Poultry Diseases: Viral and Bacterial Pathogens, Classification, and Diagnostic Approaches

1. Introduction

Poultry production faces continuous threats from a diverse array of viral and bacterial pathogens that compromise animal welfare, reduce productivity, and impose significant economic burdens on the global food supply chain [1, 45]. The clinical manifestation of infectious disease in commercial flocks depends on pathogen virulence, host immune status, environmental conditions, and management practices [41, 53]. Accurate and rapid diagnosis is essential for implementing effective control measures, including biosecurity protocols, vaccination strategies, and antimicrobial stewardship programs [66, 81]. This article provides a comprehensive reference on the classification, pathogenesis, and diagnostic approaches for major viral and bacterial pathogens affecting poultry.

2. Viral Pathogens of Poultry

2.1 Orthomyxoviridae: Avian Influenza Virus

Avian influenza virus (AIV) is a segmented negative-sense RNA virus belonging to the family Orthomyxoviridae. The virus is classified into low pathogenicity (LPAI) and high pathogenicity (HPAI) subtypes based on the molecular characteristics of the hemagglutinin (HA) cleavage site and intravenous pathogenicity index in chickens [2, 3]. HPAI H5N1 clade 2.3.4.4b has caused widespread outbreaks in commercial and non-commercial flocks across multiple continents [3, 4, 58, 88]. The HA glycoprotein mediates receptor binding and membrane fusion, and specific amino acid motifs at the cleavage site determine systemic spread [5, 94]. The H9N2 subtype, although typically LPAI, has demonstrated increasing genetic diversity and reassortment potential, particularly in co-circulation with H5N1 strains [6, 7, 61, 62]. The NS1 protein of H5N6 has been shown to enhance virulence in ducks through a specific F161L substitution. Strain-specific responses to host factors such as solute carrier family 35 member A1 (SLC35A1) have been documented in chicken cells [8]. Surveillance of environmental samples has proven a sensitive alternative to individual bird sampling for monitoring H9N2 in vaccinated turkey flocks [9].

2.2 Paramyxoviridae: Newcastle Disease Virus

Newcastle disease virus (NDV), also known as avian orthoavulavirus 1, is a negative-sense RNA virus that causes respiratory, neurological, and enteric disease in poultry [45, 54]. The virus is classified into pathotypes based on virulence: lentogenic, mesogenic, and velogenic strains [10]. Genotype VII NDV strains have emerged as predominant virulent variants in many regions. Maternal antibody transfer from breeder flocks influences the susceptibility of offspring to NDV infection [11]. Novel vaccine strategies, including polymeric nanocarriers for DNA vaccine delivery and recombinant herpesvirus-vectored vaccines, have been developed to improve protective immunity [12, 84]. Computational studies have identified polyene macrolides as potential antiviral agents against NDV [10].

2.3 Coronaviridae: Infectious Bronchitis Virus

Infectious bronchitis virus (IBV) is a positive-sense RNA coronavirus that causes respiratory disease, nephritis, and reproductive tract damage in chickens [56, 76, 93]. Multiple genotypes, including GI-1, GI-16, and GI-24, have been identified in commercial poultry populations. The virus induces inflammatory responses through activation of p38/MAPK signaling and NLRP3/caspase-1 inflammasomes via sphingosine-1-phosphate receptor 1. mRNA-LNP vaccines have been rationally designed to elicit protective immunity against IBV. Lactoferrin has demonstrated antiviral effects against IBV, associated with alterations in the gastrointestinal microbiome.

2.4 Birnaviridae: Infectious Bursal Disease Virus

Infectious bursal disease virus (IBDV) is a double-stranded RNA virus that targets B lymphocytes in the bursa of Fabricius, causing immunosuppression [11, 13, 37, 49]. The VP2 capsid protein is the primary antigenic determinant, and amino acid insertions in the PHI loop can modify antigenicity and abrogate propagation in B cells. Nano-adjuvants have been developed to enhance the immunogenicity and safety of IBDV vaccines [13]. A recombinant chimeric NDV-vectored vaccine has been constructed to provide triple protection against NDV, IBDV, and H9N2 AIV.

