Sarcoptic Mange

Also Known As: Sarcoptes scabiei var. canis, Canine scabies 

Transmission or Cause: Canine scabies is highly contagious. Transmission occurs through direct contact with a carrier animal, or when a mite falls off the skin of a carrier and survives in the environment long enough for it to infest a new host animal. At 50 - 59 F, mites can survive between four to 21 days in the environment without a host. At room temperature (68 - 77 F), mites can survive for two to six days. Affected Animals: Dogs, coyotes, foxes, (humans, cats and other mammals can be transiently infected). 

Overview: Sarcoptic mange is one of the most uncomfortable skin diseases that a dog can contract. Highly contagious, sarcoptic mange is caused by a mite called Sarcoptes scabeie var. canis and is transmissible to humans. These mites burrow into a host animal’s skin, causing scaling, yellowish crust, hair matting and loss, and severe itching. Some dogs never develop the classic skin lesions, but will itch constantly year round. Often, animals with this condition will be misdiagnosed as having allergies. Diagnosis can be very difficult because the mites frequently are not found on skin scrapings. Thus, treatment frequently is based on the suspicion of scabies, rather than a definitive diagnosis. Generally, topical dips are used for treatment. Injectable and oral medications are available, but certain breeds can have a fatal sensitivity to the medication. A veterinarian should be consulted about the proper course of treatment. The prognosis for sarcoptic mange is excellent with proper treatment. Symptoms: Severe, constant itching at any time of year is a classic symptom of sarcoptic mange. Areas with less hair, such as the earflaps, elbows, hocks, ventral abdomen, chest, and legs, are affected most commonly. The mites cause hair loss, a reddened rash, and yellowish crusts to form on the skin in affected areas. Typically the ear margins and elbows are affected most severely. The ear margins tend to have thickened, crusty material on the tips and yellow scales. The animal may develop a secondary skin infection and severe scratches from the trauma of constantly scratching. The lymph nodes also may swell as a result of mite related inflammation. Sarcoptic 

Description: Canine scabies is caused by a mite called Sarcoptes scabiei var. Canis. Although extremely small, these mites can cause severe itching and skin irritation that will decrease a dog’s quality of life significantly. The female mites dig into the superficial layers of the skin to lay their eggs. Once the eggs hatch, the larvae migrate nearby and then dig deeper into the skin to mature into adults. This process causes severe inflammation, irritation, itching, and rashes. With a 21-day life cycle, the mites can replicate quickly, causing a rapid increase in numbers and more skin irritation over larger areas. The mites can be passed to other animals, such as coyotes, foxes, and (transiently) humans. People who have acquired mites will develop itchy red bumps on their body. These lesions last for approximately two weeks, after which they usually disappear on their own. Repeated contact with the affected animal can cause the lesions to remain for long periods of time. A medical dermatologist should be consulted about any human skin lesions or questions about mites. 

Diagnosis: A definitive diagnosis of sarcoptic mange is often difficult. Several skin scrapes typically are taken and then examined under a microscope. Unfortunately, it is often difficult to detect mites, especially if the animal has had mites for a long time or has had several recent baths or dips. Other tests can be used to aid in a diagnosis, such as the pinnal-pedal reflex test. This test is given by rubbing the ear margin, or pinna, between the fingers and watching to see if the dog attempts to scratch the ear with its hind leg. If it does, then scabies is the presumptive diagnosis. Generally, if scabies is suspected, treatment should begin immediately. A prompt response to therapy, such as a decrease in itching, generally means the assumption of sarcoptic mange was correct. Prognosis: With proper treatment and prevention, the prognosis for a cure is excellent. 

Treatment: For dogs that have thick crusts or a thick hair coat, treatment begins by clipping the hair from the affected area. Then, an anti-seborrheic shampoo that breaks down and removes crusts, skin oil, and debris is applied. Next, a parasiticidal dip is applied to the entire body, including the face and ears. The dip should not be allowed to get into the eyes. The dip typically is used once a week for at least four to six weeks. The entire environment, including all animals and objects that have come into contact with a dog that has scabies, should be washed thoroughly and disinfected. Other treatments involve the use of an injectable or oral medication called ivermectin. Although this medication is a highly effective and common treatment, this use is considered extra-label; it should NOT be used in breeds such as collies, Shetland sheepdogs, Old English sheepdogs, and any herding dogs or their crosses. Side effects can cause death. The newest treatment for canine sarcoptic mange is selamectin, manufactured by Pfizer in the United States as Revolution. This topical parasiticide is effective in treating a number of different parasitic infestations in dogs and cats. For dogs with scabies, the treatment is applied topically, then repeated 2-4 weeks later. All dogs that have come into contact with an affected animal need to be treated as well. A veterinarian should be consulted about the most appropriate treatment plan. People with suspicious lesions should consult a medical dermatologist for evaluation and treatment. 

