Canine Ringworm
Just as in
humans, ringworm is not a worm but a
fungal disease that infects skin, hair,
and claws by one of the three types of
fungus: Epidermophyton , Microsporum,
and Trichophyton.
These fungi are found worldwide, and
all domestic animals are susceptible.
Ringworm carried by rodents is picked
up by curious dogs digging into rodent
burrows. The third form is a soil
fungus.
Ringworm in dogs generally appears as a
red, crusty, rough area of skin with
broken hairs and hair loss with hardly
any itching. Ringworm can, however,
present itself in many ways which are
not typical.
Due to the susceptibility of young
animals, the disease is more common in
puppies.
How does a dog get
ringworm?
Dogs can pick up ringworm
in several ways:
- Contact with hair, fur and
skin from infected animals
- Contact with contaminated
bedding, grooming equipment,
toys or environment
- Contact with soil
containing fungal
organisms
Ringworm is spread by contact with
animals which already have ringworm,
and by touching objects that the
infected animal has touched; such as
bedding, brushes or grooming equipment,
saddles and other tack, furniture,
rugs, etc. Not every animal or human
who touches infected animals or objects
will become infected; the age,
immune status, skin condition and
grooming habits of the animals
influence if the fungus is actually
able to grow and infect.
In dogs, the classic Ringworm lesions
are patchy areas of hair loss and
scaliness, usually with very little
inflammation or redness.
Animal/Human transmission of
ringworm
Some ringworm in dogs can
be contagious to people (zoonotic
disease), especially
children. People with the
highest risk for catching ringworm from
their pet are young children who have
never been exposed, the elderly, or
people with a depressed immune
system.
Once a person has been exposed to a
strain of ringworm, most develop
immunity and rarely get the same strain
again. If a person develops ringworm,
your pets should be examined, although
many times the source of infection is
actually another person and not a
pet.
Diagnosis of pet
ringworm
Diagnosis of ringworm
requires a fungal culture from a sample
of hair plucked from the edge of a
lesion. This can take several days to a
few weeks for growth and a
diagnosis.
Although the disease is considered to
be self limiting in most healthy people
and animals, treatment of infected dogs
is usually recommended to speed
recovery and prevent passing on the
fungus. Most animals will "outgrow" the
Ringworm fungus as their body's immune
system fights it off over the course of
a few weeks.
Old animals and puppies
Due to
the susceptibility of young animals,
the disease is more common in
puppies.
Animals that are immunocompromised or
very young or old are less likely to
rid themselves of the condition without
treatment.
To some extent, infection may be
persistent and widespread in longhaired
breeds of dog.
Symptoms of Ringworm in your
pet:
- Lesions, either single or
multiple
- Scaling or crusting
- Patches of hair loss that may
be circular
- Minimal to no itching
- Nodules with ulcers or draining
tracts are rare, but may
occur.
Treatments for Canine
Ringworm
Topical treatments involve
clipping the hair, bathing with
antifungal shampoo and rinses that
decrease transmission immediately. Some
cases may require systemic antifungal
therapy that has been shown to shorten
the course of the disease.Â
The anti-fungal drug of choice in dogs
is Ketoconazole. Oral medications are
generally reserved for severe and/or
chronic infections and can be expensive
and with side effects.
Treatment must continue until the
culture results are negative, even
though the animal may look better. Hair
re-grows long before the fungus is
exterminated. In a single-dog
household, treatment can last 3 to 8
weeks and may be needed for longer
periods in a multi-pet household.
- Localized infections may be
treated with topical therapy
alone.
- Systemic antifungal in
combination with topical therapy
should be used for generalized
infections or in dogs with multiple
lesions.
- Thoroughly disinfect and vacuum
the pet's environment.
- All in-contact animals should
be evaluated for possible
infection.
Home Treatment for Ringworm in
pets
Treating your home is also
important. Fungal spores can persist in
your carpet for up to 2 years, so
re-infection is a concern. The more
animals in the house, the longer the
treatment must go on before the
environment is clear. Getting rid of
the hair in the house, kennels and pet
sleeping areas are the best way to rid
the fungus from the environment. This
is why veterinarians recommend clipping
the pet’s hair
(alert the groomer). Fungus likes to
grow in dark spaces on hair and
debris.
If your pet has ringworm, change the
bag each time you vacuum. The parts of
a bagless vacuum can be soaked in
diluted bleach water between uses. The
only reliable killer of the ringworm
spores is a 1:10 dilution of bleach in
water. Use this with care because it
will stain.
Sunlight and Ringworm
Sunlight
also kills ringworm. Items that cannot
be thrown away can be left in the sun
outside to rid them of ringworm
contamination.