Nguyen Van Dang, Nguyen Khanh Thuan, Nguyen Phuc Khanh, Nguyen Thanh Lam*

Tran Duy Thanh, Pham Trang Thanh Nguyen

1. Introduction

Canine demodicosis is one of the most common cutaneous infections encountered in canine practice. The disease is defined as an inflammatory skin infection of parasitological origin. The disease is caused by Demodex mites, mainly Demodex canis and to a lesser extent Demodex injai and Demodex cornei. Demodex species is a parasitic mite of the skin of dogs of the genus Demodex of the order Acarina and family Demodecidae. Demodex mites are normal flora localized in the skin of most apparently healthy dogs, and the disease arises when these mites overly multiply in the skin and hair follicles (Gortel, 2006; Dimri et al., 2008). Clinically, the disease has two forms, localized and generalized; the latter has more serious outcomes, whereas the former presents with a more favorable prognosis (Kumar et al., 2015). Clinical picture of the disease is usually associated with erythema, pustules, crusts, hyperkeratosis, and alopecia with secondary pyoderma as a frequent complication. The swiftest means for the diagnosis of canine demodicosis is a microscopic examination of skin scraping as it is both simple and confirmatory (Mederle et al., 2010; Paterson et al., 2009).

Canine demodicosis is an intricate infection, postulated to involve several immunologic and genetic components playing an integral role in its pathogenesis (Paterson et al., 2009). The level of C-reactive protein, one of the acute-phase proteins associated with non-specific inflammatory reaction in consequence to tissue injury, is believed to increase in canine demodicosis; however, there are limited data available about this. Albumin is classified as a negative acute-phase proteins as it is expected to decrease during the course of an infection. Oxidative stress is a state, in which the production of free radicals surpasses the neutralizing ability of the antioxidant system with consequent tissue damage and possible disruption of molecular structures (Kumar et al., 2015). Oxidative stress is believed to play a role in numerous human allergic and inflammatory cutaneous infections (Okayama et al., 2005) and canine allergic dermatitis (Kubesy et al., 2017).

Localized demodicosis should not be treated, but the dog should be monitored for flare ups, for instance with veterinary visits taking place at 4-week intervals. Treatment for generalized demodicosis should be monitored clinically and microscopically every month until the second negative skin scraping. Miticidal therapy should be continued four weeks beyond the second set of negative monthlyscrapings to decrease the risk of a disease recurrence. In dogs with demodicosis, systemic antibiotics will typically not be needed and topical antibacterial therapy combined with good miticidal agents will be sufficient unless severe bacterial infection is present (Mueller et al., 2020).

2. Aetiology 

2.1 Mite characteristics

Canine demodicosis is caused mainly by Demodex canis, a parasitic mite of the skin of dogs of the genus Demodex, of the order Acarina and family Demodecidae, is a mite described as inhabiting commensal in hair follicles, sebaceous ducts and sebaceous glands of dogs, found in small amounts in healthy animals (Fondati et al., 2010). According to Scott et al., the transmission of this mite occurs by direct contact of the mother with the neonates during the first 3 days of breast-feeding (Scott et al., 2001).

In its life cycle, the mite D. canis presents as an egg, larvae, protonymph, nymph, and adult (male and female), where all stages of the life cycle can be found in microscopic analysis of skin scalings. The eggs in fusiform (length 81.5 ± 3.5 μm) hatch into small larvae (length 91 ± 5.9 μm) with three pairs of paws, next protonymphs (length of 130.7 ± 10.7 μm), then nymphs (length of 201.2 ± 21.9 μm) and finally evolve into adult mites with four pairs of legs, which commonly measure from 40 to 300 μm (Scott et al., 2001).

