Dr. Munajid Al-Tamimi (Diploma in Obstetrics and Reproductive Diseases)
13/9/2026
Determining the animal source of meat is a crucial aspect of food control, playing a vital role in detecting commercial fraud, protecting consumers, and verifying the accuracy of product labeling. This article briefly reviews the methods used to distinguish between beef, pork, and donkey meat, ranging from visual and sensory inspection to DNA-based molecular tests. While characteristics such as color, texture, fat distribution, and muscle fibers serve as preliminary indicators, they are insufficient to conclusively identify the animal species; definitive diagnosis requires appropriate laboratory methods, most notably PCR.
Introduction
Meat adulteration—specifically the substitution of one animal species for another—is an issue that impacts food safety and consumer rights, in addition to having economic and religious implications. Identifying the animal source becomes increasingly difficult with minced, processed, and cooked meats, as these products lose many of their distinctive anatomical and visual characteristics. Consequently, modern food control protocols rely on a combination of preliminary inspection and laboratory testing, avoiding definitive conclusions based solely on external appearance.
Visual and Sensory Inspection
Preliminary inspection involves observing muscle color, fat distribution, the nature of muscle fibers, texture, and odor. While differences between meat types may be apparent, they are not consistent enough to allow for definitive species identification. Color, for instance, is influenced by myoglobin content, the animal’s age, muscle type, the extent of oxygen exposure, and storage duration and conditions. Similarly, fat content, color, and distribution vary based on the animal’s breed, age, diet, and body condition. Therefore, asserting that a specific color or texture necessarily indicates the meat is from cattle, pigs, or donkeys is scientifically inaccurate. Such characteristics serve only to raise suspicion and guide further examination, rather than conclusively identifying the species.
Laboratory Analysis
When the substitution of one meat type for another is suspected, laboratory tests offer greater reliability. Techniques based on proteins and immunoassays, as well as DNA-based molecular methods, are employed for this purpose. DNA analysis methods are distinguished by their ability to identify animal species with high specificity; furthermore, DNA is relatively more stable than certain proteins in processed products.
PCR Technology
Polymerase Chain Reaction (PCR) technology is a vital tool for verifying the animal source of meat by amplifying specific DNA segments unique to the target species. Species-specific PCR can be used to detect a particular species, whereas multiplex PCR allows for the simultaneous detection of multiple species in a single test. Real-time PCR (qPCR) is also utilized for the sensitive and specific detection of animal DNA. Other methods—such as PCR-RFLP, DNA sequencing, and DNA barcoding—are also available; the appropriate technique is selected based on the sample type, the objective of the analysis, and available laboratory capabilities. The Importance of Identifying Meat Types
Verifying the animal source of meat helps combat food fraud, protects consumers, enhances health and veterinary oversight, and ensures the accuracy of food labeling; it is also crucial for products subject to specific religious or legal restrictions. For consumers, the best preventive measure is to purchase meat from trusted sources and shops subject to health and veterinary inspections, while avoiding products of unknown origin. One should not rely solely on color, odor, or the appearance of fat to determine the animal species, particularly with ground or processed meats.
Conclusion
Visual and sensory inspections can provide preliminary indicators that alert inspectors or veterinarians to potential discrepancies in the nature of the meat, but they do not constitute definitive proof of the animal species. When reliable identification of the animal source is required, appropriate laboratory tests should be employed. Molecular techniques—specifically PCR and Real-Time PCR—are among the most important tools for verifying meat authenticity and detecting substitution or fraud.
Public Awareness Message
Meat type cannot be conclusively determined by color or appearance alone. Purchase meat from trusted sources; if there is any suspicion, laboratory testing is the most accurate method for verifying the animal species.
References
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Why can’t we get rid of these cheeses?
Dr. Milad Ibrahim Oraibi
31/8/2026
Initially, when the virus enters the poultry house and is inhaled through the nose, it attacks ciliated epithelial cells, leading to their death and damage. This results in the infiltration of many heterophile cells into the trachea due to severe inflammation. These cells lack the enzyme myeloperoxidase, which breaks down proteins as neutrophils do in mammals. Consequently, the dead cells do not decompose into mucus but rather clump together into a thick, coagulated tissue. Fibrin, along with other inflammatory fluids rich in fibrinogens from damaged blood vessels, transforms into a network of fibrin fibers composed of dead cells, heterophiles, and any secondary viruses and bacteria present in the tracheal lumen. This material then gradually dries and hardens within the trachea due to the inhaled and exhaled air. Then it turns into a yellow substance with a gelatinous consistency, and then into a strong, curd-like substance that resembles cheese in appearance.