Prevention: The best way to prevent transmission is to avoid any contact with animals or the environment of any animal that may be carrying scabies. All boarding facilities, grooming equipment, and bedding materials should be washed thoroughly and disinfected on a regular basis.

*there are newer treatments since this handout was printed and we are currently doing updates.  A couple new treatmetns are from the Isoxazoline class - two that we use are Bravecto and Nexgard.

What is RingWorm?

What is RingWorm? 

Also Known As: Dermatophytosis, Microsporum canis, Trichophyton mentagrophytes, Microsporum gypseum, fungal infection.

Patient fluorescing under black light (woods lamp)

Transmission or Cause: Ringworm is transmitted from the environment to the animal. The fungus can infect the hair, nails, or skin and then be passed via the infected hair or scales of the skin to another animal. All bedding materials, combs, clippers, cages or any other objects with which an infected animal comes into contact become potential sources of infection. Other sources of infection include soil and rodents. Risk factors include poor nutrition, poor hygiene, and housing situations in which a large number of animals are closely grouped together. In addition, there is an increased risk for animals that are immunocompromised due to disease or immunosuppressive medications.

 hairs fluorescing under woods lamp

Affected Animals: Dogs, cats, humans, horses, cows, and other mammals. Ringworm can be transmitted between humans and animals. Overview: The fungal skin disease dermatophytosis has come to be called ringworm because of the appearance of the skin lesion that characteristically occurs with this disorder: a circular area of hair loss with a red, raised outer rim. These lesions result from an inflammatory reaction to the fungus. Most often, dogs and cats are infected by the Microsporum canis fungus, but other types of fungi cause ringworm infections as well. Cats, especially longhaired breeds, have a more generalized form of infection than dogs. These animals can be chronic carriers of a fungus even though they may not show any signs of infection themselves. Ringworm fungi can be transmitted to humans; therefore, owners of infected animals should consider quarantining the pet indoors until the infection is cured. Precautions should be taken while treating animals in order to prevent human infection and environmental contamination. Symptoms: Hair loss that is patchy or circular may be noted. Increased scales, reddened skin, bumps or pimples, darkened skin tone, and itching may be present. The face, ears, feet, and tail are the most commonly affected areas.

DTM plate with white, fungal growth

Description: Ringworm is an infection by a fungus that most often affects the hair, nails, and superficial layers of the skin. The most commonly noted fungal types seen in cats and dogs are Microsporum canis, Trichophyton mentagrophytes, and Microsporum gypseum. Animals can come into contact with infective fungal spores in the indoor or outdoor environment. Contaminated soil is a common source of infection, as are other animals infested with ringworm. Not all animals that are exposed to fungal spores develop a fungal infection, and if an infection does occur, the dog or cat may not show clinical signs of the disease but instead serve as asymptomatic carriers. The classic clinical sign of ringworm is the circular patch of hair loss with a red ring of inflammation. However, not all animals infected by ringworm will have this type of lesion. In fact, because the symptoms of this disease can vary greatly, ringworm should be considered as a possible cause of skin disease in any eruptive skin disorder. Although most healthy dogs and cats can rid themselves of a fungal infection on their own, some cases can be very frustrating to cure. The asymptomatic carrier state can complicate matters. Since the presence of disease is hidden in these cases, owners will not know to take precautionary measures to protect against the spread of infection. Animals that do not respond to treatment, especially those living in multiple-cat households, should be referred to a veterinary dermatologist or specialist.

Fungal hyphae different power level

Diagnosis: Following a thorough history and physical exam, testing will be performed to rule out other skin diseases that have similar signs, such as a bacterial skin infection and skin mite infestation. A special light, called a Wood’s lamp, can be used as a crude screening test for ringworm. Unfortunately, only 50 percent of a specific type of ringworm called Microsporum canis will fluoresce within the animal’s fur with the characteristic apple green color. Therefore, a negative result from a Wood’s lamp does not rule out the possibility of ringworm. A more reliable way to diagnose ringworm is to conduct a fungal culture on hairs taken from around the skin lesions by plucking them with a clean instrument or brushing them with a new toothbrush. In order to identify the source of the infection, the fungal growth is evaluated under a microscope to determine the type of fungus present. This assessment of the material subsequent to its growth in a medium will rule out false positives that would otherwise be caused by environmental contaminants. The veterinarian may evaluate plucked hairs under a microscope to look for evidence of fungal units associated with the hair shaft. However, this test is more time-consuming and only carries a 40 to 70 percent success rate in detecting a ringworm infection. In animals with severe skin abnormalities, skin biopsies may be obtained. Although a skin biopsy can indicate a true fungal infection of the skin as opposed to a temporary presence, this procedure offers a less reliable diagnosis than a fungal culture. Often, this test is performed when the skin lesions are impossible to culture for ringworm.