 2.2 Mite classification

Although the D. canis mite (Figure 1) is the most common species (Scott et al., 2001), two new species, D. injai (Figure 2) and D. cornei (Figure 3), have also been documented causing dermatological alterations in dogs. Rojas et al., comparing the three species described in dogs, revealed interrelated but distinct populations in which D. canis presented with elongated opisthosoma (ratio opisthosoma length/total length 0.59), and an absence of a band-like segmental plate between the fourth coxisternal plate and opisthosoma (de Rojas et al., 2012). A longer-bodied mite also was reported and named D. injai ("inja" being the Zulu name for "dog") (Hillier and Desch, 2002). The female adult mites were approximately 50% longer and males 100% longer than adult D. canis mites, respectively. A short-bodied mite was named D. cornei by some authors because it was supposedly found more superficially. Genetic comparisons revealed only one or two different species of Demodex in the dog: D. canis and D. injai (Rojas et al., 2012; Sastre et al., 2013). In the genetic studies, the short-bodied mite was considered to be a morphological variant of D. canis (Sastre et al., 2013).

Figure 1. D. canis in light and scanning electron microscopy. The length of mites varies between 150 and 285 μm. Similarly to other mites, the general structure of Demodex consists of the head, or gnathosoma, with its mouthparts (1), the trunk or idiosoma (2), and the extremities. The idiosoma includes the podosoma (2A), into which the legs are attached, and opistosoma (2B), distal to the legs. The elongated, cigar like idiosoma, ring-like segmentation of opisthosoma, and very short legs are characteristic Demodex features (Saari et al., 2018).

2.3 Morphology

Demodex mites are described as small, with elongated bodies, having four pairs of legs. The body is separated into three distinct tagma: the gnathosoma, the small anterior segment with a trapezoidal or rectangular shape, containing mouth parts; the podosoma, which contains reduced and slightly projected legs beyond the podosoma line; and the opisthosoma, the posterior segment, elongated and formed by cuticular striae (Izdebska and Fryderyk, 2011) (Figure 4). The morphobiological characteristics of the adult mite D. canis are similar in several studies. 

2.4 Life cycle

The life cycle of Demodex includes, apart from the adult mite, egg, larva, protonymph, and tritonymph stages. The most common estimate of the length of life cycle in literature is 3–4 weeks. The puppy is infected by the dam during the first days of life. The infestation is preceded by the multiplication of the mites on the dam’s skin (Figure 5). The mechanism, which accelerates the multiplication just before whelping, is not known. It is possible that prepartum hormonal or immunological changes somehow signal the mites about the impending arrival of puppies. Demodex have been found from the hair follicles of rostral area of as young as 16-h-old puppies. All life cycle stages of D. canis live in the follicles, more rarely in sebaceous glands. In cases of generalized demodicosis, mites can also be detected in lymph nodes and even visceral organs, but they are dead individuals transferred elsewhere in the body by blood or lymph circulation. Unsuccessful attempts have been made over the years to infect dogs via oral, intraperitoneal, and intra-tracheal routes. Keeping dogs with clinical demodicosis signs in contact with healthy dogs has not led to transmission of the infestation or at least the disease. The close contact between the dam and the puppy appears essential for Demodex. The mites are very common species specific commensal organisms for mammals, using the follicle contents, such as the host's cells, keratin, and sebum for nutrition. Most dogs harbor single, latent Demodex mites in their hair follicles, living in quiet seclusion. In some individuals and in some circumstances the mites can start to multiply uncontrollably, leading into the symptomatic of demodicosis (Saari et al., 2018).

Figure 5. Life cycle of D. canis: (1) the life cycle of Demodex includes, apart from the adult mite, egg, larva, and two nymphal stages; (2) the lifecycle happens in hair follicles. The puppy is infected by the dam during the first days of its life. The infestation is preceded by the multiplication of the mites on the dam’s skin (3). The mechanism, which accelerates the multiplication just before whelping, is not known. Most dogs harbor single, latent Demodex mites in their hair follicles, living in quiet seclusion. In some individuals and in some circumstances the mites can start to multiply uncontrollably, leading into the symptomatic demodicosis (Saari et al., 2018).