The important thing in the process is that the heterophile cells in poultry lack strong enzymes for breakdown such as (MPO and Elastase). These enzymes lead to the breakdown of dead cells and their breakdown with damaged tissues into a final product called (liquid pus), as in mammals. The absence of this mechanism will lead to the retention of dead cells with heterophile cells, which, if they turn into a liquid form, will adhere strongly to each other, which will be the caseous mass (liquefactive necrosis failure).
There is an important point: when the virus enters the epithelial cells and the endothelial cells, a strong immune response will occur, and pro-inflammatory cytokines will be secreted, namely IL, IB, IL6, and TNF-a. Because of this process, vascular permeability will increase, and this in turn will allow large quantities of proteins and high molecular weight plasma to pass through, the most important of which is fibrinogen.
When fibrinogen comes into contact with factors such as tissue factor released from dead and damaged epithelial cells, coagulation, clotting, or hardening will occur, and fibrin will be converted into insoluble fibrin meshwork, which will trap the damaged and destroyed cells inside.
Then this network turns into (coagulation and caseous necrosis) where there is a lack of blood supply to the damaged and destroyed area caused by the blockage of microscopic capillaries by (microthrombosis) and eventually (coagulative necrosis) will occur.
After the rapid passage of air through inhalation and exhalation, and due to accelerated breathing (hyperventilating) resulting from a lack of oxygen in the body, drying of the formed materials will occur and form (fibrinonecrotic mass), then it gradually turns from a soft mucous consistency to a solid, cohesive consistency resembling cheese called (caseous plug) and takes the shape of a tracheal cast.
The cause of chicken death is:
１- Mechanics due to respiratory tract obstruction
２- Lack of oxygen and the heart’s inability to work
３- Blood poisoning caused by gas retention and bacterial contamination
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https://drive.google.com/file/d/13pTWuTHaNzUkYETBfmPwH1Fbtx5E3C5X/view?usp=drive_link
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Dr. Nahlan Juwair Hassan Al-Samarrai
10-6-2026
Equine piroplasmosis is one of the most important tick-borne parasitic diseases in horses, caused by two main parasites: Babesia caballi and Theileria equi. However, many older references refer to the second parasite as Babesia equi, leading some to ask: Did Babesia become Theileria?
The answer is no. The parasite did not biologically change from one species to another. Rather, its scientific classification changed as a result of advancements in knowledge and the tools used to study parasites.
When the parasite was first discovered, its classification was primarily based on its microscopic appearance and the life cycle known at the time. Due to its similarity to other Babesia species within red blood cells, it was named Babesia equi. However, this classification was based on limited information compared to what is available today. With the advent of molecular biology techniques and gene sequencing, scientists began to study the evolutionary relationships between parasites with greater precision. Studies of the 18S rRNA gene showed that Babesia equi is more closely related to the genus Theileria than to the genus Babesia. These studies also revealed that the parasite exhibits a schizogony stage of asexual reproduction in mononuclear cells, a characteristic unique to Theileria and absent in true Babesia.
Based on this molecular and biological evidence, the parasite was officially reclassified as Theileria equi. Babesia caballi, however, remained within the genus Babesia because its genetic and biological characteristics were consistent with this classification.
This case clearly illustrates the evolution of taxonomy; with advancements in technology, reliance on genetic relationships has become more important than reliance on morphological similarity alone. This is why some older books and articles still use the name Babesia equi, while more recent references use the correct name, Theileria equi. In practice, both Babesia caballi and Theileria equi still cause equine piroplasmosis, but understanding the differences between them is crucial for epidemiological and diagnostic studies and for interpreting the results of recent research.
The story of Babesia equi’s transition to Theileria equi is not simply a story of one parasite changing from one species to another, but rather a story of evolution in scientific knowledge. Modern molecular evidence has led to a revision of the classification to reflect the true evolutionary relationship of this parasite.