2.5 Herpesviridae: Marek's Disease Virus and Infectious Laryngotracheitis Virus

Marek's disease virus (MDV) is an alphaherpesvirus that causes T-cell lymphoma and immunosuppression in chickens. Multiplex PCR methods have been developed for differential diagnosis of clinical cases and vaccine immunization. Infectious laryngotracheitis virus (ILTV) is another alphaherpesvirus that causes severe respiratory disease characterized by dyspnea and hemorrhagic tracheitis [14, 68]. Subclinical circulation of recombinant ILTV has been documented in vaccinated commercial layers. Multi-epitope vaccines based on envelope glycoproteins have been designed using immunoinformatics approaches [14].

2.6 Adenoviridae: Fowl Adenovirus and Egg Drop Syndrome Virus

Fowl adenoviruses (FAdV) are non-enveloped double-stranded DNA viruses classified into multiple serotypes [15, 16, 57, 83, 91]. FAdV-4 causes inclusion body hepatitis and hydropericardium syndrome, with residue 188 of the hexon protein governing pathogenicity through PINK1/Parkin-mediated mitophagy [15]. FAdV-11 pathogenicity is determined by a conserved deletion of two consecutive glycine residues in the 100K protein. Trivalent vaccines (serotype 4/8b/11) provide efficient protection with long duration of immunity [16]. Egg drop syndrome virus (EDSV) is an atadenovirus that causes decreased egg production and shell quality.

2.7 Reoviridae: Avian Reovirus and Duck Orthoreovirus

Avian reoviruses (ARV) are non-enveloped double-stranded RNA viruses that cause viral arthritis, tenosynovitis, and enteric disease [42, 63, 75, 90]. Comparative analysis of genotypes I to V has revealed differences in viral biological characteristics and pathogenicity. Goose-origin orthoreoviruses have demonstrated interferon suppression activity. Loop-mediated isothermal amplification (LAMP) assays have been developed for specific and quantitative detection of duck variant orthoreovirus.

2.8 Other Viral Pathogens

Duck hepatitis A virus (DHAV) is a picornavirus that causes acute hepatitis in ducklings, with complete genome sequencing revealing evolutionary dynamics in Egyptian duck farms [17]. Duck plague virus (DPV), an alphaherpesvirus, causes hemorrhagic disease in ducks and geese [18, 40, 77, 86, 96]. The US2 protein of DPV promotes p62-mediated autophagic degradation of RIG-I to suppress antiviral signaling. Chicken infectious anemia virus (CIAV) is a gyrovirus that causes immunosuppression and anemia in young chickens. Avian leukosis virus subgroup J (ALV-J) is a retrovirus that causes myeloid leukosis and immunosuppression [19, 69]. Avian metapneumovirus (aMPV) subtypes A and B cause turkey rhinotracheitis and swollen head syndrome in chickens [60, 87]. Chicken astrovirus (CAstV) causes enteric disease and white chick syndrome [20]. Duck astrovirus (DAstV) has been isolated from domestic ducklings with enteric disease. Duck Tembusu virus (DTMUV) is a flavivirus that causes egg drop and neurological signs in ducks.

3. Bacterial Pathogens of Poultry

3.1 Enterobacteriaceae: Escherichia coli and Salmonella

Avian pathogenic Escherichia coli (APEC) causes colibacillosis, a complex syndrome including airsacculitis, pericarditis, and septicemia [6, 80, 100]. Direct interaction between APEC and H9N2 AIV promotes bacterial adhesion during co-infections [6]. Bacterial biomimetic vesicles displaying HA1 protein have been constructed for vaccine development. Salmonella enterica serovars, including Salmonella Pullorum and Salmonella Kentucky, cause pullorum disease, fowl typhoid, and paratyphoid infections [21, 79, 112, 113]. Phage therapy has been explored as a novel strategy to combat drug-resistant Salmonella Pullorum infection. Genomic characterization of mcr-1.1-positive Salmonella Kentucky ST198 has revealed links to broiler poultry [21].

