Detailed Explanation of Techniques and Methods for Pigeon Disease Diagnosis and Treatment

The purpose of pigeon disease diagnosis is to recognize the disease as early as possible so that timely and effective prevention and treatment measures can be taken. Diagnosis is the precursor to prevention and control work; only with timely and correct diagnosis can prevention and control work be targeted and achieve outstanding results. Otherwise, actions are often taken blindly, delaying the opportune moment and bringing major economic losses to the pigeon industry. Based on the patterns of occurrence and development of pigeon diseases and the physiological characteristics of poultry, the clinical diagnosis of pigeon diseases includes 3 aspects: investigation of epidemic characteristics, observation of flock and individual symptoms, and pathological anatomy.

I. Epidemic Characteristics and Individual Symptoms

(A) Investigation of Epidemic Characteristics

1. Current situation and its development process: mainly inquire about when the disease started, the age of the affected pigeons, the symptoms of the disease, the speed of disease transmission, etc., to infer whether the disease is acute or chronic, bacterial or viral, and what disease is suspected. 2. Medical history and epidemic situation

(1) Understand what major epidemics have occurred in the past at the @#@247@#@ pigeon farm or pigeon farming household, whether similar diseases have occurred, and what the course and outcome were, so as to analyze the relationship between the current outbreak and past diseases.

(2) Investigate the epidemic situation of nearby pigeon farms. If the pigeons at these farms have airborne infectious diseases such as Newcastle disease, influenza, pigeon pox, etc., they may quickly spread to this farm.

(3) Conduct an epidemiological investigation of the areas from which breeding stock was introduced.

(4) Implementation of routine prevention and control measures. Understand the epidemic prevention system and its implementation, whether strict disinfection measures are in place; what vaccines have been used for preventive inoculation of sick pigeons, whether drug prophylaxis and regular deworming have been carried out, etc., and comprehensively analyze the causes based on these.

(5) Feeding and management conditions. Mainly understand density, lighting, temperature, humidity, ventilation, feed, etc., and identify the cause of disease based on these conditions.

(6) Changes in productivity can serve as a reference for the presence or absence of disease. (B) Observation of Flock and Individual Symptoms

1. Observation of flock symptoms

Mainly observe various abnormal phenomena in the pigeon flock to provide clues for further diagnosis.

(1) Observe mental state: healthy pigeons are lively, excited, highly sensitive, with tight, glossy feathers; sick pigeons are listless, reluctant to move, slow to respond, often stay alone in a corner, with loose, lusterless feathers, etc.

(2) Observe feeding and drinking conditions: based on the daily feed records, the increase or decrease in food intake can be accurately determined. Generally, when pigeons are sick, feed intake decreases, but water intake increases.

(3) Respiratory condition: the normal respiratory rate of pigeons is 30 to 40 times per minute. Generally, common diseases and mild diseases mostly do not cause changes in respiration. Only during severe high-fever stages or when the cardiovascular system is affected and cardiac function declines does the respiratory rate increase and difficulty in breathing appear; when diseases of the respiratory system occur, almost the entire course of the disease is accompanied by varying degrees of respiratory changes. The latter is called primary dyspnea, and the former is called secondary dyspnea.

(4) Observe feces: abnormal feces is often a sign of disease. Normal pigeon droppings are gray, yellowish-brown, or grayish-black, shaped in strips or spirals, with a white substance attached at the end. The droppings of sick pigeons are mostly soft, loose, watery, green, yellowish-white, red, with a foul odor, etc.

(5) Observe movement and behavior: mainly observe whether the pigeons have abnormal phenomena such as head twisting, neck bending, accompanied by unstable standing, and backward circling, etc.

2. Observation of individual state

Among the sick pigeon flock, several sick pigeons can be selected for detailed individual examination. The main contents examined are as follows:

(1) Beak: the beak of healthy pigeons is clean; sick pigeons often have a soiled beak due to increased nasal secretions.