Note: The name Babesia equi is still common in older veterinary literature, so when reviewing studies published before the 1990s or early 2000s, you may find both names used to refer to the same parasite.
References
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Airborne Aspergillus spp. Between Poultry Health and One Health Risk
Nahlan Jwair Hassan, DVM, Iraq
19-5-2025
Abstract
Aspergillosis remains one of the most significant airborne fungal diseases affecting both human and animal health. Aspergillus fumigatus, a ubiquitous environmental mold, becomes pathogenic when airborne conidia accumulate in enclosed environments and host susceptibility increases. In human healthcare settings, outbreaks have been strongly associated with environmental disturbances such as construction and inadequate air filtration. A parallel risk exists in poultry hatcheries, where elevated temperature, humidity, organic dust, and hatchery fluff create optimal conditions for fungal amplification. This paper reviews current evidence on airborne fungal contamination in hatcheries, evaluates environmental monitoring strategies (air sampling, settle plates, surface swabs, fluff analysis), and proposes hatchery environmental testing as a structured biosecurity certification requirement. Integrating environmental fungal surveillance into hatchery quality assurance programs is essential not only for chick viability and farm performance but also within a broader One Health framework due to increasing concerns regarding azole-resistant A. fumigatus strains.
Keywords: Aspergillosis, hatchery hygiene, airborne fungi, biosecurity, azole resistance, One Health
Introduction
Aspergillosis is a globally distributed fungal disease caused predominantly by Aspergillus fumigatus. The organism is naturally present in soil, organic debris, dust, and decaying vegetation. Infection occurs primarily through inhalation of airborne conidia. While healthy hosts may eliminate spores effectively, disease emerges when spore burden increases or host immunity declines.
In human medicine, invasive aspergillosis is particularly severe in immunocompromised individuals, including transplant recipients and patients in intensive care units. Environmental disturbances such as hospital construction have repeatedly been linked to airborne fungal outbreaks, emphasizing the critical role of environmental monitoring and HEPA filtration systems.
A comparable environmental dynamic exists in poultry hatcheries. High incubation temperatures (37–38°C), elevated humidity, organic dust accumulation, eggshell debris, and hatchery fluff provide an ideal substrate for fungal growth. Consequently, hatcheries may function as amplification hubs for airborne Aspergillus spores, potentially leading to early chick mortality, brooder pneumonia, and farm-level dissemination.
Environmental Ecology of Aspergillus in Hatcheries
Hatcheries present a microclimate conducive to fungal proliferation due to:
• Warm incubation temperatures
• Relative humidity exceeding 55–65%
• Accumulation of organic material (shell fragments, membranes, fluff)
• Recycled air systems with inadequate filtration
• Inconsistent sanitation between hatch cycles
Studies have demonstrated that hatchery fluff can harbor significant concentrations of fungal conidia, acting as a mechanical vehicle for dissemination into chick boxes and transport crates. Unlike bacterial contamination, fungal spores may remain airborne for prolonged periods, increasing inhalational exposure during chick handling and placement.
Importantly, the mere presence of Aspergillus does not equate to clinical disease. Disease development depends on:
• Spore concentration (CFU/m³)
• Exposure duration
• Ventilation efficiency (air changes per hour, ACH)
• Chick immune maturity
• Stressors such as transport and temperature fluctuation
Environmental Monitoring Strategies
Routine cleaning alone does not guarantee microbial safety. Objective environmental measurement is necessary.
1. Air Sampling: Active air samplers quantify fungal burden (CFU/m³). Alert and action thresholds should be predefined within hatchery quality management systems.
2. Settle Plates: Passive sedimentation plates provide trend monitoring of airborne contamination. Though semi-quantitative, they are cost-effective and useful for routine surveillance.
3. Surface Swabs: Swabbing incubator trays, ventilation ducts, and hatch baskets helps identify persistent contamination reservoirs.
4. Fluff Sampling: Fluff analysis has been proposed as an indirect indicator of airborne fungal load within hatch cabinets.
Integration of these methods allows for environmental trend analysis rather than reactive investigation following mortality events.
