Demodicosis is a skin disease caused in dogs by the characteristically shaped Demodex canis mite (Fig. 1). In cats, the disease is caused by Demodex cati mites, is extremely rare and is usually associated with an immunodeficiency state due to non-infectious or infectious diseases. Signs of infection become visible only when the number of ticks increases significantly, often against the background of other diseases. Other species are also found in cats and dogs, for example, Demodex gatoi, which can cause itching in cats and may not be diagnosed for a long time even with a careful approach to research. The entire life cycle of mites takes place on one host; they live in hair follicles (Fig. 2) and sebaceous glands.
Symptoms
Clinical symptoms appear as the number of ticks increases. Ticks feed by piercing the epithelium and absorbing the contents of skin cells.
There are two types of disease:
- Localized demodicosis (Figures 4a and 4b) is characterized by the appearance of one or more areas of nonpruritic alopecia with erythema. Slight peeling may occur. Lesions are most often located on the face, especially around the eyes or at the corners of the mouth. It does not look aesthetically pleasing, but it usually occurs in a fairly mild form and often resolves on its own.
- Generalized demodicosis, also known as glandular mange, consists of several erythematous lesions and patches of alopecia that may coalesce over time. Ears and paws may be affected. More severe cases are often accompanied by secondary bacterial infection, itching and inflammation. Demodicosis of the footpads is often accompanied by a secondary infection and can be particularly painful. In some cases, the disease becomes chronic and the lesions may crust over and bleed.
Also, juvenile generalized demodicosis is distinguished separately.
Rice. 4a
Rice. 4b
Treatment
As soon as you notice the first signs of the disease, you should turn to folk remedies and lubricate the lesions with fish oil, then increase your intake of vitamin A and start changing the litter more often.
Try to see a veterinarian as soon as possible, because further therapy and medications used depend on the specific type, causes and stage of progression.
In the early stages, you can do without antibiotics and pills. Treatment takes place at home and takes from 4 weeks to 3 months, depending on the stage and severity of the disease. If the infection is secondary, then the disease that provoked it is first treated, only after that it will be possible to limit the proliferation of parasites.
In the focal form, bathe the dog several times at specified intervals with antibacterial medicated shampoo and lubricate the bald spots with lotion. Scrapings will be taken every 2 weeks to show what is happening to the mites.
The generalized form is treated with external agents, which are added to the water when bathing or dripped directly onto the skin. The dog will also have to be neutered to avoid inheriting the disease.
In other cases, drugs and therapy are selected individually, effective sulfur ointments and special solutions are used. For secondary bacterial infection, antibiotics are used. Since most medications are “heavy” medications that have a detrimental effect on the liver, liver-supportive therapy is carried out using special tablets. Immunostimulants are mandatory.
Risk of infection for your pet
Breed and age predisposition
Demodex spp. are highly host specific and are ubiquitous in the dog or cat population, although the disease is very rare in cats (1).
Ticks are commensals of the skin; they are believed to be transmitted from the female to her offspring during feeding. Transmission of the infestation appears to be limited between adult dogs, and the lack of disease manifestation in most infected animals makes the disease harmless to surrounding animals. The environment is also not a source of infection.
Generalized demodicosis usually develops in purebred animals and is especially common among some breeds.
One review (3) identified these breeds as:
- Shar Pei
- West Highland White Terrier
- scotch terrier
- English bulldog
- boston terrier
- German dog
- weimaraner
- Airedale
- Alaskan Malamute
- Afghan hound
The disease is usually first noticed between 3 and 18 months of age. In most dogs it resolves over time. The remainder of the dogs may subsequently develop clinical signs, usually at 4 years of age or more.
It is believed that demodicosis, which began at a young age, is hereditary in nature, therefore it is not recommended to use sick animals for breeding. Generalized demodicosis, which begins in an adult animal, often develops secondary to immunodeficiency conditions, such as an inconspicuous neoplasm.
