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Clinical Diagnosis of Diseases

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					Clinical Diagnosis of Ruminant Animals Diseases Part I ‫الحشخيص االكلينيكي ألمراض المجحرات‬ ‫الجزء األول‬ By Prof. Dr. Ibrahim H.A. Abd El-Rahim
Professor of Infectious Diseases, Animal Medicine Department, Faculty of Veterinary Medicine, Assiut University E-mail: vetrahim@hotmail.com

Introduction

‫انًمذيت‬

Disease may be defined as “any abnormal structural and/or functional change in the tissues of the body.  Diseases caused by non-infectious agents (nutritional deficiency, metabolic disorders and others) are non-infectious diseases (general medicine) ‫انطب انؼبو أٔ األيشاض انببطُت‬  Diseases caused by infectious agents (e.g. parasites, viruses, bacteria, fungi, prion and others) are infectious diseases (specific medicine) ّ‫انطب انخبص أٔ األيشاض انًؼذي‬  Pathogenic agent + susceptible animal + growth and multiplication of the pathogen, and production of toxins + absorption + clinical signs = infectious disease ٖ‫انى سض انًؼذ‬  Infectious disease + transmission from one individual to another by direct and/or indirect contact = contagious disease (Latin, contagium = contact). ‫انًشض انٕببئي‬  All contagious diseases are infectious diseases, but not all infectious diseases are contagious diseases. ‫كم االيشاض انٕببئيّ أيشاض يؼذيت ٔنيظ انؼكظ‬  Infectious disease + transmission between animals and man = zoonotic disease ‫انًشض انى شخشن‬

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Clinical examination of ruminant animals ِ‫فحض االكهيُيكي نحيٕاَبث انًجخش‬ ‫ل‬ ‫ال‬ Firstly: The veterinarians must take the utmost care during clinical examination of animals, by attention to precautions and by giving clear instructions, that neither the patient nor the helpers are placed at risk. Secondly: On the other hand, obligation lies on the owner of the animal to inform the veterinarian of any vices (such as kicking, sideways pressing, biting) of the animal.
Instruments and requirements of clinical examinations

‫أدٔاث ٔيغخهضيبث فحض االكهيُيكي‬ ‫ال‬ In addition to protective clothing (veterinary smock or clinical coat, washable apron, long gloves of rubber or plastic) the following instruments are required: Stethoscope Clinical thermometer, Heavy and light percussion hammers, Plexer and plexemeter, Torch, Urethral catheter, Vaginal speculum, Milk stripping cup, Restraining equipment (metal wedge gag, wooden mouth gag). Stomach tube and probing. Containers for collecting samples (tubes, bottles, or plastic bags). ٌ‫ػشيف انحيٕا‬ ‫ث‬

I. Identification of cattle

The following are the principal criteria for the description of cattle: breed, sex, age, body weight, ear mark, neck band number, colouration, muzzle print, blood group formula, brand mark (or tattooing).  Breed

ّ‫انغالن‬

Some breeds are predisposed to certain diseases. All foreign breeds are highly susceptible for tropical infectious diseases.

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 Utilization

‫االعخؼًبل‬

 Fattening animal tend to develop disorders associated with intensive feeding (digestive disorders, laminitis).  Dairy cows tend to develop metabolic disorders.  Pregnant sheep tend to develop metabolic disorders (pregnancy toxaemia)  Sex and age

‫انجُظ ٔانؼًش‬

 Young animals are more likely to become ill as a result of parasitic invasion than the immune adults.  Tuberculosis and paratuberculosis are chronic diseases of adults, and so on.

 Body weight

ٌ‫انٕص‬

- Assessing the state of development and nutrition. - It enables precise drug dosage to be calculated. - Change in body weight is of some prognostic importance.

 Colour pattern

ٌٕ‫انه‬

- In the case of black-and-white or red-and-white breeds, the photosensitization only affects the un-pigmented areas of skin.

 Ear tags and neck bands ‫سلى األرٌ أٔ سببغ انشلبت‬
- Ear tags are used to identify cattle breeds of one colour. - On free-running cattle, broad plastic neck bands with a number printed on both sides are preferable.