Disinfection and Engineering Controls
Environmental control requires a combined engineering and sanitation approach:
• HEPA or high-efficiency pre-filtration systems
• Controlled positive pressure gradients
• Adequate air exchange rates
• Moisture control
• Routine deep sanitation between cycles
Traditional fumigation with formaldehyde remains effective but raises occupational safety and regulatory concerns. Alternative technologies such as vaporized hydrogen peroxide, UV-C irradiation, and ozone treatment require further comparative validation in commercial hatchery settings.
One Health Considerations and Azole Resistance
Increasing global concern surrounds azole-resistant A. fumigatus, potentially linked to agricultural azole fungicide use. Poultry production environments may serve as ecological niches for resistant strains. While direct transmission pathways remain under investigation, environmental containment strategies align with broader antimicrobial resistance mitigation efforts.
Therefore, hatchery environmental monitoring extends beyond flock health—it intersects with public health risk reduction.
Economic and Production Impact
Failure to control airborne fungal contamination may result in:
• Increased early chick mortality
• Reduced growth performance
• Higher culling rates
• Increased antimicrobial usage
• Reputational and certification risks
Preventive monitoring programs are economically justified when compared to downstream production losses.
Toward a Hatchery Biosecurity Certification Model
This paper proposes that hatchery fungal monitoring be incorporated into structured biosecurity certification frameworks. A standardized program should include:
1. Documented cleaning and disinfection protocol
2. Defined air quality thresholds (CFU/m³)
3. Routine air and surface sampling schedule
4. Corrective action procedures
5. Annual external audit and compliance review
Such a model transforms environmental monitoring from optional practice to measurable compliance standard.
Conclusion
Airborne Aspergillus contamination in hatcheries represents a silent yet preventable risk. Evidence from both human healthcare and poultry production supports the necessity of structured environmental control. Hatchery fungal surveillance should be recognized as a core biosecurity requirement rather than a supplementary hygiene measure. Embedding environmental monitoring within certification frameworks strengthens poultry health, protects production efficiency, and aligns with One Health principles in the era of antifungal resistance.
References
Arné, P., Thierry, S., Wang, D., et al. (2018). Aspergillus fumigatus in poultry. Veterinary Microbiology, 213, 104–112.
Baddley, J. W., Thompson, G. R., Chen, S. C., et al. (2021). Invasive aspergillosis in immunocompromised patients. Clinical Infectious Diseases, 72(S2), S94–S102.
Centers for Disease Control and Prevention (CDC). (2023). Aspergillosis: Epidemiology and risk factors.
Fraaije, B. A., Atkins, S., Hanley, S., et al. (2020). The multi-fungicide resistance status of Aspergillus fumigatus populations. Applied and Environmental Microbiology, 86(15), e00711-20.
van den Berg, F., et al. (2019). Environmental surveillance of airborne fungi in poultry hatcheries. Poultry Science, 98(9), 3862–3871.
World Health Organization (WHO). (2022). WHO fungal priority pathogens list.
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Dr. Nahlan Juwair Hassan/ Poultry and Ruminant Diseases Specialist
6-4-2026
Abstract
Ectoparasites, particularly ticks and mange mites, are among the most significant health challenges in sheep farming in semi-arid environments. This case study aims to analyze the relationship between the seasonal dynamics of these parasites and the effectiveness of chemical control programs in Iraq. The literature shows that successful control depends not only on the type of pesticide but also on the timing and frequency of intervention according to the parasite’s life cycle. The results confirm that strategic application of pesticides during periods of early activity in spring and autumn, with re-treatment every 10–14 days, achieves the best levels of control. The study also highlights the importance of integrating chemical control with environmental management to achieve sustainable reductions in parasite load.
External parasites in sheep constitute a widespread economic and health problem in Iraq, leading to reduced productivity, deteriorating wool quality, and increased susceptibility to secondary diseases. Ticks are an important vector for bloodborne diseases such as Anaplasma ovis, while mange causes direct losses due to chronic skin damage.
These parasites exhibit a clear seasonal dynamic, linked to temperature and humidity, making early treatment more effective than treatment during the peak of infestation.
Studies show that:
Therefore, understanding this seasonal pattern is essential for designing effective control programs.
3.1 Amitraz
Amitraz is one of the most widely used compounds for controlling ticks and mange. It acts on the parasites’ nervous system via octopamine receptors, leading to paralysis and death. Field studies indicate its high effectiveness in reducing parasitic load when used in periodic programs.
