Notoedres spp


This is a fairly common disease in Australia. Notoedric mange, caused by Notoedres cati, is the scabby, scaly, skin disease known as head mange. Notoedres mites are closely related to Sarcoptic mange mites of dogs and thus the two infections have some similarity. Both conditions typically begin with itchy crusts and scales an the ear margins. Notoedric mange progresses to involve the face and ultimately, if the skin disease is ignored, it will cover the cat’s entire body. The term “scabies” is somewhat colloquial and refers to a mite infection with any of the mites in Sarcoptidae family.

Contents

  • 1 Diagnosis
  • 2 Transmission
  • 3 Treatment
  • 4 References

 

Diagnosis

A scraping of the crusty skin can be examined under the microscope. Mites and/or their eggs are generally not difficult to detect if they are present; still, their absence does not rule Notoedric mange out. Sometimes a trial course of treatment is needed to fully rule out the infection. The presence of the mite is highly inflammatory, hence the intense itching.

 

Transmission

Notoedres mites are spread by touch and they can certainly infection humans, dogs, or even rabbits. They do not live off their host for more than a few days at best thus transmission is generally by direct contact with an infected individual.

 

Treatment

There are several options for the treatment of this condition:

  • Organophosphate dips – In the past a series of 6 or 7 lime sulphur baths or Amitraz (mitaban®) dips were used to control this infection. This certainly works but the cat’s general dislike of bathing had created need for a more convenient treatment. Further, lime sulphur has an extremely objectionable smell and will discolour fur. Amitraz tends to produce sedation in some patients and headaches in some humans.
  • Ivermectin – This medication, which is usually given as an injection, has become the most common treatment due to its convenience and efficacy. Treatment is typically weekly or every 2 weeks for a month and recovery is prompt. One must consider though, that the cat may become reinfected if other cats in the household are infected but not yet showing symptoms or if the cat is an outdoor cat and likely to again associate with the infected individual who transmitted the infection to him in the first place.
  • Selamectin (Revolution®) – This topical medication was designed for flea, heartworm, and intestinal parasite control. In the dog, it is approved for control of Sarcoptic mange mites but due to the rarity of Notoedres cati infection, Pfizer is unlikely to pursue the expensive process of gaining FDA approval for this condition. Still, selamectin, still a relatively new product, seems to be effective. This product appears to be most beneficial in prevention of future infections (it is meant to be used monthly on an indefinite basis for flea control) and provides a convenient means to treat other housemate cats.

 

References

1. Merck Vet Manual


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