(2) Eyes: pay attention to observing the color of the conjunctiva, hemorrhagic spots and edema, the integrity and transparency of the cornea, etc. Inflammation of the conjunctiva, inflammation such as edema of the cornea and iris, and constriction or dilation of the pupil.

(3) Cere: the cere of healthy pigeons is bright, white, and clean. The normal cere of squabs is flesh-colored, and the cere of young pigeons gradually changes from flesh-colored to white. If the cere is soiled and moist, with a dull color, these are all signs of disease.

(4) Oral cavity: pry open the oral cavity and observe the integrity, color, and mucosal state of the tongue and hard palate. Excessive oral mucus is seen in many respiratory diseases and acute septicemia. If diphtheria-like lesions are found in the oral cavity, especially at the rear of the oropharynx, it is a symptom of pigeon pox. Keratinization of oral epithelial cells is seen in vitamin A deficiency. (5) Crop: if the crop feels dough-like when pressed with fingers, it may be hard crop disease; if the pigeon's head is held upside down while pressing the crop, and sour-smelling liquid flows out from the oral cavity, it may have soft crop disease.

(6) Cloaca: first observe whether the feathers around the anus are contaminated with feces, then use the thumb and index finger to open the cloaca and observe the mucosal color, integrity, and state, and check for congestion, hemorrhage, and necrotic lesions.

(7) Body examination: includes chest examination, abdominal examination, leg and joint examination, etc. Healthy pigeons have a sturdy body and full breast muscles, feeling firm and elastic when held in the hand; sick pigeons are generally emaciated and struggle weakly when held in the hand. At the same time, attention should be paid to checking for sternal deformity, enlarged abdominal circumference, lameness, drooping wings, etc.

(8) Body temperature: the normal body temperature of pigeons is 40.5 to 42.5 °C. Mild illnesses in pigeons do not cause changes in body temperature. If examination reveals a significant rise in body temperature, it is mostly related to acute inflammation and infectious diseases; if body temperature drops, it is often a sign of critical condition and poor prognosis.

II. Pathological Necropsy

Pathological necropsy is an extremely important diagnostic method for on-site diagnosis of pigeon diseases. For example, Newcastle disease, pullorum disease, infectious bursal disease, etc., present characteristic pathological changes, and a correct diagnosis can be quickly made through necropsy.

1. Methods of pathological necropsy

The order of pathological necropsy should first observe the external appearance of the carcass, paying attention to its nutritional status, feathers, and visible mucosa, then wet the feathers with water or disinfectant solution, then skin the bird, open the body cavity, remove the internal organs, and conduct careful systematic observation item by item in the order of necropsy,

including skin, muscles, nasal cavity, trachea, lungs, esophagus, stomach, intestines, ceca, tonsils, heart, ovaries, oviduct, kidneys, bursa of Fabricius, brain, peripheral nerves, thoracic cavity, and abdominal cavity. During necropsy, records should be kept well; after examination, identify the main characteristic pathological changes and general non-characteristic pathological changes, and make analysis and comparison. 2. Precautions for necropsy

(1) During necropsy, understand the source of the dead pigeon, the disease, symptoms, treatment history, and epidemic prevention situation.

(2) Before necropsy, prepare the necessary instruments and disinfectants, wear work clothes, and put on gloves.

(3) After necropsy, promptly clean and disinfect all used clothing and instruments. After washing hands following necropsy, wipe them with alcohol; if conditions permit, take a bath and change clothes. (4) The earlier the necropsy, the better; if too long after death, it is unfavorable for observing lesions.

(5) Before examination, prepare containers and fixative solution so that the required pathological materials from necropsy can be placed at any time.

(6) Pathological materials to be submitted for examination should be promptly placed in plastic bags or wide-mouth bottles; the carcass after necropsy and packaging materials should be deeply buried or incinerated together.

(7) The necropsy room should be kept clean and tidy, cleaned and disinfected promptly after use, and fumigated with formaldehyde solution for disinfection when necessary. Pay attention to disinfection when entering and leaving the necropsy room, and unauthorized personnel are prohibited from entering.