 3.History of disease

Since the first description of Demodex mites in 1842 by the French dermatologist Gustav Simon, more than 140 known species or subspecies have been described, parasitizing hair follicles or sebaceous glands in 11 orders of mammals. Since the first description of Demodex in the 19^th century, new Demodex species from very diverse mammals have been reported. This widespread occurrence of Demodex throughout the mammalian class suggests that the relationship is very ancient and that it was established at the beginning of the appearance of mammals on earth, when the first animals with hair follicles appeared. Amniotes, the ancestors of mammals, birds and reptiles, originated on islands in coal swamps over 300 million years ago, perhaps in pursuit of insects for food. For early amniotes, the adaptation to land from their amphibian ancestor was achieved by a major evolutionary innovation, i.e. the formation of the stratum corneum that prevented water loss from the skin and allowed them to move onto the land. Amniotes then evolved two different strategies to prevent water loss. In Sauropsid amniotes, the ancestors of reptiles and birds, an a-keratinized layer formed above the b-keratinized layer and became the major constituent of scales and feathers. In Theropsid amniotes, the ancestors of mammals, scales were lost and they developed protohairs, caused perhaps by a mutation leading to upregulation of a patterning trigger, such as b-catenin, that provided the necessary enhanced mechanical protection for the thin stratum corneum and provided thermoregulation. It is estimated that hairs appeared over 210 million years ago (Ferrer et al., 2014).

4. Epidemiology

4.1 Species, age and sex

D. canis mites are present in small numbers in the skin of most healthy dogs. Transmission occurs form bitch to pups in the first 3 days of life. Canine juvenile demodicosis (localized or generalized) in often first noted by 3-6 months of age. Many of these juvenile cases spontaneously resolve but the disease may persist into adulthood. Canine adult-onset demodicosis (which is usually generalized) occurs in middle aged to old dogs (4 years or older) and is associated with internal diseases and immunosuppression (Cote, 2010). Sex predilections are not noted with canine demodicosis (Anita Patel et al., 2008). 

4.2 Genetics and breed predisposition

Dogs with juvenile-onset generalized demodicosis, their siblings, and their parents should not be bred because a hereditary predisposition exists. Purebred dogs are predisposed for juvenile-onset demodicosis; several short coated breeds are over represented (e.g. American Staffordshire terriers, boxers, pit bull terriers, and sharpies) (Cote, 2010). 

4.3 Risk factors

Poorly characterized immunologic factors influenced by genetics. Concurrent immunosuppressive diseases, poor nursing care, bathing the dog with soapy water with many control substances reduces the disease resistance of the outer skin layer or treating skin disease conditions, internal injuries for dogs with drugs or treatments, improper drug treatment (Anita Patel et al., 2008).

4.4 Associated disorders

Canine generalized demodicosis is frequently complicated by pyoderma (Cote, 2010). Environmental factors such as a high humidity and ambient temperature are anecdotally discussed as leading to more severe clinical signs in the dog, although no scientific studies have been conducted to confirm this statement (Mueller et al., 2020). 

5. Pathogenesis 

The main pathogenic mechanisms in demodicosis are summarized in Table 1. The importance of each mechanism probably varies from species to species, and also in the different clinical forms of demodicosis. The disruption of the cutaneous barrier due to the physical and chemical effects of the proliferating mites is likely to be present in all forms. The rupture of the hair follicles is facilitated by the inflammatory reaction, which is histologically characterized in the dog by a mural folliculitis accompanied by injury to follicular keratinocytes. In the dog, the cells have been reported to be CD3+ and CD8+ T lymphocytes, and they are considered to be cytotoxic T cells, which may mediate the injury in the follicular epithelium. Once in the dermis, the released mites, together with hair fragments and keratin, induce a granulomatous reaction, with a variable degree of lymphocytic infiltrates (Caswell et al., 1995; Day, 1997). The granulomas have been associated with the resolution phase of the disease, when the clinical lesions regress. The presence of a strong hypersensitivity reaction against the mites has been documented in papulopustular rosacea. A similar hypersensitivity reaction to the mites has not been documented in the dog, but the presence of CD8+ lymphocytes in the inflammatory infiltrate could be an aberrant or exaggerated immune response to the mites or against keratinocytes and Langerhans cells presenting Demodex antigens. It has been demonstrated that Demodex mites can contain, transport and interact with bacteria of the cutaneous microbiome. In consequence, some of the lesions observed in demodicosis have been attributed to the interaction between Demodex and bacteria (Ferrer et al., 2014).

