Foot and mouth disease is a highly contagious viral disease that affects cloven-hooved animals. It causes the formation of vesicles in the mouth and on the feet. The disease is caused by a picornavirus with multiple serotypes. Clinical signs include fever, vesicles in the mouth and on the feet that can rupture and cause lameness. The disease is typically self-limiting but can have severe economic impacts. Diagnosis involves virus detection by tests like PCR. Control relies on vaccination and movement restrictions.

1. FOOT & MOUTH
DISEASE
ABHIJITH SP
CVAS, POOKODE

2. FOOT & MOUTH DISEASE
• Highly contagious febrile infectious viral disease of many
wild and domestic cloven footed mammals.
• Formation of vesicles in the epithelial tissue especially in
squamous epithelium (Stratum spinosum is involved).
• Vesicles are formed in lips,muzzle,tongue,udder, fore-
stomach, interdigital space, coronary band of feet, teats
etc.
• Low mortality, but high morbidity

3. Etiology
• Agent-Picornaviridae family-Aphthous virus genus—
FMDV
• Seven immunologically different serotypes- O,A,C, Asia –I,
SAT- I, SAT-II & SAT-III ( Different antigenic subtypes
under each serotype, no cross protection hence vaccination
failure is common)
• O,A,C, Asia –I – Asian countries SAT- I, SAT-II & SAT-III
• O,A,C, SAT- I, SAT-II & SAT-III – African countries
• Synonyms-Aphthous fever, Panters
• In India after 1995, strain C was absent.

4. Susceptible Host
• Cloven footed animals- ruminants, pigs etc.
• Cattle is most affected
• Cattle- Indicator host
• Pigs – Replicator host, Amplifier Host
• Goats & Sheep- Maintenance host

5. Route of infection
1. Ingestion of feed and water contaminated by
infected material like saliva, urine, feces, milk and
discharges from lesions of infected animal.
2. Inhalation as virus will be present in the exhaled air
( Esp. in pigs) and carried as aerosols ( Via dust)
3. Contact with contaminated bedding materials and
other fomites
4. Rapid spread due to small size of virus

6. INCUBATION PERIOD
• OIE recognizes IP as 2-14 days.
• The viral dose, susceptible species, and route of
infection all influence the speed with which signs of
illness appear.
• Also IP varies according to the serotypes.
• OIE List A Disease

7. Pathogenesis
 Through inhalation or ingestion, virus get into the body of animal.
 Initial replication in the pharyngeal lymphoid tissue or tonsils and they replicate in the
lymph node.
 They move to lymphatics and through veins they get into systemic circulation.
 Now its viremia stage (Virus in blood).
 Since it is epitheliotropic, localization in the regions of epithelial tissues of mouth,
skin and feet and in organs like mammary gland, lymph nodes, thyroid glands,
adrenals etc.
 Second phase of replication in areas of localization and forms lesions.
 Recovered animals may become panters because thyroid is affected and BMR is
altered.

8. Clinical signs
• Onset of disease is by sharp rise of temperature (104 to 106).
• Anorexia, Sudden drop in milk yield.
• Formation of vesicles- inner lips, cheeks, gums, hard palate,
dental pad, sides and dorsum of tongue, muzzle, external nares,
interdigital cleft, coronary band, teats etc.
• Usually, Blisters produce secondary bacterial infection.
• Smacking of lips, Grinding of teeth, Drooling of saliva,
Kicking of feet etc. (due to blisters)
• Loss of heat control (panters)

9. Clinical signs
• Vesicles in mouth causes excess salivation – Stringy/ ropy salivation.
• Lameness due to foot lesions, hooves may slough off.
• Mastitis will occur if teats are affected.
• Pregnant animals may abort.
• Islets of pancreas can get affected leading to diabetes mellitus.
• High Mortality occurs in pigs.
• Blister are common in snout region for pigs.
• Since vesicles occur at pressure points in pigs-Knuckling.
• In cattle, Milk may have virus up to 3 months

10. Gross lesions
• In the oral cavity, there is buccal hyperemia with development of vesicles
on inner lips, cheeks, gums, hard palate, dental pad, sides and dorsum of
tongue and muzzle.
• Foot lesions are also in the form of vesicles in the interdigital cleft and
coronary band.
• In udder, vesicles may form on teats and they may burst.
• Sometimes the epithelium sloughs off forming ulcers with raw red bases.
• Mottled myocardial lesions.
• Thyroid atrophy.
• Myocardial hemorrhage.
• Fluid presence in myocardium.

13. Gross lesions
• In young animals/ calves, FMD is characterized by grayish
white streaks on the ventricular and papillary musculature and
septal wall especially of left ventricle – TIGROID HEART due
to special pattern in ventricular musculature.
• Cause of Death in Suckling calves-Acute Myocarditis.

14. Microscopic lesions
• Cells of stratum spinosum are affected, virus replicate in the
cytoplasm.
• Ballooning/ Hydropic degeneration, spongiosis, acantholysis,
finally forming vesicles.
• Roof of the vesicle- Stratum granulosum, lucidum and
corneum, Base- Stratum germinativum
• Vesicles coalesce and form bullae.
• Sometimes the epithelium sloughs off forming ulcers.
• Lesions in mouth can be described as vesicular & ulcerative
stomatitis.

15. Microscopic lesions
• In young calves- Hyaline degeneration and necrosis of myocardial
fibers with large numbers of infiltrating lymphocytes and a very few
neutrophils – Mononuclear/lymphocytic and necrotizing myocarditis
• No inclusion body formation.
Microscopic image of calf ’s heart (“tiger-heart”)
from a calf that died from an acute form of
FMD, showing severely affected muscle fibers
with coagulative necrosis), with infiltration of
lymphocytes. (PAS stain, 600x)

16. Diagnosis
• Tentative Diagnosis: History, Clinical Signs, Details from owner.
Laboratory Diagnosis:
1. Swab Test-Swabs from mucosal eruptions and Pharynx are
taken and cultured to check the presence of virus.
2. Complement Fixation Test
3. Virus Neutralization Test
4. PCR,RT-PCR, ELISA, Electron Microscopy.

17. Differential Diagnosis
• 1.Vesicular Stomatitis
• 2.Rinderpest
• 3.Blutongue
• 4.Malignant Catarrhal Fever

18. Prevention and Control
• Proper Hygiene measure should be practiced.
• Vaccination should be properly practiced.
• Ring Vaccination is practiced
• Vaccine: Raksha “O”VAC
• Vaccination started at 4 months of age.

19. Special Points
• 1.Most Common strain-O
• 2.Immunogenic viral polypeptide-VP1
• 3.Cause of death in neonates-Acute myocarditis.
• 4.Size of virus-very small (Pico)
• 5. Semen and Urine can also carry virus, so during mating
it can be spread.
• 6.It is a zoonotic disease with very little problems in
human.

20. Thank You