What does a parasite rash look like on a dog
Rashes on Dogs
A rash (pyoderma) is usually a temporary outbreak of scaly, patchy, and sometimes swollen or bumpy skin that is often red and may be itchy.
A rash can occur on any part of your dogs body, but it pops up most often on the belly. A rash by itself is usually minor and often goes away on its own, but it can be a sign of a more serious situation. The cause of rashes on a dog can range from parasites to diabetes.
Heres what you should know about rashes on dogs, from what to look for to possible causes and their treatments.
What to Check For if Your Dog Has a Rash
If your dogs rash gets worse or does not go away after a week, take your dog to the vet to be examined.
With rashes on dogs, you may see:
Causes of Rashes on Dogs
A rash can occur anywhere on a dogs body. The location of the rash can provide some clues as to what health issue may have caused it:
Belly rash or underarm rash: A belly rash on a dog is one of the more common reasons pet parents take their dogs to the vet. Rashes also often appear in a dogs underarms, more accurately, the point where a dogs front and hind legs meet the chest or abdomen. These rashes have many causes:
Groin-area rash: Like a belly rash, a rash in your dogs groin area is often due to:
Paw rash: Known as pododermatitis, this is inflammation of the paws that can include a rash. Causes can include:
Diagnosing Rashes on Dogs
Your vet will give your dog a physical exam and ask questions about your dogs diet, current health issues, home environment, and other factors. To diagnose a rash, your veterinarian will perform a number of tests, depending on the suspected cause, including:
Allergy tests if an allergen is suspected. This may include a food elimination diet or intradermal allergy testing.
Skin scraping to look for mites, bacteria, fungus, or other potential causes.
Skin biopsy, where a piece of skin is examined at a pathology laboratory (done in cases of recurring infection or rash).
Blood profile to check for diseases such as thyroid issues (hypothyroidism) or Cushings disease
Treatment for Rashes on Dogs
To eliminate the rash and make sure it doesnt come back, your vet will need to find and treat any underlying medical condition thats causing it.
They may also recommend several treatments for the rash and related symptoms. These may include:
Grooming (such as brushing or cutting away hair)
Oatmeal baths
Medicated dog shampoo (containing antifungal or antibacterial ingredients)
Anti-itch and anti-inflammatory medications
Elizabethan collar or e-collar to prevent a dog from irritating hot spots by licking or biting
Epsom salt foot soaks if your dogs paws are inflamed. Follow your veterinarians instructions, as these can dry out the skin if used inappropriately. Do not allow your dog to drink the solution, which has high sodium levels.
Featured image: iStock.com/SeventyFour
Rashes on Dogs FAQs
What can I put on my dogs skin rash?
Depending on the cause and location of the rash (and accompanying symptoms), a veterinarian may recommend oatmeal baths, medicated dog shampoos, or medication to reduce itching and inflammation. Do not give your dog any medications without a veterinarians recommendation and guidance.
What does a rash look like on a dog?
Rashes can appear red, bumpy, inflamed, or like welts. There might be hair loss or hot spots, areas of skin that are inflamed and oozing.
What can cause skin rashes on dogs?
Causes of rash in dogs are numerous and range from allergies and insect bites, which are most common, to thyroid conditions and cancer.
References
- Smith, John. American Heartworm Society. Heartworm Basics. January 2020.
- Veterinary Partner. Pruritus Diagnostics in Dogs and Cats. October 2003.
- Brooks, Wendy. Veterinary Partner. Itch Relief for Dogs and Cats. January 2001.
- White, S.D. Merck Veterinary Manual. Hives and Rashes (Urticaria) in Dogs. June 2018.
Parasitic Worms of the Skin in Dogs
Dracunculus insignis is a species of roundworm found mainly in the connective tissue beneath the skin of the host's legs. They are known to infect raccoons, minks, and other animals, including dogs, in North America. Female worms can reach more than 1 foot (300 millimeters) in length. Male worms are tiny in comparison, around 0.8 inches (20 millimeters) long. These worms can produce skin ulcers on their hosts. When the ulcers touch water, the worms stick their heads out of the wounds in order tolay their long, thin-tailed larvae. The larvae then develop inside of another host, the water flea. Dogs can also become infected when they drink contaminated water or eat another host, such as a frog.
Signs of D. insignis worm infestation include snake-like, swollen tracks under the skin and crater-like red ulcers on the skins surface. These infections are rare, but have occasionally been found in dogs that have been around small lakes and shallow, stagnant water.
Veterinarians treat the infection by carefully and slowly extracting the parasites. Antiparasitic drugs of the miridazole or benzimidazole classes can also be useful.
In parts of Africa, Asia, and the Middle East, a guinea worm (Dracunculus medinensis) is a well-known parasite of humans that may also infest dogs and other animals.
Ringworm in Dogs
What is Ringworm in Dogs?
While the term ringworm may conjure up the image of a long, wriggly intestinal parasite, this is inaccurate, as ringworm is not actually a worm at all. Ringworm is a name that has long been used because of the circular itchy rash that typically appears on the skin of an infected animal. Ringworm is a fungal infection that can affect the skin, hair, or nails. The medical term for this type of infection is called dermatophytosis. The most common fungal organisms that can cause ringworm are Microsporum and Trichophyton. The fungus feeds on dead hair or skin cells.
While ringworm is most commonly found in cats, it can also be contracted by dogs and humans. It is highly contagious and zoonotic, meaning it can spread from pets to people and vice versa.