 Branding and tattooing ‫انٕشى‬  Muzzle impression ‫بصًت انشفّ انؼهيب‬  Blood group determination ‫ة انذو‬ ‫فصيم‬

II. Case history

ٗ‫انخبسيخ انًشظ‬

It is usually easy to obtain information on the location of the disease, such as:

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 Absence of rumination, alternate bloat, colic or diarrhoea (probable location of the disease in the digestive system);  Nasal discharge, coughing or difficulty in breathing (probable location in the respiratory system);  Repeated posturing for urination, or passage of blood-tinged urine (probable location in the urinary tract);  Lameness or paralysis (location in locomotory or nervous systems); etc. Questions of particular importance are: ‫أعئهت راث أًْيت‬

 Duration of illness: ‫يذة يشض‬ ‫ال‬  Peracute (lasting for between a few hours and two days), ‫فٕق انحبد‬  Acute (3 to 14 days), ‫حبد‬  Subacute (2 to 4 weeks) or ‫ححج انحبد‬  Chronic (over 4 weeks). ٍ‫يضي‬  Nature, development and circumstances surrounding the symptoms:  Wound + muscular spasm = tetanus;  Dog bite + excitement = rabies;  Recent calving + inability to stand = hypocalcaemic paresis.  Probable cause of the condition: ‫انغبب انًحخًم‬  Feeding, husbandry and utilization of the animal.  Contact with other animals, has been purchased recently, and from where.  Treatment that has been instituted so far. ‫انؼالج انغببك‬ Improvement or no improvement after previous treatment will provide a guide to diagnosis and prognosis. Common errors in attempted treatment are: ‫أخطبء شبئؼت ػُذ انؼالج‬

 Forceful administration may resulting in inhalation pneumonia,  Peritonitis after faulty trocarization of the rumen,  Aggravation of lameness by incorrect claw trimming,  Damage to the birth canal by forceful extraction of calf.

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III. General examination

‫انفحض انؼبو‬

Features included in a general examination are:        Posture, ‫ٔظغ انٕلٕف ٔانجنٕط‬ Behaviour, ‫انغهٕن‬ Nutritional state, ‫انخغزيت‬ Physical condition, ‫حبنت انجغى‬ Body temperature. ‫دسجت حشاسة انجغى‬ Breathing rate, ‫يؼذل انخُفظ‬ Pulse rate and ‫انُبط‬ ‫ٔظغ انٕلٕف ٔانجهٕط‬

 Posture

 Arched back and tense abdomen important signs of peritonitis, particularly that resulting from traumatic reticulitis.  Holding the fore legs wide apart postural anomaly characteristic of diseases of pericardium and lungs.  Animals with head and neck stretched out and held low perhaps with the tongue extruded (oesophagus obstruction, dyspnea).  A lying animal curled up with the head turned towards the chest is symptomatic of comatose states, particularly parturient paresis.  While an animal lying flat on its side with extended limbs and head stretched backwards may have hypomagnesaemic tetany.  Behaviour ‫انغهٕن‬

 Increased sensomotor stimulation (excitability): Restlessness, throwing straw with the horns, pressing the head against objects.  Decreased sensomotor stimulation (depression, paralysis, paresis): In parturient paresis, the cow is lying down (unable to rise).  Coma (unconsciousness) due to general intoxication.  In acute lead poisoning. - Blindness, salivation, teeth grinding, pressing forwards.  Behaviour in botulism. – Recumbency with paralysis of all muscles and tongue hanging out.  In pseudorabies, restlessness and severe itching.  After a few days of severe illness, cattle become dull, apathetic and depressed.

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 Nutritional state

‫انخغزيت‬

When a patient is in a poor state of nutrition, it is necessary to find out if this is due to primary or secondary under-nutrition.  Emaciation (secondary inanition) results from illness which affects the appetite of the animal (as in febrile systemic infections), or its inability to ingest feed (actinobacillosis of the tongue).  Wasting diseases such as gastrointestinal helminths, tuberculosis and paratuberculosis) and they are usually chronic.  Diseases with continuous diarrhoea can lead to rapid emaciation.  Physical condition ‫حبنت انجغى‬

This comprises the general external appearance of the patient from the clinical aspect.  By abnormalities in bodily condition an animal may be judged to be mildly, moderately or severely ill.  It is also possible to distinguish acutely or chronically ill cattle.  The bodily condition of an animal with severe, chronic illness is characterized by severe emaciation, stiffness and apathetic appearance.  Body temperature ‫دسجت حشاسة انجغى‬ The procedure for taking an animal’s temperature is: (a) Shake the mercury column into the bulb end of the thermometer; (b) Moisten or lubricate the tube by the application of water, soap or mucus; (c) Insert the bulb (the full length of the tube) into the rectum where it can be held in position by means of a clothes peg attached to one of the caudal folds; and (d) Leave the thermometer in the rectum for about 2-3 minutes.