Prognosis: Most healthy animals are capable of clearing a fungal infection on their own, but this process takes months. Because of the zoonotic potential of the disease, medical treatment should be used in order to expedite the elimination of ringworm and to decrease the contamination of the environment with infective fungal spores.

microscopic view of fungal hyphae

Treatment: Because ringworm is infectious, animals with the disease should be quarantined within the owner’s home until the disorder can be cured. All infected animals or asymptomatic carriers within the household should receive topical therapy, which may include clipping down the hair and applying an antifungal ointment to the skin or shampooing and dipping the entire dog or cat in medicated products. The examining veterinarian will recommend the best approach depending on the location of the lesions. Topical treatment is continued until a negative fungal culture is obtained. Animals that do not appear to respond to topical treatment within two to four weeks may be given supplemental oral drug treatment in order to eradicate the infection more quickly. The most commonly used oral antifungal medication is griseofulvin, but some fungal infections may be resistant to it. Also, some animals, especially cats, cannot tolerate griseofulvin and may develop a serious side effect of fatal bone marrow suppression. Thus, serial complete blood count tests are performed on cats taking this drug to watch for evidence of bone marrow problems. Also, cats with the feline immunodeficiency virus should not be given this drug. Ketoconazole, itraconazole and fluconaole are also drugs used for the treatment of ringworm, as an alternative to griseofulvin for animals that cannot tolerate this medication, and because of their comparative safety and good efficacy, they are becoming the preferred medications for treatment of dermatophytosis. Periodic bloodwork to check liver function may be monitored in animals receiving long-term ketoconazole and itraconazole. Recently, terbinafine has also been used with success in selected cases of dermatophytosis in animals. A vaccination against Microsporum canis has been developed for cats, but the safety and efficacy of this vaccination still needs to be researched. The use of the vaccine may be recommended in frustrating cases of ringworm infection. Infections can be very difficult to eradicate in multiple-cat households or breeding facilities and often require the consultation of a veterinary dermatologist. Humans should wear gloves while treating the infected animal and follow the recommended protocol for avoiding infection, including a thorough disinfection of the indoor environment. If human infection does occur, prompt medical attention is advised.

Ringworm articles by Dr. Schick:

Client Ringworm Handout by Dr. Schick

Don't let ringworm run rings around your veterinary patients

Cat Flea

From a #cat in #Arizona! Yes we have #FLEAS in Arizona! 😻🐜🐶

What prevention does your cat/dog get?

#catfleas #dogfleas #fleas #bugs #dermatologyforanimals #dermvet #dermvettech

Cat Fleas are small, wingless insects that feed on animal blood. Besides being a nuisance, they can also transmit diseases and cause allergies or anemia. There are more than 2,200 species of fleas recognized worldwide. In North America, only a few species commonly infest house pets. Two common species of flea are the cat flea (Ctenocephalides felis) and the dog flea (Ctenocephalides canis). However, most of the fleas found on both dogs and cats are cat fleas.

How can I control fleas?

Also Known As: Flea bite hypersensitivity 

Transmission or Cause: When a flea sucks blood from a pet, it passes its saliva into the animal’s skin. Animals that are allergic to flea allergen will experience swelling, irritation, and itchiness. When the animal scratches the bites, further trauma to the skin lesions, hair loss, and more intense itchiness will result. A single flea bite can cause these symptoms in an allergic pet; animals without this allergy must be bitten many more times before their skin becomes irritated.

Affected Animals: Any breed or sex of dog can be affected. The average age for flea allergy is three to five years. Cats also can be allergic to fleas. 

Overview: Animals that have flea allergy dermatitis are hypersensitive to the saliva a flea passes into the skin when it bites. The bite from a single flea will have a minimal affect on a normal animal, but animals with flea allergy will experience immediate itching, redness and swelling. It is the animals themselves, and not the fleas, that typically do the worst damage. When an animal scratches its fleabites excessively, hair loss and skin abrasions can result. Some animals will develop circular, red, painful sores called hot spots that can occur anywhere on the skin, but commonly are seen along the back and tail base. The most common allergic skin disorder, flea allergy only can be resolved by preventing the animal from being bitten by the flea and removing all the fleas from the animal’s environment. There are medications available, however, that will alleviate the itching and discomfort until complete flea control is achieved. 

