Sporotrichosis in Dogs
Sporotrichosis is a fungal disease that affects the skin, respiratory system, bones and sometimes the brain. Infection is caused by the virtually ubiquitous dimorphic (mold and yeast) fungus, Sporothrix schenckii, which typically infects via direct inoculation - that is, through abrasions of the skin or by inhalation. The origin of the fungus is environmental; it is naturally found in soil, plants and sphagnum moss, but it can be communicated zoonotically between different animal species, and between animals and humans.
In dogs, the disease occurs more commonly in hunting dogs because of the increased likelihood of puncture wounds associated with thorns or splinters.
Symptoms and Types
Cutaneous sporotrichosis
- Bumps, or lesions on the skin surface, swollen lymph glands
- Numerous nodules that may drain or crust, typically affecting the head or trunk
- Previous trauma or puncture wound in the affected area is a variable finding
- Poor response to previous antibacterial therapy
- Combination of cutaneous and lymph form—usually an extension of the cutaneous form, which spreads via the lymphs, resulting in the formation of new nodules and draining tracts or crusts.
- Lymphadenopathy (disease of the lymphs) is common
Disseminated sporotrichosis
- Rare, occurs when the initial infection spreads into the body to a secondary location
- Systemic signs of malaise and fever
- Osteoarticular sporotrichosis occurs when the infection spreads into the bones and joints
- Sporotrichosis meningitis occurs when the infection spreads into the nervous system and brain
- Symptoms include loss of appetite (anorexia), and weight loss (cachexia)
Pulmonary sporotrichosis
- Occurs as a result of inhalation of Sporothrix schenckii spores
- Infected animal is more at risk of developing pneumonia
Causes
- Animals exposed to soil rich in decaying organic debris appear to be predisposed
- In dogs, puncture wounds associated with foreign bodies provide an increased opportunity for infection. Cat scratches provide a similar opportunity
- Exposure to other infected animals increases the risk factor
- Immunosuppressive disease should be considered a risk factor
pica
A type of ravenous appetite that causes animals to eat or lick at strange substances
otic
Anything having to do with the ear
decay
Decomposing of matter with the help of fungus and bacteria; matter is completely oxidized.
pons
The bridge at the bottom of the brain; makes up the brainstem
yeast
A type of fungus that produces buds
ion
An atom that has a positive or negative charge
doe
A female goat, rabbit, or deer that has not been spayed
rot
A type of decay that is caused by fungus or bacteria
lysis
The breakdown of something or the destruction of something, biologically speaking
nag
A type of horse that does not belong to a particular breed
splint
A type of instrument that is used to affix parts of the body that might normally move; used to promote healing.
urinalysis
An in-depth examination of the properties of urine; used to determine the presence or absence of illness
meningitis
A medical condition in which the meninges becomes inflamed
inoculation
The introduction of an animal to an organism in order to create a slight disease to induce immunity
antibacterial
Used to refer to any drug or medical substance that has the ability to slow down or stop the growth of bacteria and other such organisms.
malaise
General discomfort of the body
lesion
A change in the way that tissue is constructed; a sore
genera
The plural form of the word ‘genus.’
nodule
A small lump or mass of tissue
enzyme
A substance that causes chemical change to another
lymphadenopathy
Any disease of the lymph nodes