Table 1. Main pathogenic mechanisms in demodicosis (Ferrer et al., 2014)

In the dog, the association of demodicosis with pyoderma is well established and is probably the most severe consequence of demodicosis. Treatment with antibiotics is prescribed if the clinical signs or cytological examination of exudates are suggestive of pyoderma. However, it is not known whether, as in humans, Demodex mites induce a proliferation of Staphylococcus pseudintermedius, or rather if this bacteria simply takes advantage of the epidermal barrier rupture that occurs in canine demodicosis. Although some recent papers have questioned the importance of the bacterial infection in canine demodicosis, it would probably be helpful to investigate the changes in the skin microbiome associated with canine generalized demodicosis. Concluding remarks in the course of evolution, Demodex mites have shown a long parasitic parallelism with their mammalian hosts. The host’s immune system appears to detect and tolerate the presence of these mites and also has an inhibitory effect on mite proliferation. There is some evidence that chitin can be recognized by TLRs from keratinocytes; however, the exact immunological mechanism that controls mite populations in dogs are still unknown. The initial cause of the mite overgrowth in juvenile generalized canine demodicosis is also unknown. Preliminary genetic studies have detected an association of the disease phenotype with certain haplotypes, but more extensive genetic studies are clearly needed. Once the disease has developed in a dog, indicators of T-cell exhaustion, such as the low production of supportive/stimulatory cytokines (IL-2 and IL-21) and high levels of suppressive cytokines (IL-10 and transforming growth factor-b) along with low numbers of circulating CD4+ lymphocytes have been documented. Up to this point, our understanding of the disease biology is still limited. Future research should focus on the control of mite populations by the immune system, the initial cause of the mite overgrowth, and the genetic background and inheritance of canine juvenile generalized demodicosis (Ferrer et al., 2014).

It is still poorly known in which situations and through which mechanisms lead to disease. D. canis, a normally harmless commensal mite commonly found in healthy dogs, causes hairless skin patches in some dogs and, to some, a severe and sometimes fatal skin disease. It is acknowledged that the canine immune defense system is, despite the absence of clinical signs, aware of the presence of Demodex mites. Toll-like receptors in dermal cells recognize the mites’ chitin, but the subsequent immune reaction is usually that of tolerance. In some circumstances in young dogs, but also in adults with some generalized disease, Demodex mites start to multiply uncontrollably. When the number of mites in the hair follicles has grown, hairs detach simultaneously, creating bald skin areas. The immune defense responds, often limiting the multiplication of mites and facilitating new hair growth on the alopecic patches. This is the typical picture of localized demodicosis. Some dogs, due to the genetic deficiency of immune system, generalized disease, or immunosuppressive medication, fail to respond to the multiplication of mites. The situation leads to the exhaustion of T lymphocytes. As a result, the production of cytokines that maintain immune defense diminishes, while the production of immunosuppressive mediators increases. The host’s ability to regulate the mite population is severely limited. In addition, the mites invade new hair follicles and cause epithelial damage. As a result, the contents of the follicle are absorbed into skin. This causes a chronic and purulent foreign body type reaction with associated secondary bacterial infection. The situation may escalate into a severe dermatitis, generalized demodicosis. Bacteria, usually of the genus Bacillus living in the gut of the Demodex mites, may also contribute to the pathology of Demodex infestation (Ferrer et al., 2014).

