Lecture 16 : Animal Diseases

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With Dr. Nireeksha Jain

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Dr. Nireeksha Jain

3. ETIOLOGY,
EPIDEMIOLOGY,
SYMPTOMS,
DIAGNOSIS,
TREATMENT OF
PRODUCTION DISEASES
OF CATTLE, HORSE,
PIG, POULTRY
16
3
LECTURE
TOPICS

4. SUB - TOPICS
1. FATTY LIVER SYNDROME
2. CAGE LAYER FATIGUE
3. PEROSIS
4. RICKETS
4
16
LECTURE

5. PRODUCTION DISEASES OF
POULTRY
1) FATTY LIVER SYNDROME
This condition affects only hens, primarily CAGED LAYERS. It is a
metabolic / nutritional disease characterised by general obesity with an
enlarged, fatty liver.
ETIOLOGY
• The principal cause is Excessive Calorie intake.
• Exposure to mycotoxin, aflatoxin, calcium deficiency, stress.
• An incorrect protein : energy balance.
• Some strains of laying hen are more susceptible.
• It is seen in conjuction with Cage- layer fatigue.

6. 6
CLINICAL SIGNS
 General obesity.
 Enlarged fatty liver that becomes soft & easily damaged.
 Death is often caused by internal haemorrhage due to
rupture of liver.
 Healthy birds in the flock could exhibit Liver Haematomas-
dark red (fresh) or green to brown (old).
 Considerable amounts of fat are detected in abdominal
cavity.

7. TREATMENT & PREVENTION
 Unless caused by aflatoxin, calcium deficiency, the main treatment for this
condition is to reduce the amount of Dietary Energy consumed.
 If aflatoxin is involved, the contaminated feed must be replaced.
 If a calcium deficiency is suspected, adding large particle calcium to the diet
is recommended.
 Addition of Choline Chloride to feed as a treatment.
 If a complete layer ration is being fed, addition of Vitamins can be of benefit.
 However, control of body- fat is the only successful remedy for this
condition & is accomplished by regulation & reduction of total energy intake.

8. Cage Layer Fatigue
(Osteoporosis)
Cage layer fatigue is a term used to describe leg weakness and
acute deaths in chickens in cages, and is caused by inadequate
calcium, phosphorus and Vitamin D levels in the blood stream.
This condition may be seen even in floor birds under certain
conditions. It is seen most often in young hens early in
production.
ETIOLOGY
Although diet poor in calcium, phosphorus and Vitamin D have
been shown to produce similar skeletal changes, the condition
restricted to birds kept in cages suggests to the lack of exercise
causing poor skeletal development.

9. Cage Layer Fatigue
(Osteoporosis)
o As the name implies, the major feature of the condition is reduced bone
structure in laying chickens kept in cages.
o Initial clinical signs consist of paralysis, later becoming depressed and
dying of dehydration.
o On post-mortem examination, bones are easily broken.
o Fractures may be found in leg and wing bones.
o Ribs may be bent at the junction of the sternum and vertebral
components. The sternum is often deformed.
o Parathyroid glands are enlarged.
CLINICAL SIGNS

10. 10
TREATMENT
Affected birds removed from the cages and fed on balanced
ration recover in a week.

11. PEROSIS / SLIPPED TENDON
A disorder of poultry that is characterized by leg deformity and is
caused by a deficiency of vitamins (as biotin or choline) or
minerals (as manganese) in the diet. — also called Hock
disease, Slipped tendon.
ETIOLOGY
• Caused by deficiency of manganese, choline, zinc, either
singly or in combination (although deficiencies of pyridoxine,
biotin, folic acid, niacin may also be involved).
This condition is seen in chickens, ducks and turkeys. In
turkeys it may be an inherited deficiency of galactosamine.

12. CLINICAL SIGNS
1. Short legs.
2. Lameness.
3. Distortion of hock.
4. Slipping of Achilles tendon (or perosis).
5. Malposition of leg distal to hock.
6. In embryos parrot beak, shortened
bones.
Post-mortem lesions
1. Shortening and thickening of long
bones.
2. Tibia and metatarsus bowed.
3. Shallow trochlea.
4. Lateral slipping of tendon.

13. DIAGNOSIS
• Lesions
• Analysis of feed.
Differentiate from twisted leg, infectious synovitis,
rickets, infectious arthritis, ruptured ligaments.

14. TREATMENT & PREVENTION
▪ For flock, proceed as for prevention, no value to affected bird.
▪ Addition of manganese, choline, vitamins to the diet.
▪ Correct mineral balance.

15. RICKETS
Rickets in poultry is caused mainly by deficiencies of
either vitamin D3, calcium, phosphorus, or calcium-
phosphorus imbalance.
ETIOLOGY
An imbalance in the calcium/phosphorus ratio in the
diet results in abnormal bone development and high
phosphorus levels in the diet even with normal calcium
levels & can result in bone disease.

16. CLINICAL SIGNS
• Lameness.
• Hock swelling.
• Soft bones and beak.
• Birds go off legs.
• Poor growth.
• Birds rest squatting.
• Reduction in bodyweight.
• At post mortem, the bones may be twisted and bent. Because
they are poorly calcified the bones bend like rubber .
• Folding fractures of the long bones and the ribs, and flattening
of the rib cage may also be seen.

17. DIAGNOSIS
• History, signs, lesions.
• Differentiate from Encephalomalacia,
Femoral Head Necrosis
TREATMENT & PREVENTION
1. Over-correct ration with three times vitamin D for 2 weeks, or
Vitamin D or 25-hydroxy vitamin D in drinking water.
2. Supplementation of vitamin D, proper calcium and
phosphorus levels and ratio.
3. If the birds are developing rickets on a home-formulated diet,
then they likely have other vitamin/mineral dietary problems
as well, and so supplementation with multi-vitamin mineral
packs may be helpful.

18. THANKS!
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