There is no risk of infection for humans.
Where does demodicosis come from?
Much veterinary research has been conducted on this topic. Demodex Canis is found in the natural cutaneous fauna of animals.
With some external or immune changes, parasitic individuals wake up from sleep and begin to reproduce.
Demodicosis has favorable factors:
- - Mostly young dogs under one year old and older dogs over ten years of age are affected by the disease. Causality is a weak immune system in both cases.
- - genetic factor on the maternal side.
- - seasonal manifestations - from mid-spring until the beginning of autumn.
- - stressful state.
- - unbalanced menu.
- — weakening of the immune system is the root cause of demodicosis.
- - failure to follow all recommendations for caring for a pet - lack of hygiene, infrequent anthelmintic treatment, contact with stray dogs.
- - contact with a sick individual.
Infection with Demodex Canis occurs through close contact or touching zoozones. The lesions form there - the muzzle, lips, ears, eyebrows, eyelids, chest and forelimbs.
The main feature of demodicosis is that an individual with a strong immune system will never become infected.
The initial symptoms of the disease are visible externally even in severe situations.
Scaly (focal) demodicosis is a mild form. Incessant itching, hair loss in infected areas, possible number of three to five lesions.
The duration of the period is seven to fourteen days.
Pustular demodicosis is a worsening of the scaly form or an independent stage. Purulent formations form.
A month after the onset of the disease, the purulent foci burst and the pus goes outside. The resulting wounds stink.
If therapy is not prescribed at this stage, a transition to a generalized form follows.
The most severe period in the evolution of the disease. The lesions are extensive.
Without prescribing therapy, two to three months and the dog is completely bald. Demodex Canis migrate to internal organs. The dog refuses to eat and drink, resulting in exhaustion and death.
Generalized juvenile demodicosis - the genetic inheritance goes from a bitch to puppies up to a year old. The treatment is long and difficult. On forums and in reviews you can often come across questions about further breeding. Here the answer is clear - no, the recovered individual is subjected to sterilization.
What can it be confused with?
A similar clinical picture may occur:
- Allergic diseases
- Bacterial dermatitis
- Dermatomycosis
- Endocrinopathies
- Parasitic diseases, such as sarcoptic mange
Diagnosis of demodicosis
Diagnosis is based on clinical signs - alopecia, sometimes accompanied by itching and flaking. Secondary infection is possible. Diagnosis can be confirmed by identifying mites or (rarely) eggs in deep skin scrapings (dry or using liquid paraffin), in shed hair samples, or in biopsies. The material is placed on a glass slide and examined under a microscope with a magnification of X100-400. Additionally, you can add petroleum jelly to the material and then cover it with a coverslip. Magnifications from X100 to X400 reveal adult ticks measuring approximately 0.2 mm in length, with a characteristic elongated body and four pairs of short legs at the front (Figure 1). If the scrapings are dry, then instead of liquid paraffin, 10% potassium hydroxide can be used to clean the drug from contaminants. In a comparative study of scraping, hair loss and biopsy methods, deep scraping was found to be the most sensitive method (Fig. 3) (Bensignor, 2003).
Rice. 1
Rice. 2
Rice. 3
Treatment of demodicosis in Rostov-on-Don
The prescribed method of treatment directly depends on the breed and age of the dog. If there are less than five bald spots, then the veterinarian will only prescribe you medications to boost the body’s defenses, but if the disease has already begun to progress, you will have to use various medications. The most popular drug is Ivermectin, but it is not suitable for all breeds and may have side effects. Therefore, treatment should always be coordinated with a doctor at our clinic in Rostov-on-Don and carried out under his supervision.
Treatment and prevention of demodicosis
In some cases, localized infestations that begin at a young age go away on their own over time.
If therapy is necessary, it is recommended to use acaricides specifically designed to eliminate Demodex spp.
Possible treatments were reviewed by Müller in an evidence-based review published in 2004 (4) and by a panel in 2011 (5).