6. Clinical signs of disease and pathology

In the dog, localized and generalized forms of demodicosis were differentiated on the basis that the vast majority of dogs with localized demodicosis went into spontaneous remission without treatment (Miller et al., 2013). However, the definition of localized demodicosis is subjective and thus different presentations are judged differently by different breeders and veterinarians. The reported lesion extent consistent with localized disease ranges from four lesions to 50% of the body surface. It is unknown whether the size of a lesion considered localized is influenced by the size of the dog or whether an area with inflammatory lesions such as papules, pustules (Figures 6 and 7), exudation, crusting and ulcers is comparable to an area characterized only by alopecia and comedones. This may make the differentiation of localized from generalized disease difficult in some individual cases (Mueller et al., 2020).

Clinical signs develop after mite proliferation has occurred; they depend on the degree of mite proliferation. Initially, there may be a noninflammatory hypotrichosis/alopecia and/or an inflammatory dermatitis with mild erythema, comedone formation, scaling and associated hypotrichosis/alopecia (Figures 8 and 9). The lesions may be focal or multifocal to coalescing involving large areas of the body. Follicular plugging, dilation and hyperpigmentation of hair follicular ostia may be present and when seen are a clinical clue for the disease. Pedal demodicosis commonly causes quite marked hyperpigmentation (of both follicles and surrounding skin) and may present with significant interdigital inflammation, oedema and pain. In more inflammatory presentations, follicular oriented papules may develop. Pruritus is generally not thought to be characteristic of milder presentations; however, it is more common if the short-bodied morphological variant of D. canis (Sivajothi et al., 2015) is present and/or if secondary bacterial infection develops. Follicular casts (scale adherent to the hair shafts) may be present (Mueller et al., 2020).

   With more severe or advanced disease (Figures 10, 11 and 12), secondary bacterial infection may lead to follicular pustules, furunculosis with scale, crust, exudation and ulceration with draining tracts. Severe, generalized pustular demodicosis may be painful and associated with hyper pigmentation, lymphadenopathy, lethargy and fever. In those severely affected dogs, septicaemia secondary to bacterial infection is possible and may even have a fatal outcome (Mueller et al., 2020). 

7.Diagnosis

7.1 Deep skin scrapings

Deep skin scrapings are considered to be the diagnostic tool of choice in most patients with suspected demodicosis (Mueller et al., 2017). Samples may be collected with curettes, spatulae, sharp or dull scalpel blades. Placing a drop of mineral oil on the sampling instrument or directly on the skin is helpful for better adherence of the sampled debris to the instrument. Multiple scrapings of approximately 1cm² of affected skin should be performed in the direction of the hair growth and importantly the skin should be squeezed constantly or intermittently during scraping to extrude the mites from the depth of the follicles to the surface. Squeezing the skin has been shown to increase the number of mites found. Primary lesions such as follicular papules and pustules should be selected in order to obtain the best yield. If at early onset papules and pustules are not present, erythematous, alopecic areas should be chosen. Ulcerated areas are not suitable as it is less likely to find parasites in such areas. The skin is scraped until capillary bleeding occurs indicating sufficient depth of the scraping. The gathered debris should be of reddish to brownish colour, indicating sufficient material. If necessary in a long- or medium-haired dog, lightly clipping the area to be scraped (in the direction of hair growth) will minimize the loss of the scraped material into the surrounding hair. Debris then is transferred to a slide, mixed with mineral or paraffin oil and examined with a cover slip under the microscope at low magnification (overall x40 or x100). Recognition of mites is easier with a lowered microscope condenser and decreased light to increase the contrast in the microscope field. Specimens should be evaluated immediately, as anecdotally mite deterioration may occur making accurate identification of numbers and stages more difficult with time. As Demodex mites are part of the normal micro-fauna, one mite identified on several deep skin scrapings could be a normal but uncommon finding. However, more than one mite is strongly suggestive of clinical demodicosis. If only one mite is found in a dog with compatible clinical signs, further skin scrapings should be performed to confirm the diagnosis. Different life stages (eggs, larvae, nymphs and adults) and their numbers should be recorded and compared from the same sites at each visit to objectively measure the treatment success (Mueller et al., 2020).

