Demodicosis in Dogs and Cats: Diagnosis and Treatment

Understanding the Disease
Demodicosis is a complex and not fully understood disease caused by ticks. These ticks feed on the epithelium, destroying its integrity and irritating nerve endings. This leads to inflammation, hair loss, and the formation of abscesses. Infected cats and dogs may swallow ticks while grooming themselves, resulting in secondary inflammation. The disease then progresses to the necrotic skin tissue stage, accompanied by decomposition and toxic poisoning, which can cause severe conditions and death.
Transmission and Infection Methods
Infection often occurs during breastfeeding from an adult animal to its litter. Another mode of transmission is contact with a sick animal or a carrier of Demodex through contaminated items used for pet care.
Dog Demodicosis
In dogs, the main parasite responsible for the disease is Demodex canis, which lives in the hair follicle. The presence of this parasite in the skin’s microflora is normal, and the disease is associated with immune system problems that cause the parasite to multiply uncontrollably.
Cat Demodicosis
In cats, the disease can be caused by both Demodex cati, which lives in the hair follicle, and Demodex gatoi, which resides in the stratum corneum of the skin. Demodicosis in cats mainly occurs due to chronic viral infections or endocrine system problems. Siamese, Burmese, and Balinese cat breeds are more susceptible to Demodex gatoi, and infected animals are highly contagious to other cats, regardless of breed.
Symptoms
The first signs of demodicosis usually appear three weeks after infection, primarily during winter and spring due to a lack of ultraviolet rays, vitamin deficiencies, and weakened immune systems in pets. Common symptoms include:
Hairless patches on the skin, mainly on the head, muzzle, front legs, and near the eyes
Papular or pustular rashes
Itching and red skin as a result of burst pustules spreading to healthy skin, causing the condition to affect the entire body
Skin injuries from scratching, potentially lead to complications such as streptoderma and staphylococcus
General weakness and depression
Appetite problems and weight loss
Fluctuating body temperature
Hearing and vision problems may also occur
Forms of Demodicosis
Demodicosis can manifest in the following forms:
Local: Puppies are primarily infected with ticks during feeding. The ticks are localized in small areas of the skin, causing hair loss, redness, and itching. As puppies mature, their immunity increases and the Demodex canis population returns to normal. In cats, Demodex cati infection is rare and not age-dependent. Symptoms include hair loss on the head and neck. For Demodex gatoi, the primary affected area is the back, with hair loss, scaly lesions, and itching.
Generalized: This form develops after local demodicosis if the animal does not recover. It is often more difficult to treat and can be exacerbated by other infections. Symptoms include large areas of hair loss, redness, peeling, and ulcerative formations on the skin. Adult dogs typically experience a more severe course than younger ones. In cats, this type is often associated with immune system diseases or metabolic problems and is characterized by hair loss and crusty skin.
Diagnosis and Treatment Process
Diagnosis usually involves deep skin scrapings from affected areas. The skin is compressed to raise the tick to the surface and scraped until capillary bleeding occurs. The collected material is then examined under a microscope.
The treatment process is complex and involves multiple steps:
Isolating the infected animal to prevent transmission to healthy animals
Using a soap emulsion or aqueous solution of dichlorvos to clean the animal’s fur and skin
Administering medications prescribed by a veterinarian
Disinfecting or replacing collars, bedding, leashes, and other pet care items
Thoroughly cleaning the pet’s living environment
Most treatments occur at home, but severe cases may require treatment at a veterinary clinic. Treatment continues until two negative skin scrapings are obtained at two-week intervals.
Rehabilitation Process
During recovery, it is important to monitor the animal’s hygiene and nutrition. Increase protein intake and avoid fatty meat products. Choose pet food designed for allergy sufferers and consult with a veterinarian about vitamin supplements.
Prevention Methods
Young, weakened animals and offspring of infected parents are more susceptible to demodicosis. To prevent hereditary predispositions, animals that have experienced demodicosis, especially with secondary complications, should not be used for breeding.
Since infection often occurs through direct contact with a sick animal, quarantine measures are necessary. Key preventive measures against demodicosis include supporting a healthy immune system, maintaining proper hygiene, and using special care products such as collars, sprays, and shampoos.