local names, definition, etiology,epidemiology lifecycle, pathogenesis, clinical findings, necropsy finding, diagnosis,treatment, control and prevention

1. Faculty of Veterinary Science
Infectious Diseases II
(Fungal Diseases)
RINGWORM
6th,May ,2016
SHAFI’I. A. M. SHEIKH

2. Ring Worm
Synonyms: Tinea infection, Trichophytosis,
Dermatophytosis.
It is contagious fungal infection that can affect
any part of the body. The name comes
because of characteristic red ring that appears
due to infection. Ringworm is caused by
invasion of keratinized epithelial cells and
their fibers by dermatophytosis

3. Etiology
Causative agent are fungi that grow on hair or
skin or both. The common fungi that occur in
each species are

4. Host Dermatophytes
Cattle, T. verrucosum; T. mentagrophytes ; T.rubrum
Buffalo, T. verrucosum; T. mentagrophytes ;
Horse T. equinumM.gypseum, T. verrucosum; T. M
Pig M.nanum; T. verrucosum; T. mentagrophyte
Dog, Cat M.canisM.gypseum, T.
mentagrophytesM.distorum
Camel , T. verrucosum; T. mentagrophytes

5. These fungi are strict anaerobes and asexually
spores producing. They die out under the
crust in centre of lesions. These are ectothrix
type, characterized by mycelia invasion within
hair in stratum corneum of epidermis with
arthrospores on outside of hair shaft.
Trychophyton Spp. Produce large chains

6. Microsporum Spp. Produce spores in mosaic
pattern. High humidity being conducive to
multiplication of fungus. Resistance depends
largely on immunological status of animals.

7. Ringworms occurs in every part of the world.
Affecting human and animal population.
Individual dermatophytes may have different
geographical distribution. Zoophiles
dermatophytes may cause human infection.
Trychophyton verrucosum cause suppurative
type of ringworm lesion in man in rural areas.
Some dermatophytes have geographical
restrictions.

8. Epidemiology
T. semii infection is restricted to India whereas
T. concentricum in Africa. Dermatophytes have
seasonal distribution and related to the high
rainfall and humidity outbreaks has been
noted in pet animals during summer months
in close confinement with in adequate
nutrition. Disease occurs with less morbidity
and zero mortality. Infection spreads with
direct contact, indirect contact with fomites
and animal attendant

9. Pathogenesis
Dermatophytes never invade living tissues.
Dermatophytes attack the keratinized layer of
skin, hair and nail to cause autolysis of the
fibrous structures that break the hairs and
produce alopecia. They produce skin lesions
through excretion of toxin and allergens,
which affect the basal layers and there will be
increased proliferation of cells of malphagian
layers. These toxins and allergens also act as
on the vascular components

10. As a capillary dilatation, hyperemia, and edema
takes places that cause spongiosis of the
epithelium and thus, interfere with
keratinization resulting in parakeratosis. There
are scales encrustation. The hair is complete
until the follicles are destroyed by secondary
bacterial infection. Secondary bacterial
infection may produce micro-abscess in the
superficial epidermis together with
suppurative folliculitis

11. Clinical findings
Ringworm usually appears 10 to 14 days after
contact. Different dermatophytes affect
different parts of the body to cause the
various type of lesions.
 Ringworm of the scalp
 Ringworm of the foot
 Ringworm of the body
 Ringworm of the nails

12. The affected area of the skin become
erythematous, discrete and almost circular
with raised borders have thick grayish crusts.
The lesions grow peripherally with central
healing. The lesion look like asbestosis. The
lesion coalesce. The lesion are mostly present
at the head, around the eyes, neck, ears and
dewlap. Generalized distributions of lesion
are also seen occasionally

19. Diagnosis
The epidemiological history and diagnosis of
dermatophytes is made on the basis of
characteristic lesion. The confirmation is
scrapping, hair, nails, etc.are subjected to
direct microscopic examination. Collect
materials are soaked in few drops of 10% KOH
salution in a petridish and after 30 minutes
make slide and examine under the
microscope. The presence of fungal elements
and spores may be noted.

20. Clinical materials may be cultured on
sabaurauds dextrose agar medium.
Antibacterial agents and antidione may be
added to prevent most of the laboratory
contaminants and growth may be obtained at
22-30c. Dermatophytes grow within 5-10 days

21. The skin biopsy from the suspected lesions may
be done and stained for observing fungus.
Haematoxyline and eosin stain is widely used
for histopathological examination of animal
tissues. Many fungi take this stain. Special
fungal stains such as Gomorismethanamine
silver technique (GMS). gridleys fungus stain
(GF). And periodic acid Schiffs technique
(PAS). May also be used

22. Certain stains of M. canis and M. audouninii
produce a yellow green colour fluorescence is
due to tryptophan metabolite produced by
the fungi.
The fungal antigen can be given
subcutaneously for allergic test and reaction
can be noted after 24 to 48 hours for any hot,
painful doughy swelling.

23. Treatment
Spontaneous remission occurs in
dermatophytosis within three months by
anatomical barrier of the skin and mucus
membrane. Good general nutrition and
health. Besides, neutrophils play an
important role in the inflammatory response.
The drug used in dermatophytosis can be
broadly divided into categories of local and
systemic drugs.

24. Irritants,keratolytics, fungicide, and fungistatic
drugs are used to check the ring worm.
Medicines of ring worm can be either locally
applied in the form of ointment or lotion or
systemically given. Phenol. Salicyclic acid,
benzoic acid, iodine and miconazole are used
as 2-5% as ointment

25. Cotrimazolehaloproquine, risorcinole and
tolnaflateare generally used as 1%
preparations. Systemic antifungal agents are
arise otulyinethialbendazole, nystanine and
ketoconazole. Systemic antifungals are used in
generalized infection of severe nature.
Support of ant-inflammatory and anti-
histaminic drugs are always required for early
recovered.

26. Control
The infected animals should be identified and
treated at the earliest possible. Spread can be
prevented by rearing them at isolated place.
Contaminated utensils, grooming articles,
feeding trough etc. should be properly
cleaned. The wooden doors, windows, gaits
or chain, rope should be treated with
disinfectants animal handler should wash their
hands properly before handling the non-
infected ones

27. Various vaccines have been tried and T.
verrucosum infection in cattle has been
controlled, but any commercial vaccine is not
yet available

28. Conclusion
Although ringworm is not tracked by animal
owners, infections appear to be increasing
steadily especially among pet animals. Early
recognition and treatment are needed to slow
the spread of infection and to prevent
reinfection