3.2 Ivermectin
Ivermectin acts systemically and is widely used for mange, especially during periods when dipping is not feasible. However, its effectiveness against reinfection is limited, necessitating repeated doses as needed. 3.3 Pyrethroids
They are used mainly against ticks and are characterized by a rapid effect, but require careful management to avoid the development of resistance.
4.1 Spring (March-April)
Represents the beginning of parasitic activity and is the most important period for preventive intervention:
4.2 Early Summer (May-June)
Peak tick activity:
4.3 Summer (July-August)
Relative decrease in tick activity:
4.4 Autumn (September-October)
Second critical phase:
4.5 Winter (November-February)
Period of reduced environmental activity:
The literature indicates that effective tick and mange control is not achieved through individual treatment interventions, but rather through strategic, time-bound programs linked to the parasites’ life cycle.
Failure to repeat treatment within 10–14 days leads to control failure due to the persistence of eggs or treatment-insensitive larvae. Studies confirm that combining chemical control with environmental management (barn cleaning and humidity reduction) significantly increases control efficiency.
Tick and mange control in sheep in Iraq requires:
Relying on reactive, non-time-bound programs often leads to control failure and rapid re-infestation.
References
Diarrhea in Newborn Lambs: Causes, Field Epidemiology in Iraq, and Scientific Critique of Antibiotic Use
Dr. Nahlan Juwair Hassan / Poultry and Animal Diseases Specialist / Samarra – Iraq
29-3-2026
Abstract
Diarrhea in newborn lambs is one of the most important diseases with a significant economic impact on sheep farming, as it is associated with high mortality rates and reduced productivity (Radostits et al., 2007). The disease is complex, multifaceted, and multifactorial, primarily involving infectious agents such as Escherichia coli bacteria, enteroviruses such as Rotavirus and Coronavirus, and some parasites such as Cryptosporidium spp. (Merck Veterinary Manual, 2023; Constable et al., 2017). In addition to non-infectious factors, primarily poor colostrum feeding management and adverse environmental conditions (grounding, temperature, mixing, etc.), cases in Iraq generally appear as field outbreaks within enclosed barns, with the widespread and irrational use of antibiotics, particularly enrofloxacin. This review aims to examine the causative agents and field epidemiology, critically assess antibiotic use, and emphasize supportive and preventative treatment.
1- Introduction
Neonatal lamb diarrhea is one of the most common health problems in sheep flocks during the first few weeks of life (Smith & Sherman, 2009). The disease is characterized by its multiple causes and the interplay of infectious, environmental, and management factors, making it a classic example of a multifactorial disease (Constable et al., 2017). The disease leads to significant economic losses due to mortality, reduced growth, increased treatment costs, and lost season.
2- Pathogens and Pathogenic Mechanisms
The main infectious agents include:
These agents (pathogens) lead to the destruction of the intestinal epithelial cells (lining), causing malabsorption and impaired secretion of fluids within the intestinal lumen and resulting in severe diarrhea (Radostits et al., 2007). In severe cases, the primary cause of death is indirect (dehydration and metabolic acidosis) rather than the direct effect of the pathogen (Constable et al., 2017).
Non-infectious factors also play a significant role, including:
3- Clinical and Epidemiological Characteristics:
The infection manifests as watery or yellowish diarrhea, severe dehydration, general weakness, and a decrease in grazing behavior and feeding. Epidemiologically, cases often occur as outbreaks among newborns within the herd, indicating a stressful environmental factor and poor management (Merck Veterinary Manual, 2023).
4- Field Epidemiology in Iraq
Across all regions of Iraq, neonatal diarrhea is one of the most common diseases in traditional and semi-intensive poultry farming systems, and it may be more severe during the winter calving season. Field observations indicate that the disease is more closely related to housing conditions and management (handling of calving) than to being a random disease (FAO, 2021). Key field factors include:
Field reports and local research indicate that the most common pathogens are E. coli, Cryptosporidium parvum, and enteroviruses, and infections are often mixed (Constable et al., 2017; Merck Veterinary Manual, 2023).
5.1 Common Use: In many farms in Iraq, the antibiotic enrofloxacin is widely used as a first-line treatment for diarrhea without proper laboratory diagnosis (FAO, 2021).