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Table 1. Normal body temperature in different animal species ANIMAL SPECIES Calves Young cattle Adult cattle Sheep and goats camels Horse Dogs and cats NORMAL BODY TEMPERATURE 38.5 to 39.5°C 38.0 to 39.5 °C 38.0 to 39.0 °C 38.5 to 39.5°C 36 to 37 37.5 to 38.5 38 to 39

In general, animal temperatures will vary, depending on the following factors: Age, time of day, environmental conditions, physical activity (work), and reproductive function.

Fever

ًٗ‫انح‬

Fever is a pathological state of increased heat production (increase in the intensity of metabolism) and decreased heat loss. It is an important curative and defensive process.

Fever is usually accompanied by:
Water retention, Digestive disorders, Increased breathing rate and heart rate The skin surface temperature is mostly increased, Dryness of mucous membranes, In cattle, the muzzle is dry, The eyes shine “feverishly” and Sometimes, the animal shivers.

Degree of fever:
Table 2. Degree of fever in cattle DEGREE OF FEVER Mild fever Moderate fever High fever CATTLE 39 .5 to 40°C 40 to 41°C 41 to 42°C
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Hypothermia
Pathological lowering of the body temperature in cattle to below 37.5 °C is called hypothermia.

The course of fever:
 Biphasic fever: Viral infections are sometimes accompanied by a biphasic temperature curve, in which the first peak is due to viraemia, and the second to bacterial secondary infection.  Saw-shaped fever curve: Temperature wit striking daily variations (Peritonitis).  Persistent fever: (in severe, acute bronchopneumonia, malignant catarrhal fever, and certain forms of mastitis (E. coli infection).  Continuous  Remittent  Intermittent  Recurrent  Atypical  Breathing (respiratory) rate ‫يؼذل انخُفظ‬ Breathing rate is the number of the respiratory movements per minute, by watching movements of the costal arch and flank. Table 3. Normal respiratory rates in different animal species ANIMAL SPECIES Adult cattle Young calves Sheep and Goats NORMAL BREATHING (RESPIRATORY) RATE 15-35 20-50 12 to 20

In examining respiration in an animal, give attention to the following factors:  Rate –number of inspirations per minute.  Depth – the intensity or indication of straining.  Character – normal breathing involves an observable expansion and relaxation of the ribs (costa) and abdominal wall.

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 Rhythm – change in duration of inspiration and expiration.  Sound – normal breathing is noiseless except when the animal is exercising or at work. Snuffling, sneezing, wheezing, rattling, or groaning may indicate something abnormal.

Pathological conditions
- Polypnea means a pathological increase in breathing rate. - Oligopnea means a decrease in breathing rate. - Dyspnea – labored or difficult breathing.  Pulse rate

‫انُبط‬

Pulse rate is the number of pulse beats per minute. This is detected by palpation of a suitable peripheral artery, such as: - In cattle: External maxillary artery, directly after its passage around the mandible, laterally at the anterior edge of the masseter muscle. Coccygeal artery, I or 2 handbreadths from the base of the tail can be also easily palpated. - In sheep and goats, the saphenous artery, which runs down the inside of the hind leg, is the most accessible location. - In horses, pulse may also be taken on the inside of the forearm (radial bone) where the radial artery travels down the bone. The important factors to note in taking the pulse are: (1) Frequency: Counting the number of heartbeats occurring in 1 min. Tachycardia is an increase in pulse rate while bradycardia is a decrease. (2) Rhythm: Pulse rhythm is normally regular, which means that the intervals between individual pulse waves are of equal duration. Irregularity is accompanied by unevenness of the pulse beat. (3) Quality: Quality is best described as the tension on the arterial wall; it is an indication of the volume of blood flow.

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Table 4. Normal pulse rates in different animal species ANIMAL SPECIES Unweaned calves Young cattle Barren &newly-calved cows Heavily pregnant cows Large bulls & oxen Sheep and goats  Summary of findings NORMAL PULSE RATE 90 to 110 70 to 90 65 to 80 70 to 90 60 to 70 60 to 90

‫يهخض انفحض انؼبو‬

When the general examination has been completed, a short summary of the findings should be made, together with facts derived from the history, in the following form: 1. The general health of the animal is not, slightly, moderately, or severely disturbed. 2. The location of disease is probably in skin and sc tissue, lymphatic system, circulatory system, respiratory system, digestive system, urogenital system, locomotor apparatus, CNS.  The special examination.