3.2 Pasteurellaceae: Pasteurella multocida, Avibacterium paragallinarum, and Gallibacterium anatis

Pasteurella multocida causes fowl cholera, a septicemic disease affecting chickens, turkeys, and waterfowl [1]. Avibacterium paragallinarum causes infectious coryza, an upper respiratory tract infection characterized by facial edema and nasal discharge [1]. Gallibacterium anatis is associated with salpingitis and peritonitis in laying hens [1].

3.3 Clostridiaceae: Clostridium perfringens

Clostridium perfringens type A and type C cause necrotic enteritis in broiler chickens, a disease characterized by intestinal necrosis and high mortality [22, 23, 24]. The intestinal microbiome plays a critical role in disease pathogenesis, and treatment alternatives including bacteriophages and probiotics have been investigated [23, 24]. Cystic enteropathy has been retrospectively analyzed in Alabama broilers [22].

3.4 Mycoplasmataceae: Mycoplasma gallisepticum, Mycoplasma synoviae, and Mycoplasma meleagridis

Mycoplasma gallisepticum causes chronic respiratory disease in chickens and infectious sinusitis in turkeys [1]. Mycoplasma synoviae causes infectious synovitis and eggshell apex abnormalities [1]. Mycoplasma meleagridis is associated with airsacculitis and leg deformities in turkeys [1].

3.5 Other Bacterial Pathogens

Campylobacter jejuni and Campylobacter coli are zoonotic pathogens that colonize the poultry gastrointestinal tract. Bacteriophages have been investigated for mitigating Campylobacter contamination across the poultry food chain. Staphylococcus aureus causes bumblefoot and osteomyelitis in broilers [1]. Streptococcus zooepidemicus is an emerging pathogen associated with septicemia and mortality in poultry [1]. Borrelia anserina causes avian spirochetosis, transmitted by Argas persicus ticks [1]. Erysipelothrix rhusiopathiae causes erysipelas in turkeys and other birds [1]. Listeria monocytogenes, although primarily a ruminant pathogen, can be isolated from poultry products [112, 113].

4. Classification of Poultry Pathogens

4.1 Viral Classification

Viruses are classified according to the Baltimore system based on genome type and replication strategy. Poultry viruses include double-stranded DNA viruses (Adenoviridae, Herpesviridae), single-stranded DNA viruses (Circoviridae, Parvoviridae), double-stranded RNA viruses (Reoviridae, Birnaviridae), positive-sense single-stranded RNA viruses (Coronaviridae, Picornaviridae, Flaviviridae), and negative-sense single-stranded RNA viruses (Orthomyxoviridae, Paramyxoviridae). Genotypic classification based on genetic sequencing has become the standard for epidemiological surveillance and vaccine matching [17, 25, 4, 54, 58, 76, 91].

4.2 Bacterial Classification

Bacterial pathogens are classified by Gram stain reaction, morphology, metabolic characteristics, and genomic analysis. Gram-negative pathogens include Escherichia coli, Salmonella, Pasteurella, Avibacterium, Gallibacterium, and Campylobacter. Gram-positive pathogens include Clostridium, Staphylococcus, Streptococcus, and Erysipelothrix. Bacteria lacking cell walls, such as Mycoplasma species, require specialized culture media and molecular detection methods [1].

5. Diagnostic Approaches

5.1 Clinical and Pathological Examination

Clinical signs vary by pathogen and organ system affected. Respiratory signs (coughing, sneezing, dyspnea) are common in AIV, NDV, IBV, ILTV, and aMPV infections [41, 60, 68]. Enteric signs (diarrhea, decreased feed intake) are associated with CAstV, DAstV, rotavirus, and Clostridium perfringens [22, 23, 44, 98]. Neurological signs (torticollis, ataxia, paralysis) occur in NDV, DTMUV, and MDV infections [45, 92]. Postmortem examination reveals characteristic lesions including hemorrhagic tracheitis (ILTV), bursal atrophy (IBDV), hepatic necrosis (FAdV, DHAV), and intestinal necrosis (Clostridium perfringens) [15, 17, 22, 49].