Trichograms

Trichograms have been reported as an alternative to deep skin scrapings and are particularly useful in areas that are difficult to scrape, such as periocular and interdigital areas (Beco et al., 2007). An area of 1 cm² should be plucked with forceps in the direction of the hair growth and placed in a drop of mineral or paraffin oil on a slide. The use of a coverslip greatly facilitates thorough and rapid inspection of the specimen. To increase the chance of a positive trichogram, a large number of hairs (50 –100) should be plucked, if possible. When performed properly, trichograms have a high diagnostic yield (Beco et al., 2007). However, negative trichograms should be followed by deep skin scrapings before ruling out demodicosis. Positive trichograms in healthy dogs are rare (Fondati et al., 2010).

Tape strips (“Scotch tape TM tests”)

Tape strips also have been reported as an excellent diagnostic method for canine demodicosis. While squeezing the skin, the acetate tape is pressed onto the skin with the sticky surface down. Although this technique initially was reported to be more sensitive than deep skin scrapings follow-up studies have shown contradicting results (Mueller et al., 2020).

Other methods of mite detection

Direct examination of the exudate from pustules or draining tracts may reveal mites in some cases. Specimens can be collected by squeezing the exudate onto a glass slide, and visualized by adding mineral oil and a coverslip. In one study, exudate was collected from dogs showing exudative lesions with the blunt side of a second scalpel blade after gently removing the crusts and squeezing the lesion (Saridomichelakis et al., 2007). In this particular study, the exudate sampling was compared to deep skin scrapings and trichograms and was positive in all dogs sampled. However, this technique is only possible in dogs with more severe forms of demodicosis (Mueller et al., 2020).

Cytological specimens stained with commercial Romanowsky stains also may reveal Demodex mites (more easily recognized with the condenser lowered for searching). Although this is not a very sensitive method for the diagnosis, it is not uncommon to find mites on the evaluation of cytological samples of dogs with exudative forms of demodicosis (Mueller et al., 2020).

Diagnosing bacterial infections

Frequently, generalized demodicosis is associated with secondary bacterial infections. Particularly in severe cases involving furunculosis, a bacterial septicaemia is possible. When clinical signs of possible bacterial infection such as pustules or draining tracts are present, an impression smear should be obtained, stained and evaluated for an increased number and/or intracellular location of bacterial organisms. Most commonly, Staphylococcus pseudintermedius will be present, but in some patients, particularly those with furunculosis, Gram-negative rods such as Escherichia coli or Pseudomonas aeruginosa may dominate. For these cases, a culture and susceptibility testing is indicated (Mueller et al., 2020).

8.Treatment

How demodicosis is treated depends on whether the disease is localized or generalized, and whether it is of the juvenile or adult onset type. About 90% of dogs are cured without treatment thanks to their own immune defense. Localized demodicosis should not be treated, but the dog should be monitored for flare ups, for instance with veterinary visits taking place at 4-week intervals. It should be noted that a dog that has visited the veterinarian for single hairless patch and has not been treated may later develop more alopecic skin patches. The regeneration of fur on bald skin sites may take up to several months. Therapy is only initiated if the diagnosed skin condition emerges to generalized demodicosis. A long-term treatment, often lasting for months, is always required for generalized demodicosis. In the past, amitraz was the most frequently used drug. Amitraz bathing is, however, very tedious, and the treatment has been mostly replaced with systemically acting substances. Most treatment regimens are based on the use of macrocyclic lactones, for example, milbemycin oxime, ivermectin, moxidectin, or doramectin. Drugs of isoxazoline group have also shown themselves to be very effective against demodicosis. The duration of treatment depends on the case. Scrape samples are taken in about 4-week intervals during treatment and the follow-up. Treatment can be terminated when the skin is clearly recovered and the samples are free of Demodex mites in two successive monthly analyses. A bitch with demodicosis should be neutered as part of the treatment, because cycling is apparently associated with relapse risk, especially in association of pseudopregnancy. A case of adult-onset demodicosis is treated in the same manner as a juvenile disease, but it is important to find the factors making the dog susceptible to demodicosis and control them as well as possible.

