What you need to know about

demodectic and sarcoptic

mange

David Grant

B.Vet. Med. Cert.SAD. F.R.C.V.S.

Canine Demodicosis and

Canine Scabies • Both canine demodicosis and canine

scabies are parasitic diseases caused by

mites invisible to the naked eye

• They are generally diagnosed from the

clinical signs and by skin scraping, hair

plucks or tape strips and identification of

the mite microscopically

CANINE DEMODICOSIS

• The disease is caused by Demodex canis

• This is a parasitic mite which is

transferred from the carrier mother to her

pups in the first 2 or 3 days of life

• Thereafter the disease is non-contagious

• This is an important distinction from

canine scabies which is highly contagious

DEMODEX CANIS LIFE

CYCLE IMAGES

DEMODEX CANIS

CANINE DEMODICOSIS-

Demodex canis

• CLINICAL FEATURES

• The disease is more common in pedigree dogs, particularly short haired

• Can occur in long-haired dogs e.g. Old English Sheepdog, West Highland White and Afghan.

• There are three forms of the disease. These are :-

• Localised and generalised

• A few cases present with foot lesions only. This is called Demodectic pododermatitis

• The majority of cases present in the first year of life-called juvenile onset

• A minority present in older dogs more than 2 years of age and usually in old age. These are called adult onset demodicosis and is associated with suppression of the immune system. These have a guarded outlook because there may be a serious underlying disease

LOCALISED DEMODICOSIS

GENERALISED

DEMODICOSIS

‘REDDE’ MANGE

CANINE DEMODICOSIS

Diagnosis • Deep skin scrapings using blunted

number 10 scalpel blade

• Hair plucks

• Tape strips using scotch diamond ultra-

transparent

• Impression smears if deep pyoderma

CANINE DEMODICOSIS-

licensed treatment • Amitraz(Aludex) 0.5% solution weekly

• Metaflumizone + amitraz spot

on(Promeris duo) every 2 weeks. This is

off label as manufacturer recommends

monthly

• Moxidectin + imidacloprid spot

on(advocate) weekly spot on

CANINE DEMODICOSIS

Unlicensed treatment • Ivermectin. Orally at a dose of 0.3-0.6

mg/kg daily Do not use in collies and

related breeds-neurotoxic. Prudent to

start with 0.1 mg/kg and build up over a

week or two until at the upper dose rate.

Commonly first choice in many parts of

the world

Before treatment with promeris

Before treatment with amitraz

Before treatment with

ivermectin

Demodectic pododermatitis

before ivermectin treatment

CANINE SCABIES

(Sarcoptic mange) • Caused by the parasitic mite Sarcoptes

scabiei var canis

SARCOPTES SCABIEI

Canine Scabies

Clinical signs

CANINE SCABIES

• DIAGNOSIS • History, physical examination, skin scrapings, ELISA

test and/or trial therapy • Often mildly pruritic initially but gets markedly worse

without treatment • Sarcoptes can be difficult to capture even with

numerous skin scrapings therefore- • Trial therapy should be given to any dog suspected of

having scabies even if scrapings are negative

CANINE SCABIES

TREATMENT Amitraz-5 to 6 weekly baths recommended, at a dilution of 250

ppm Cannot be used in Chihuahuas, puppies less than 12 weeks of

age, pregnant or lactating bitches Selamectin(Stronghold)is licensed-spot on every month for three

applications Moxidectin(Advocate) is licensed-spot on every two weeks for

three applications With therapeutic trial veterinarian should apply and monitor

(Ivermectin is effective at 200 mcg/kg subcutaneous injection x 3 at

10 day intervals but is not licensed)

CANINE SCABIES-treatment

SUMMARY

CANINE DEMODICOSIS

• Caused by Demodex canis

• Not contagious

• Not usually pruritic(except

if severe secondary

infection)

• Can be difficult to cure and

labour intensive

• Licensed and unlicensed

products available with

cure rate c 90%+

CANINE SCABIES

• Caused by Sarcoptes

scabiei var canis

• Highly contagious

• Severe pruritus which

escalates

• Most cases easy to cure

• Effective licensed products

available - seldom need to

use unlicensed. Cure rate

approaching 100%