, Fluorescent Antibody Test, IFA, PCR, Molecular Diagnostics, Antibody Titers, Intradermal Testing, Dirofilaria immitis, Canine Heartworm Disease, Feline Heartworm Disease, Heartworm Lifecycle, Microfilaria Testing, Modified Knott Test, Occult Heartworm Infection, Antigen Testing, Melarsomine, Macrocyclic Lactones, Ivermectin, Selamectin, Moxidectin, Milbemycin, Wolbachia, Heartworm Prevention, Mosquito Control, Veterinary Parasitology, Veterinary Internal Medicine, Veterinary Clinical Diagnostics, Veterinary Revision Notes