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VI. Special examination

‫انفحض انخبص‬

Special examination is to examine individual body systems more thoroughly for diagnosis and differential diagnosis:          Hair, skin, SC tissue and visible mucous membranes ‫انجهذ‬ Lymphatic system ٖٔ‫انجٓبص انهيًفب‬ Circulation ٖ‫انجٓبص انذٔس‬ Respiratory system ٗ‫انجٓبص انخُفغ‬ Digestive system ًٗ‫انجٓبص انٓع‬ Urinary system ٗ‫انجٓبص انبٕن‬ Genital system and udder ٖ‫انجٓبص انخُبعب‬ Locomotor system ٗ‫انجٓبص انحشك‬ Central nervous system ٗ‫انجٓبص انؼصب‬

Hair, skin, SC tissue, and visible mucous membranes ‫فحص الشعر والجلد والنسيج جحث الجلد واالغشيه المخاطية‬ When compiling the case history, questions will have been asked about: - Previous occurrences of skin disease on the farm, - The density of cattle within the buildings, - Care of the hair coat (whether regular grooming, shearing, washing or dipping is carried out), - Type of bedding, - Possibility of injury, - Whether any dressing has been applied to the skin (disinfectant, antifungal agent, anti-parasitic agent, etc.).

Hair

‫فحص الشعر‬

 Rough or shaggy coat (prolonged nutritional deficiency or chronic parasitic infestations).  Photosensitization  Flealthy hair: As a result of sweat & sebaceous glands secretions.  Dull coat: Due to Underproduction of sebum (asteatosis).  Hairs covered with bran: Overproduction of sebum (seborrhoea) or dandrof (as if bran had been scattered over it).  Alopocia: Alopocia is loss or shedding of hair. It may be regional or general alopecia. Louse and mange mite infestation.
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Skin “the skin is the mirror of health”

‫فحص الجلد‬

 Localized (itching) pruritus (ectoparasitosis, particularly mange).  Persistent, severe, generalized pruritus (pseudorabies).  Skin thickening (sarcoptic mange, parakeratosis (zinc deficiency).  Dermatitis (inflammation of the skin)  Wounds, necrosis of small or large areas of skin, skin ulcer  The ectoparasites include: Ticks and mange mites (Sarcoptes bovis, Chorioptes and Psoroptes).

Subcutaneous tissue (subcutis)
1. 2. 3. 4. 5. 6.

‫فحص النسيج جحث الجلد‬

Dehydration (skin fold test) The disappearance of fat deposits in severe emaciation Oedema (major disturbance of venous blood flow to the heart). Hypoproteinaemia (bottle jaw). An abscess A haematoma (accumulation of blood under the skin). 7. Subcutaneous emphysema (accumulation of air or gas). 8. Parasites: 3rd -stage larvae of the ox warble fly (Hypoderma bovis)

Visible mucous membranes

‫فحص االغشيه المخاطية‬

1. Yellow staining from deposition of bile pigments (Jaundice). 2. Non-haemolytic anaemia is manifested by extreme paleness. 3. Bluish-violet (cyanosis) occurs during circulatory disorders. 4. Reddening is usually due to local or general inflammation. 5. Petechtae (in the various forms of haemorrhagic diathesis). 6. Nodules (papular stomatitis, 7. Vesicles (vesicular stomatitis, infectious pustular vulvo-vaginitis), 8. Aphthae (foot and mouth disease). 9. Erosions (as in infectious rhinotracheitis). 10.Necrosis (as in malignant catarrhal fever and BVD. 11.Deep ulcerative defects surrounded by a raised edge (ulcers).

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Examination of the lymphatic system ٖٔ‫فحض انجٓبص انهيًفب‬

Lymph nodes

‫انغذد انهيًفبٔيت‬

The body lymph nodes are normally: - Flaccid or tautly elastic, - Easily displaced and - In one piece. During inspection and palpation attention should be paid to: - Increase in size, - Tenderness, - Firm consistency, - Nodule formation, - Adhesion to surrounding tissues, and - The occurrence of accessory lymph nodes. Examination of lymph nodes:

‫فحض انغذد انهيًفبٔيت‬

o Lymph nodes of the head and neck Mandlbular lymph nodes Parotid lymph nodes Retropharyngeal (suprapharyngeal) lymph node The external retropharyngeal lymph nodes. o Prescapular (superficial cervical) lymph nodes o Prefemoral (subiliac) lymph nodes. o Mammary lymph nodes Examination of the circulatory system ٖ‫فحض انجٓبص انذٔس‬

Heart ‫انمهب‬
In cattle the heart occupies a ventral position in the thoracic cavity between the 3rd and 6th pairs of ribs. The apex of the heart points slightly backwards and to the left, so that about three-fifths of the heart muscle is on the left of the midline, and the remainder on the right. Consequently the main site for examining the heart is on the left side. Examination of the heart comprises: Observation, Palpation, Percussion, Auscultation ‫يالحظت‬ ‫ال‬ ‫انخحغظ‬ ‫انصذو أٔ انطشق‬ ّ‫انغًبع بإعخخذاو انغًبػ‬
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Observation:

‫انًالحظت‬

Tremor in the chest wall (the heart beat is so exaggerated) Congestive oedema in the dewlap (severe cardiac insufficiency).

Palpation:

‫انخحغظ‬

Action of the heart can be felt with the finger tips by laying the left hand flat against the chest inside the left elbow at the fourth (if necessary 3rd and 5th) inter-costal space. Normally the apex beat cannot be felt in fat cattle, but it can be felt in lean cattle. You have to notice the following: Displacement, Weakening, Strengthening or Arrhythmia.

Percussion: ‫انصذو أٔ انطشق‬
Using a small soft-tipped hammer and a pleximeter or by using the fingers. On the left side of healthy, adult cattle this area is the size of the palm of a hand, while on the right side it is smaller or indistinct. You have to notice the following: Pulmonary emphysema (cardiac dullness is smaller). Hydropericardium (extensive and pronounced dullness). Pericarditis (dullness cover area in front of, and behind scapula). Hydrothorax (Increase in intensity & extent of cardiac dullness). Portion of the reticulum in the thoracic cavity (complete dullness behind the heart). - Sensitivity of the patient to percussion in the heart region.

Auscultation ّ‫انغًبع بإعخخذاو انغًبػ‬
Using tubed phonendoscope (stethoscope). The chest piece should be pressed firmly against the chest on the left side in 3rd & 4th intercostal space beneath and above the tip of the elbow. Normal heart sounds: 1. First (systolic) heart sound: longer, deeper and louder than 2nd. 2. Second (diastolic) heart sound is shorter, higher and more gentle. - Heart sounds is (bub – dup), equivalent to lub - dupp in man. - Listening to cardiac function is (F-I-R-D-A= frequency, intensity, rhythm, demarcation & any adventitious sounds).

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Heart frequency

‫يؼذل َبعبث انمهب‬

Normal heart rate Heart frequency (heart rate) usually coincides with that of the pulse. Tachycardia Increase of the heart rate. A rate of over 90 in resting, adult cattle, over 100 in young cattle or over 120 a minute in calves denotes tachycardia, a symptom of circulatory disorder. Bradycardia Slowing of the heart rate in cattle to less than 65/minute (bradycardia). Intensity of the heart sound ‫شذة َبعبث انمهب‬

Intensity of the heart sound is normally strong and even; upon auscultation the sounds are clear and of a uniform strength. A more or less pronounced increase in the first heart sound occurs during increased heart work of physiological or pathological origin (bodily exertion, psychic excitement, anaemia, cardiac insufficiency). Heart rhythm Normal heart rhythm Heart rhythm is normally regular with no change in the duration of the first and second heart tones nor in systole and diastole at the same heart rate. Abnormal heart rhythm: Duplication of the second heart sound Pronounced cardiac arrhythmia Demarcation or distinctness of the heart sounds ‫حذٔد َبعبث انمهب‬ ‫إَخظبو َبعبث انمهب‬

- Demarcation or distinctness of the heart sounds refers to the clarity of onset and termination. - Indistinctly terminated (blurred, rolling) heart sounds may be the first sign of incipient valvular endocarditis. Occurring with tachycardia, such sounds are an indication of deteriorating heart function.

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Adventitious heart sounds (murmurs)

‫ػبسض َبعبث انمهب‬

- Adventitious heart sounds (murmurs) comprise any that are additional to the first and second sounds, regardless of the nature of the sound. - They are almost invariably pathological features, and are divisible into endocardial and exocardial (or pericardial) murmurs. - Adventitious sounds are also caused by malformations in the heart, such as persistent foramen ovale (organic murmur).

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