5.2 Molecular Diagnostics

Polymerase chain reaction (PCR) and real-time PCR are the primary molecular methods for pathogen detection and quantification [47, 59, 70, 89, 92]. Multiplex PCR allows simultaneous detection of multiple pathogens in a single reaction. Reverse transcription PCR (RT-PCR) is required for RNA virus detection [60, 92]. Loop-mediated isothermal amplification (LAMP) provides rapid, field-deployable detection without thermal cycling equipment. Recombinase-aided amplification (RAA) combined with Cas12a detection technology enables sensitive and specific pathogen identification. High-throughput sequencing (metagenomics) facilitates pathogen discovery and genomic surveillance [17, 25, 4, 100]. Whole-genome sequencing provides high-resolution epidemiological data for outbreak investigations [17, 4, 58, 88].

5.3 Serological Diagnostics

Enzyme-linked immunosorbent assay (ELISA) is widely used for antibody detection and quantification in flock surveillance [11, 1, 60, 87]. Hemagglutination inhibition (HI) and virus neutralization (VN) tests are used for subtype-specific antibody detection [11, 9, 1]. Agar gel immunodiffusion (AGID) is used for detecting antibodies against MDV and ILTV [1].

5.4 Microbiological Culture and Isolation

Virus isolation in embryonated chicken eggs or cell culture remains the gold standard for many viral pathogens [1]. Bacterial culture on selective and differential media is essential for isolation and identification of bacterial pathogens [1]. Antimicrobial susceptibility testing guides therapeutic decisions.

5.5 Advanced Diagnostic Technologies

Biosensors based on graphene, surface-enhanced Raman scattering (SERS), and electrochemical platforms enable rapid pathogen detection [107, 136, 145]. Aptamer-based technologies provide alternative recognition elements for pathogen capture and detection. Metabolomic profiling, including serum lysoPC/PC depletion, has been explored as a biomarker for avian reoviral infection.

graph TD
 A[Clinical Signs and History] --> B{Initial Assessment}
 B --> C[Postmortem Examination]
 B --> D[Sample Collection]
 D --> E[Fresh Tissues, Swabs, Blood, Feces]
 E --> F{Diagnostic Pathway}
 F --> G[Molecular Diagnostics]
 F --> H[Serological Diagnostics]
 F --> I[Microbiological Culture]
 F --> J[Advanced Technologies]
 G --> K[PCR / RT-PCR / Real-Time PCR]
 G --> L[LAMP / RAA-Cas12a]
 G --> M[High-Throughput Sequencing]
 H --> N[ELISA / HI / VN / AGID]
 I --> O[Bacterial Culture and Isolation]
 I --> P[Virus Isolation in Eggs or Cell Culture]
 J --> Q[Biosensors / SERS / Aptamers]
 J --> R[Metabolomics / Proteomics]
 K --> S[Pathogen Identification and Quantification]
 L --> S
 M --> S
 N --> S
 O --> S
 P --> S
 Q --> S
 R --> S
 S --> T[Genotyping / Serotyping / Antimicrobial Susceptibility]
 T --> U[Epidemiological Analysis and Control Measures]

6. Conclusion

The diagnosis and control of poultry diseases require a multidisciplinary approach integrating clinical examination, molecular diagnostics, serology, and microbiology. The emergence of antimicrobial resistance in bacterial pathogens and the continuous evolution of viral pathogens necessitate ongoing surveillance and vaccine development [66, 101, 102, 103, 104, 109]. Advances in genomic technologies and bioinformatics have revolutionized pathogen detection and characterization, enabling rapid response to disease outbreaks and informing control strategies [17, 25, 4, 58, 88, 100, 114, 122, 133, 139, 143, 148].

