Sarcoptes Scabiei in Dogs

Sarcoptes scabiei in dogs is a highly contagious disease which is known to be a problem all over the world.  While the mites which cause this disease are fairly host-specific (they prefer dogs), virtually any animal or human who is exposed to direct contact with an infected canine can become infected themselves.  This disease, if left untreated, can compromise the health of the host, with death being a possibility.

Sarcoptes Scabiei (scientific name Sarcoptes Scabiei var canis) is a highly contagious mite infestation which has the ability to be picked up by other animals and humans as well.

While each of the various species of mites can infect any host (animal or human), each species seems to have its own preference of host and sarcoptes scabiei really likes dogs.  Here are some symptoms likely to be seen on the host:

• Severe itching most often on elbows, hocks, ears, armpits, chest and belly
• The severe itching can progress to all areas of the body
• Pustules (pus-filled blister-like bumps) on the skin of affected areas
• Yellow crusting on the skin of affected areas
• Infection at the site of intense itching
• Eventual swelling of lymph nodes from untreated infection
• Hair loss at infection sites, often seen as patches of lost hair

Types 

Sarcoptes scabiei, also known as mange or scabies, has various varieties in the mite family, each of which has their own “favored” host:

• S scabiei var canis - prefers dogs as their hosts
• S scabiei var vulpes - prefers the red fox as their hosts
• S scabiei var ovis - prefers sheep for their hosts
• S scabiei var bovis - prefers cattle as their hosts
• S scabiei var suis - prefers pigs as their hosts

While these variants of the mite have the above noted host preferences, they are not above infecting other animals or humans who come into direct contact with their host of choice.  Sarcoptes scabiei is rarely known to infect cats, their mite nemesis is Notoedres cati.

Basically, these mites live their entire life on dogs.  While that may not sound that bad, the “cohabitation” between species isn’t always the best option for one of the species, and, in this case, the dog gets the “sharp end of the stick” so to speak.  This is how the infestation occurs:

• Sarcoptes scabiei in dogs is caused by the female sarcoptes scabiei var canis who burrows into the skin of the host, laying many, many eggs as she moves through the skin, creating tunnels which may be several centimeters long
• Once the female has made her deposits, she dies
• The larvae generally hatch within 3 to 8 days (they have 6 legs at this stage of life)
• As the larvae matures into nymphs (still inside the burrow), they develop 2 more legs to become 8 legged
• The nymphs continue to mature into adults (still inside the burrow) 
• The adult mites mate and the whole life cycle repeats itself usually within 2 to 3 weeks
• Mites generally prefer to live on the dog their whole life but can survive in cool moist environments without their host for up to 22 days (the length of survival without the host in normal home environments is generally 2 to 6 days)

When it comes to the diagnosing process, your input will be very important.  Your veterinary professional will need some history, such as the onset of the severe itching (was it sudden or gradual), how long the severe itching has persisted, what types of environment was the afflicted animal exposed to and was the afflicted canine around other animals or people?  The diagnostic process of sarcoptes scabiei in dogs can be challenging for your veterinary professional. He will do a physical examination during which he will get scrapings of tissue from the affected areas on the skin of your pet.  

Because evidence of the presence of this mite can be hard to get, it may take several scraping attempts to get the eggs, mites or feces required to confirm the diagnosis.  A well-placed note here: a negative scraping doesn’t necessarily mean there are no mites.  The definitive diagnosis will come down to the history and the condition’s response to treatment for mange (scabies).

Treatment options for sarcoptes scabiei in dogs have several levels and, sometimes, all of them need to be utilized for effective eradication of the scabies (mites). Your pet’s veterinarian will discuss the safest and most effective option.

• Clip and dip - this involves cutting the hair if the dog is long-haired and bathing the patient in a benzoyl peroxide shampoo to cleanse the skin - then dipping the dog into an organophosphate dip every two weeks
• Dips could include products like Paramite, Amatraz, Mitaban and lime sulphur (Lymdyp) dips
• Dips would be done every two weeks for two or three times to eradicate the mite as new eggs hatch and go through their short life cycle
• These dips are quite toxic to humans and are unpleasant to do - care must be taken to protect the human and the more sensitive areas of the dog (eyes, face, ears) - some of these may not be appropriate for the very young, very aged or debilitated canine patients
• Other treatment options include application of Selamectin topically on a once a month basis - this medication also helps to prevent heartworm as well as control fleas and some species of ticks
• There are some preparations made for the Frontline product line which are also approved for treatment of sarcoptic mange
• If there is an infective component involved, antibacterial medications could also be administered, either topically or orally
• Additionally, the canine patient’s bedding and other areas occupied by the patient will need to be cleaned and sanitized to prevent reinfection

It is important to remember that any treatment option recommended and initiated will be subject to change if the patient doesn’t respond appropriately.  It is also important to remember that a single treatment application (whether dip, bath, topical solution or oral medication) will not be sufficient to adequately rid the animal of the mite infestation.  This is true because of the high degree of contagiousness, the prolific reproduction of the mite and the short life cycle of this species of mite.  

To rid your doggy family member of this malady, it will be necessary to continue the cleaning and other treatment options for a minimum of 4 weeks to have a greater chance of success.  Of course, it goes without saying that your afflicted doggy family member should be isolated during the initial stages of treatment to avoid passing the the mite along to other canines and people in your household or kennel.  Your vet will provide more information about this step based upon the degree of infestation and the condition of the patient.