In a study (link), isoxazolines (afoxolaner, etc.) showed a positive result in the treatment of demodicosis. Treatment should be continued until clinical signs disappear and negative results are obtained in scrapings or shed samples taken twice after the clinical signs disappear, at monthly intervals.
For generalized invasion, anti-inflammatory drugs (to relieve itching) and antibiotics (to treat secondary bacterial infections) may be required.
In the case of generalized demodicosis, long-term therapy may be required, especially if the underlying disease that caused the demodicosis has not been identified or treated.
In a number of such cases, despite constant treatment, only limited improvement or no results are achieved. Sometimes a significant improvement in the animal's condition and even complete disappearance of clinical signs can be achieved, but after some time the disease recurs or clinical remission can be achieved by repeating treatment at certain time intervals.
Treatment is usually considered successful if remission continues for 12 months without therapy.
Demodectic mange in dogs. Treatment. Prevention
Skin lesions in dogs account for about 70% of the structure of dog pathologies. A high percentage of them are parasitic diseases of the skin and its derivatives, and in particular demodicosis (demodectic scabies, red scabies).
Demodicosis is a common skin disease of dogs caused by Demodex canis mites. Mites spend their life cycle on the host and can be found in hair follicles and sebaceous glands. The disease occurs in two forms: localized (scaly) and generalized (pustular) and is a clear example of immunosuppression associated with parasitic infestations. Despite the fact that immunosuppression is not the cause of demodicosis, it has been established that generalized demodicosis in dogs leads to its appearance.
It is assumed that an immunosuppressive factor induced by the tick population is present in the blood serum of sick dogs.
Canine demodicosis is diagnosed based on general symptoms, as well as when demodectic mites are detected in scrapings from the animal’s skin.
In the scaly form of this disease, deep scrapings are made both at the site of the affected skin area and the healthy one to detect mites. In the pustular form, the contents of the pustules are examined.
As a differential diagnosis, diseases such as sarcoptic mange, ringworm, and, in puppies, juvenile cellulitis should be excluded.
Treatment for this disease has been developed for a long time and there are a large number of products on the market for timely assistance to a sick animal. The most common of them are “Ivermek-gel”, “Otodectin”, “Acaromectin-spray”. Such drugs are prescribed only by a veterinarian, as they require taking into account the dosage of the drug, you need to know the breed of the dog and its weight.
There are also means to prevent this disease, such as Advocate drops on the withers. They indicate the weight of the animal for which they will be suitable.
In the event of an animal illness, toileting of wounds and lesions is essential. “Pharmoxidine 1%”, “Chlorhexidine 1%”, “Migstim-spray” are suitable here. To stimulate the growth of the hair follicle, it is also necessary to add “Medical Sulfur” to the animal’s diet, also based on the dog’s weight. Treatment should be carried out not only in the area of skin lesions, but also within a radius of 5 cm near it.
At the time of treatment, the animal must be isolated from other animals.
Treatment is always selected individually and only by a veterinarian.
Literature
- Beale, K., 2012. Feline demodicosis: a consideration in the itchy or overgrooming cat. Journal of Feline Medicine and Surgery 14 209-213
- Bensignor, E. 2003. Comparison of three diagnostic techniques for Demodex canis demodicosis in the dog. Prat Med Chir Anim Comp 38 167-171
- Miller, WH, Wellington, JR, Scott, DW, 1992. Dermatologic disorders of the Chinese Shar Peis: 58 cases (1981-1989). J Am Vet Med Assoc 200 986-990
- Mueller, R. S. 2004. Treatment protocols for demodicosis: an evidence-based review. Veterinary Dermatology 15 75-89
- Mueller, R.S., Bensignor, E., Ferrer, L., Holm, B., Lemarie, S., Paradis, M., Shipstone, M.A.,
2012. Treatment of demodicosis in dogs: 2011 clinical practice guidelines. Veterinary Dermatology 23 86-96