Symptoms: Common findings in an animal that is allergic to fleas include increased scratching or itchiness, loss of hair, hairs that appear broken, crusts and erosions of the skin, and pimple-like bumps. Thickened skin with darkened areas can be seen in severe cases. Fleas or flea feces, which can be difficult to detect, indicate the presence of fleas. Hot spots sometimes can be seen along the dog’s back and tail base. These sores are usually circular, red, oozing, and very painful, often requiring medical attention. 

Description: Flea allergy is the most common allergic skin disorder, affecting animals with an abnormal sensitivity to the saliva a flea injects into the skin when it takes a blood meal. In reaction to flea allergen, allergic animals will have inflammation and irritation of their skin, not to mention intense itchiness. Hair loss and skin lesions can result when an animal scratches or bites its irritated skin. The problem may last year-round in warm climates or in flea-infested indoor environments. In regions with cold winters, the allergy will appear seasonally during the warm months of the year. 

Treatment of flea allergy requires eliminating the fleas from the animal, other pets, and the surroundings. Various medications can provide temporary relief of itching for severely affected animals until flea control is achieved. How can I control fleas? How can I control fleas?  It may be difficult to detect fleas on a pet, but brushing it over a white sheet may help: flea feces, a dark, black material, that falls from the animal’s hair onto the sheet would suggest the presence of fleas. A flea comb also can be used to look for the feces or the fleas themselves. Pets should be examined often if itching is noted. 

Diagnosis: The symptoms of flea allergy can mimic other disorders of the skin. Before concluding that an animal is allergic to fleas, the examining veterinarian first will attempt to rule out allergies to food and inhalants, internal parasites, drug reactions, hair follicle inflammation (folliculitis), fungal infection, and other topical parasites, all of which may have signs similar to an allergic reaction to fleas. A thorough history and physical exam will be required, during which the veterinarian will analyze the type and size of the skin lesions. It is often very beneficial for pets with suspected allergies to be tested for allergens that may be causing the animal to be itchy and uncomfortable. 

There are two common techniques that veterinarians can use to determine any underlying allergies to allergens such as fleas. One technique is called intradermal skin testing which requires the injection of different allergens into the skin. This usually is done by a veterinary dermatologist and may require sedation. The second technique involves taking a blood sample and sending it to a laboratory for allergy testing. This is called serologic allergy testing. There are varying opinions about serologic testing, so consultation with the examining veterinarian will be necessary. 

Prognosis: An animal with flea allergy dermatitis will always remain allergic to fleas. The severity of this allergy typically worsens as the pet ages. If fleas are eliminated from the animal’s environment, the pet will stop suffering the symptoms of flea allergy. If the response is incomplete but flea control has been achieved, the animal should be reevaluated by the veterinarian for concurrent allergies. 

Treatment: The goals of treatment are to alleviate the animal’s allergic reaction to fleas by preventing the flea from biting the animal and eliminating the fleas from the environment. It is very important that owners completely remove the fleas and their eggs from the animal’s environment. This involves the treatment of all household animals for fleas to prevent the allergic pet from becoming reinfested. There are many commercially available products that kill fleas both indoors and outdoors. Additional products have been designed for use on the animal. Professional pest extermination companies, which usually carry a satisfaction guarantee, are also an option. A veterinarian can customize a flea control program to meet an allergic pet’s individual needs. Therapy for the allergic reaction is based on the severity and history of the symptoms. Following an evaluation of the dog, the veterinarian may prescribe any of the following medications: topical treatments, medicated shampoos, steroids, antihistamines, antibiotics, and fatty acid supplements such as skin oil replacement. The examining veterinarian often will recommend a commercially available product that kills fleas on contact, before they have a chance to bite. These products are ideal in helping prevent further flea allergic reactions. The effectiveness of allergy shots, or hyposensitization, for treating flea bite hypersensitivity remains controversial. This method of treatment, prescribed by a veterinary dermatologist, usually is reserved as a final therapeutic step for severely afflicted animals not responding to strict flea control. Prevention: Prevent fleas from entering the household. If evidence of fleas is noted on the dog or on any other pets in the household, early intervention can stop the problem before the symptoms become severe.

https://www.merckvetmanual.com/…/skin-disorde…/fleas-of-cats

Visit the Disease info page on our website for more handouts about FLEAS

https://dermatologyforanimals.com/disease-information