References

[1] Benedict SR, Gallardo RA, Liebross B et al. Biosecurity assessment and seroprevalence of relevant poultry diseases in Saint Kitts commercial poultry premises. Trop Anim Health Prod. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42207315/

[2] Chen T, Huang Q, Chen X et al. Trimeric hemagglutinin vaccine provides chickens complete protection against lethal H5 subtype avian influenza virus from clade 2.3.4.4b. Emerg Microbes Infect. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42269026/

[3] Powell MR. Temporal Analysis of Highly Pathogenic Avian Influenza H5N1 in Commercial and Non-Commercial Flocks in the United States; 2022-2025. Risk Anal. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42227147/

[5] Chen X, Dong J, Zhao C et al. Dominant HA motif 131/132-NT shapes the phenotype of avian H9N2 influenza virus by modulating agglutination property, receptor specificity and infectivity in animals. Virol Sin. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42288138/

[6] Li Y, Xue Y, Quan Y et al. Direct interaction between avian pathogenic Escherichia coli and H9N2 avian influenza virus promotes bacterial adhesion during their infections. Microbiol Spectr. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42294695/

[7] Li J, Zhang C, Li R et al. A new clade of H9N2 avian influenza virus circulating in Laos. Emerg Microbes Infect. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42243068/

[8] Liu H, Cruvinel JM, Warren WC et al. Strain-specific responses of avian influenza virus to disruption of solute carrier family 35 member A1 (SLC35A1) in chicken cells. Poult Sci. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42241751/

[9] Kalvelage L, Casteel M, Hartmann M et al. Environmental samples, a sensitive and practical alternative to individual bird sampling in the surveillance of H9N2 vaccinated turkey flocks. J Gen Virol. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42262844/

[10] Mukhametkaliyev A, Bogoyavlenskiy A, Alexyuk P et al. Antiviral Activity of Polyene Macrolides Against Newcastle Disease Virus: Computational and Experimental Insights. Molecules. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42280215/

[11] Wegner M, Gesek M. The influence of Ross 308 breeder flock age on serum Newcastle Disease Virus and Infectious Bursal Disease Virus antibody levels and their transfer to offspring. Pol J Vet Sci. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42299112/

[12] Khattab AH, Bayoumi M, Eldin ZE et al. Comparative Evaluation of Polymeric Nanocarriers for DNA Vaccine Delivery Against Avian Orthoavulavirus 1 in Chickens. Viruses. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42198782/

[13] Asif TA, Ji P, Qiao X et al. Nano-adjuvants enhance the immunogenicity and safety of infectious bursal disease virus vaccines: a comprehensive review. Front Immunol. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42220545/

[14] Parisa J, Maryam M, Narjes NG et al. Development of an Effective Multiepitope Vaccine Against Infectious Laryngotracheitis Virus Based on Envelope Glycoproteins by Immunoinformatics Approaches. Arch Razi Inst. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/42226991/

[15] Wang B, Qiao Q, Yang P et al. Residue 188 of the Hexon protein governs FAdV-4 pathogenicity by activating PINK1/Parkin-mediated mitophagy. Vet Res. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42288922/

[16] Park DH, Min KC, Kim NR et al. Trivalent fowl adenovirus vaccine (serotype-4/8b/11) provides efficient protection with long duration of immunity. J Vet Sci. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42225601/

[17] Yehia N, AbdelSabour MA, Said D et al. Complete genome sequencing and evolutionary analyses of duck hepatitis a viruses in Egyptian duck farms. BMC Vet Res. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42249479/

[18] Yang Q, Yu H, Ai L et al. Deletion of the N-terminal 400 amino acids of DPV pUL36 attenuated virulence and conferred effective protection against virulent challenge. Poult Sci. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42214186/