5.2 Lack of Scientific Justification: Diarrhea does not necessarily have to be caused by a pathogen sensitive to enrofloxacin. Evidence suggests that a significant proportion of diarrhea cases are due to pathogens that do not respond to antibiotics, such as:
5.3 Pharmacological Limitations of Enrofloxacin Use
5.4 Antibiotic resistance: Irrational use of fluoroquinolones leads to the emergence of resistant strains of E. coli and reduces the effectiveness of future treatment (WHO, 2020).
5.5 Treatment recommendations: Treatment should primarily consist of:
6- Prevention and Control
Disease control depends on the following factors:
7- Conclusion
Diarrhea in newborn lambs is a multifactorial disease that depends heavily on the success of field management. In Iraq, environmental conditions, coupled with poor colostrum management, play a pivotal role in increasing infection rates. The routine use of antibiotics, particularly enrofloxacin, which is not based on strong scientific evidence in most cases, may contribute to antibiotic resistance without improving treatment outcomes. Therefore, strategies should be redirected towards prevention and supportive treatment.
references :
• Radostits, O.M. et al. (2007). Veterinary Medicine.
• Constable, P.D. et al. (2017). Veterinary Medicine: A textbook of the diseases of cattle, sheep, goats.
• Smith, M.C. & Sherman, D.M. (2009). Goat Medicine.
• Merck Veterinary Manual (2023). Neonatal diarrhea in ruminants.
• FAO (2021). Small Ruminant Health Management Reports.
• WHO (2020). Antimicrobial resistance and veterinary use guidelines.
Dr. Nahlan Juwair Hassan
28-3-2026
Abstract
Infectious Bursal Disease (Gumboro disease) is one of the most significant challenges facing the poultry industry globally, due to the continuous emergence of mutated and highly virulent strains that negatively impact vaccine efficacy and diagnostic accuracy. This study aims to review the molecular mechanisms responsible for the virus’s evasion of immunity and molecular tests, focusing on genetic variation in the high-variability region of the VP2 protein and the role of gene remodeling, in addition to assessing the limitations of molecular diagnostic tools. The study also discusses field factors associated with vaccination failure and emphasizes the importance of integrating molecular surveillance, updating vaccination programs, and improving diagnostic methods for effective disease control.
Introduction
Gumboro virus belongs to the family Birnaviridae and is a non-enveloped virus with a two-segment double-stranded RNA genome. It targets B lymphocytes in the bursa of Fabricius, leading to pronounced immunosuppression and increased susceptibility to secondary infections. Despite widespread vaccine use, outbreaks continue to occur due to antigenic drift and the emergence of mutated and highly virulent strains, necessitating a thorough understanding of the underlying molecular mechanisms.
Molecular Determinants of Antigenic Variation
The VP2 protein is the major antigenic factor in Gumboro virus, specifically its hypervariable region (HVR), which plays a crucial role in immune recognition. Mutations in this region alter the stoichiometry, reducing the ability of antibodies to bind effectively to the virus. Unlike viruses such as influenza, antigenic variation in this virus relies primarily on antigenic drift and genetic remodeling, rather than classical antigenic translocation.
Key amino acid sites (such as 222, 242, 256, 294, and 299) have been identified as being associated with antigenic changes and virulence, and these mutations contribute to the virus’s ability to evade immunity induced by conventional vaccines.
Vaccine Evasion Mechanisms
Immunization failure against disease is a multifactorial phenomenon. At the molecular level, antigenic drift in the VP2 protein leads to mismatches between vaccine strains and circulating field strains. Mutant strains, particularly those described in some regions, exhibit reduced cross-protection with conventional vaccines.
Field conditions also play a significant role in exacerbating this problem, including:
Escaping PCR and Diagnostic Challenges
Polymerase Chain Reaction (PCR) is widely used for viral detection due to its high sensitivity. However, mutations at primer binding sites can lead to reduced amplification efficiency and false-negative results.
To overcome this problem, several strategies can be adopted, including:
Genetic analysis is also an important tool for understanding the evolution and spread of strains.