CHECK OUT THE LIST OF VEMEDIM PRODUCT TO TREAT FOR CANINE DEMODICOSIS IN PETS

No.	Name of product	Ingredients	Image
1	Domax	Doramectin 10 m
2	Anti- Derm	Benzoyl peroxide 50 mg Exp.qs  1 g
3	Fronil spot	Fipronil 10 % w/v Non-aqueous vehicle qs……….....................to 100 %

9. Control and prevention

To prevent your dog from getting demodicosis, it is important to note the following points: i) control mite should be made by frequently clean the dog's place (2 times a week or more) and particular attention should be given to places where the animals sleep; ii) disinfect dog toys to avoid carrying pathogens; iii) deworming and treat ticks periodically. Use of isoxazolines may offer advantage of parasite control for Demodex along with prevention of other parasitic diseases including fleas, ticks, ear mites, etc; iv) a reasonable dog diet, vitamin supplements, adequate nutrition for dogs. Some studies have shown that a weak immune system is a favorable condition for demodicosis infection. 

HIGHLY RECOMMEND PREVENTION PRODCUTS FROM CANINE DEMODICOSIS IN PETS

Name of Product	Benefits	Ingredients	Image
Skin care	Medicated shampoo with chlorhexidine digluconate. Anti itching and deodorizing. Treatment of dermatitis.	Chlorhexidine digluconate 31.2 mg Exp.qs 1 ml
Micona Shampoo	Antifungal and antibacterial shampoo for dogs	Chlorhexidine digluconate 20 mg Miconazole nitrate 20 mg
Micona Spray	Treatment for Folliculitis, Dermatitis and Fungal infection on skin	Miconazole nitrate 20 mg Excipients 1ml

References 

Anita Patel, B. V. M., & Forsythe, P. J. (2008). Saunders solutions in veterinary practice: small animal dermatology. Elsevier Health Sciences.

Cote, E. (2010). Clinical veterinary advisor-E-book: Dogs and cats. Elsevier Health Sciences.

Day, M. J. (1997). An immunohistochemical study of the lesions of demodicosis in the dog. Journal of comparative pathology, 116(2), 203-216.

Ferrer, L., Ravera, I., & Silbermayr, K. (2014). Immunology and pathogenesis of canine demodicosis. Veterinary Dermatology, 25(5), 427-e65.

Mederle, N., Dărăbuş, G., Oprescu, I., Morariu, S., Ilie, M., Indre, D. and Mederle, O. (2010) Diagnosis of canine demodicosis. Sci. Parasitol., 11(1): 20-23. 

Mueller, R. S., Rosenkrantz, W., Bensignor, E., Karaś‐Tęcza, J., Paterson, T., & Shipstone, M. A. (2020). Diagnosis and treatment of demodicosis in dogs and cats: Clinical consensus guidelines of the World Association for Veterinary Dermatology. Veterinary dermatology, 31(1), 4-e2.

Saari, S., Näreaho, A., & Nikander, S. (2018). Canine parasites and parasitic diseases. Academic press.

Salem, N. Y., Abdel-Saeed, H., Farag, H. S., & Ghandour, R. A. (2020). Canine demodicosis: Hematological and biochemical alterations. Veterinary world, 13(1), 68.

Sousa, V. R. F., Gasparetto, N. D., & Almeida, A. B. (2019). Clinical and immuno-pathology aspects of canine demodicosis. In Parasitology and Microbiology Research. IntechOpen.

Scott, D.W., Miller, W.M. and Griffin, C.E. (2001) Parasitic skin diseases. In: Di Berardino, C., editors.

Sivajothi, S., Reddy, B.S. and Rayulu, V.C. (2015) Demodicosis caused by Demodex canis and Demodex cornei in dogs. J. Parasit. Dis., 39(4): 673-676. 

Weese, J. S., & Michelle, E. (2019). A color handbook: infectious diseases of the dog and cat: A color handbook.