[19] Chen Y, Zheng Y, Chen R et al. A recombinant baculovirus expressing multi-epitopes elicits protective immunity against ALV-J infection in chickens. Vet Microbiol. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42208336/

[20] Yahia N, Mahmoud SH, Abdelhalim A et al. Maternal antibody-mediated protection against chicken astrovirus: efficacy of novel inactivated vaccine. Vet Res Commun. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42301581/

[21] Carrasco Muñoz M, Pérez de Vargas A, Alhebshi M et al. Genomic characterization of mcr-1.1-positive Salmonella Kentucky ST198 from a captive Asian houbara bustard reveals links to broiler poultry in the United Arab Emirates. Front Vet Sci. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42205805/

[22] Lockyear O, Alvarez-Narvaez S, Conrad S et al. A retrospective analysis of cystic enteropathy in Alabama broilers. Avian Pathol. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42210854/

[23] Cagirgan OY, Korkmaz S, Diker KS. Intestinal microbiome in necrotic enteritis infection of broiler and comparison of treatment alternatives. Trop Anim Health Prod. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42207344/

[24] Manjunaha V, Justice-Alucho CH, Lumpkins BS et al. Combined effect of black cumin seeds and bacteriophage in mitigating necrotic enteritis in broiler chickens. J Appl Microbiol. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42202769/

[25] Lu X, Li M, Xu Q et al. Genomic surveillance and evolution of co-circulating goose parvovirus and waterfowl circovirus in China. Vet Res. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42231473/

[26] Dénes L, Schwarz L, Brunthaler R et al. Characterization of Pestivirus scrofae infection in the tissues of a persistently infected boar. Porcine Health Manag. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42304515/

[27] Huang Q, Yang F, Wu S et al. Molecular cloning and antiviral function analysis of pigeon interferon lambda(piIFN-λ). Poult Sci. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42302606/

[28] Wang M, Gao Y, Zhang Y et al. A novel oral vaccine strategy using a plasmid with CAG promoter-driven alphavirus RdRp for Co-expression of NA epitope and adjuvant in attenuated Salmonella boosts immune responses against H9N2 in mice. Microb Pathog. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42297223/

[29] Gu Y, Duan H, Ji C et al. Development and Immune Efficacy Evaluation of Two Live Triple-Gene-Deleted Vaccine Candidates Against Bovine Herpesvirus Type 1. Animals (Basel). 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42278041/

[30] Chavoix C, Pain-Deloizy C, Massin P et al. Pathogenicity and immune response of turkey A(H1N2) influenza virus of swine-origin on turkeys and mice. Vet Res. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42237404/

[31] Zahra B, Behzad H, Morteza T et al. Multi-epitope HA Vaccine Confers Cross-protective Immunity to H5N8 and H9N2. Arch Razi Inst. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/42226989/

[32] Cao Y, Zhang J, Yoo D et al. Swine TRIM25 inhibits vesicular stomatitis virus replication by activation of type I IFN signaling pathway and binding vRNA. J Vet Sci. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42225600/

[33] Li F, Ren C, Liu W et al. Divergent immunometabolic landscapes of chicken and swan goose identify SERPINF2 as a novel restriction factor for influenza A virus. Virol J. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42216012/

[34] Gupta N, Smielewska A, Felix Drexler J et al. Avian Influenza in Humans: Virology, Transmission, and Clinical Priorities. QJM. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42213088/

[35] Huang M, Wu L, Wang Y et al. Harnessing T4 phage-based platform for efficient design of ready-to-use multiepitope vaccines. Antiviral Res. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42208905/

[36] Chen Y, Pan W, Miao X et al. Molecular arms races at the virus-host splicing interface and their pathogenic implications. Front Microbiol. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42205581/

Disclaimer: This article is for educational and informational purposes only. It is not intended to substitute for professional veterinary advice, diagnosis, treatment, or regulatory guidance. Always consult a licensed veterinarian or qualified specialist regarding animal health, disease diagnosis, and therapeutic decisions.