Pathogenicity and Immunosuppression
Infection with the virus leads to the rapid destruction of immature B lymphocytes in the bursa of Fabricius, causing prolonged immunosuppression. This negatively impacts the response to other vaccines and increases susceptibility to secondary infections such as:
Subclinical infections resulting from mutated strains are of particular importance, as they may go undetected despite their significant impact on immune system function.
Control Strategies and Field Applications
Effective disease control requires an integrated approach that includes:
The integration of laboratory diagnosis and field management is the cornerstone of reducing the impact of the disease.
Conclusion
Gumboro virus continues to evolve through genetic mutations and remodeling, enabling it to evade acquired immunity and molecular diagnostic tools. Effective disease control requires a comprehensive understanding of these mechanisms, along with the development of modern and integrated vaccination and diagnostic strategies to ensure sustainable production in the poultry sector.
References
Dr. Nahlan Juwair Hassan / Poultry Diseases
24-3-2026
Abstract
Infectious bronchitis virus (IBV) is one of the most important viruses affecting poultry due to the significant economic losses it causes in the poultry production sector. The continuous emergence of mutant strains resulting from genetic mutations and recombination has led to the failure of many traditional vaccination programs and the continued occurrence of infections in farms. Some mutant strains, such as QX, 793B, and IS/1494, are characterized by their ability to induce different pathogenic changes and weak cross-protection with classical vaccines. This study aims to review the most important aspects related to the evolution, spread, pathogenesis, and diagnostic methods of these strains, with a focus on modern control strategies, particularly the concept of multiple protection (protectotype) and the importance of continuous molecular surveillance.
Introduction
Infectious bronchitis (IBV) is a highly contagious acute viral disease in chickens caused by a virus belonging to the avian coronavirus family. The disease primarily affects the respiratory system and can extend to the kidneys and reproductive system, leading to reduced productivity and significant economic losses.
The virus’s high capacity to generate new strains stems from its nature as an RNA virus, making it susceptible to frequent mutations and genetic recombination, particularly in the gene responsible for the S1 spike protein, a key determinant of the immune response.
Evolution and Emergence of Mutant Strains
The diversity of IBV results mainly from:
Recent studies have shown that these changes lead to the emergence of new strains with differing antigenic characteristics, reducing the effectiveness of vaccines and contributing to immune escape. Epidemiology
Various IBV strains exhibit varying geographic distribution, although some strains have become widespread globally. Among the most important are:
Field studies indicate that some of these strains may represent the majority of viral isolates in their areas of prevalence, necessitating the adoption of continuous surveillance programs to identify dominant strains.
Pathogenicity and Clinical Effects
Mutant strains are characterized by:
Some studies have reported high mortality rates in young chicks, in addition to permanent damage to the reproductive system, such as oviduct atrophy, leading to the development of unproductive hens (false layers).
Diagnosis
Accurate diagnosis relies on:
Control and Prevention
First: Immunization
Traditional vaccines (such as Mass) show limited protection against mutated strains. Therefore, the following is recommended:
The Protectotype approach, which relies on:
Studies have shown that this approach provides a broader range of protection compared to using a single vaccine.
Second: Hygiene Measures
Third: Epidemiological Surveillance
Continuous molecular surveillance is essential for:
Challenges
Conclusion
Mutated strains of infectious bronchitis virus pose a growing challenge to the poultry industry due to their ability to constantly mutate and evade acquired immunity. The best control strategies remain based on a combination of thoughtful immunization based on the concept of multiple protection, continuous molecular monitoring, and strict application of biosecurity measures.
References
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Article by Dr. Nahlan Juwair Hassan
17/2/2026
Leuciscus vorax, known locally as Shelej, Shelek, Shelej, Shalaj, Shuljiya, and Abu Aliwi, is one of the largest predatory fish in the freshwater of the Middle East. This species is characterized by its high predation capacity on small and medium-sized fish and plays a vital role in regulating the ecological balance within the rivers, marshes, lakes, and reservoirs associated with the Tigris and Euphrates basins.
This species is attractive for scientific study due to its large size, carnivorous nature, and complex lifestyle, which connects open waterways with shallow, vegetated waters. The Shelek is also known for being a difficult fish to catch due to its rapid movement, keen observation of prey, and constant monitoring of its surroundings.
Taxonomic Status
Leuciscus vorax belongs to the Cyprinidae family and is classified within the genus Leuciscus. The typical habitat of this species is mentioned in the scientific literature as being within the Tigris River basin, but it is important to emphasize that the species is widespread throughout the entire basin without being confined to a specific location. This includes:
• The main course of the Tigris and its tributaries
• The southern marshes
• Lakes associated with the basin such as Habbaniyah, Tharthar, and Razzaza
• Reservoirs and dams such as the Qadisiyah Dam and the Dokan Dam
Historical classification:
Historical classification, has been subject to debate due to morphological similarities with the European species Aspius aspius and the Caspian subspecies (A. a. taeniatus) in the number of scales and some meristematic characteristics. However, this overlap appears to represent gradual geographical variation rather than a fundamental genus difference. The distinctive diagnostic features of the shelk include:
• Number of scales in the lateral line: 82–101
• Pharyngeal teeth: 3.5–5.3 with some slight variation between specimens
• A tapered head and a terminal mouth extending to the middle of the eye
• A short, S-shaped digestive tract, indicating a specialized carnivorous nature
• Fins: Dorsal 2–3 unbranched rays + 7–9 branched fins; Anal 2–3 + 9–13 branched fins
Despite the clarity of these features, relying solely on meristematic characteristics is insufficient for definitive classification.
Therefore, it is recommended to integrate morphometric and geometric studies with molecular analysis to confirm the taxonomic identity and its evolutionary relationships.
Morphology and Physical Characteristics:
The shelk is characterized by a long, elongated body, a head tapering forward, and a terminal, elongated mouth that reaches approximately to the middle of the eye. The fins are slightly curved, and the dorsal hump is prominent behind the head, especially in larger fish.
Color and Appearance:
• Back: Greenish to blackish
• Sides: Silvery-grey or silvery-white
• Fins: Pale yellow in live fish, may tend towards red or green depending on lighting and health
• Peritoneum: Black to brown
Size:
• Lengths up to 1.5 meters and weights up to 60 kg in the Euphrates River in Syria
• In local basins such as Baghdad, lengths range from 91–102 cm and weights from 8–9 kg
Internal Body Structure:
• Short, S-shaped digestive tract, reflecting a specialized carnivorous diet
• Long, compressed, hook-tipped pharyngeal teeth, arranged in a 3.5–5.3 pattern
• Vertebrae: 51–53, supporting a rigid body for rapid movement while hunting
Habitat and Distribution:
The shelk is found throughout the Tigris and Euphrates basins, from the main rivers to their smaller tributaries, as well as Marshes, lakes, and reservoirs. It prefers shallow, open water partially covered with vegetation, but is capable of living in relatively deep areas, especially in winter.
• Found mainly in marshes and lakes between spring and autumn.
• Dams have hindered its natural migration to upper rivers.
• Its predatory behavior can be observed in shallow waters, where it leaves a V-shaped trail while chasing small fish.
Feeding Ecology:
Leuciscus vorax is a specialized carnivorous fish. Its primary diet consists of:
1. Small and medium-sized fish – the largest and most important portion.
2. Aquatic insects – especially in summer and winter.
3. Crustaceans – such as freshwater shrimp.
4. Soft-bodied organisms, algae, and aquatic plants – occasionally.
5. Frogs – for larger fish.
The size of its prey changes as the fish grows, from small to large prey. Dietary selection is also influenced by food availability and accessibility. Reproduction and Life History
• Breeding Season: February to early March
• Water Temperature: ~10°C at the beginning of the season
• Fertility: Approximately 74,500 eggs per female, averaging 1,157 eggs per gram of body weight
• Gravel bottoms and submerged seaweed are used for spawning
• Lifespan: Up to 7+ years, with rapid growth in summer when temperatures exceed 25°C
Studies indicate that older fish exhibit a high capacity for hunting and competing for food, while younger fish feed primarily on crustaceans and insects.
Conservation and Human Use:
• The sheik is a source of human food in Iraq and is sometimes caught using a hook or line.
• There is no widespread exploitation of smaller sizes (<17.3 cm).
• Some populations have been harmed by dam construction and changes in the aquatic environment.
• It plays an important ecological role as an apex predator, regulating populations of smaller fish and maintaining the balance of the ecosystem.