Symptoms of Ringworm in Dogs
In dogs, the areas usually affected by ringworm are the face, ears, tail, and feet. Symptoms generally include one or more of the following:
Circular areas of hair loss, often with a red and crusty edge
Broken hair and a poor hair coat
Dry, scaly skin or areas of excessive dandruff
Inflamed areas of skin
Darkened patches of skin
Itchiness, scratching, or excessive grooming
Inflamed nail beds or darkened or dry nails
Dry, brittle, or misshapen nails
Causes of Ringworm in Dogs
Most dogs with ringworm contract it from direct contact with an infected animal (likely a dog or cat) or human. It is possible for dogs to have the ringworm fungus on their body but show no external signs of the disease; however, they can still pass the disease on to humans or other animals.
Ringworm can also be passed on through contaminated objects such as brushes, dog beds, and toys, as well as surfaces that are difficult to clean, like rugs, wool, and wood.
Some types of ringworm fungi live in the soil, and a dog could contract ringworm by digging around in the dirt. This is especially true in warm and humid environments. The spores of the fungi that cause ringworm are quite hardy and can live in the environment for at least 18 months.
The types of dogs that become infected with ringworm tend to be those with weaker immune systems, such as very young or old dogs, as well as dogs with diseases that weaken their immune systems, or dogs that have recently come from long term stays at kennels or shelters. Boston Terriers, Yorkshire Terriers, and Russell Terriers are genetically more prone to ringworm infections than other breeds.
Dogs that have skin conditions are also predisposed to ringworm. The skin usually functions as a health protective barrier, but if a pet has an open wound, fresh scratches, fleas, or a chronic skin condition they are more susceptible to an infection.
Infection with ringworm occurs when spores attach to damaged skin. Lesions (abnormal areas) on the skin will typically appear about 1-3 weeks after exposure.
How Veterinarians Diagnose Ringworm in Dogs
There are a few procedures that your vet may use when diagnosing ringworm, the most common of which are a Woods lamp examination, a fungal culture, and a PCR test.
A Woods lamp emits long-wave ultraviolet light (a type of black light) to help detect bacteria. The fungus Microsporum canis (the most common cause of ringworm infections in pets) causes a chemical reaction when it attaches to hair follicles, causing them to glow when a Woods lamp shines. No fluorescence will be seen on a pet that is an asymptomatic carrier.
This bedside examination is effective in about 72% of M. canis cases with active skin lesions. Fluorescence usually becomes visible about 5-18 days after an infection takes hold. It is a great place to start when a vet is suspicious a dog may have ringworm.
A fungal culture (sometimes called a DTMdermatophyte test medium) is where a few hairs, scales, or scabs are collected and placed on a culture medium (a substance for growing microorganisms) and the contaminant is allowed to grow.
Your vet will then look at the growth under a microscope to determine if one of the fungal species that cause ringworm is present. Positive signs can show after 3-5 days, but final results can take 10-21 days. One benefit of this test is that it does not require an active skin lesion; any hair sample can be tested.
PCR (Polymerase Chain Reaction) testing is the newest way to diagnose ringworm. This test is also done on hairs and is specifically looking for fungal DNA (material with the funguss genetic information). The PCR test is much faster than a culture, and results are usually available in 3-5 days.
PCR is a great test for an initial diagnosis of ringworm; however, it is not suitable for follow-up testing to ensure that the ringworm has been fully cleared. This is because PCR testing looks for DNA but cannot distinguish whether the DNA is from living fungus. Fungal culture testing is usually the recommended follow-up test to make sure the infection is completely gone.
Treatment for Ringworm in Dogs
Ringworm is treatable and curableif all treatment, quarantine, and cleaning procedures are followed. Ringworm can be very stubborn, so it is important to be fully committed to the following procedures:
Quarantine
Ringworm is highly contagious, so the first thing to do when a ringworm infection is suspected is quarantine your dog. Try to keep your dog away from other pets and limit their contact with humans.
Ideally, have your dog in a room that can be easily cleaned like a large bathroom. A room with rugs or wood floors should not be used, as these are very difficult to clean.
Topical Treatments (applied to the body)
Bathing is a critical part of treatment as it will remove and kill the fungal spores that are on your dogs fur. This is helpful in preventing further environmental contamination and cross-contamination with other animals in the home since hairs that have been treated will not be infectious when shed.
There are two main types of topical treatments: Lime Sulfur dips and antifungal shampoos. Of these, Lime Sulfur dips are more effective. Lime Sulfur dips can be done at home or at your vet hospital. They are quite messy and odorous, so many pet owners elect to have this done at their vet's office.
Antifungal shampoos are often paired with a disinfectant like chlorhexidine, as they work well together to combat ringworm. These typically need to be used twice weekly.
Ointments or other topically applied medications have not been shown to be effective against ringworm infections.
Shaving dogs with very long coats is not recommended, because shaving can cause microtrauma (small injuries) to the skin, which can make the dog more susceptible to the infection.
Oral Treatments (Medications taken by mouth)
Oral medications clear the ringworm infection by making the fungus unable to reproduce and spread. In most cases it is recommended to use oral and topical measures together.
There are numerous different types of oral antifungals, with different costs and potential side effects (the most common are gastrointestinal/tummy related).
Your vet will work with you to find the right product and medication for your pet based on their health and diagnosis.
Decontamination Procedures
Infected pets are constantly shedding fungal spores into the environment. It is extremely important to isolate your dog and to disinfect all other areas of the house until a culture test is negative or your vet recommends stopping treatment. Otherwise, your dog could become reinfected with ringworm from the environment.
Thoroughly clean all areas that your dog has come into contact with, using an effective disinfectant such as a dilute (1:10) bleach solution, accelerated hydrogen peroxide, or a similar product. Bleach will not properly disinfect a dirty surface, so it is important to clean first, with an agent like liquid dish soap, and to disinfect second.
You will also want to vacuum and/or steam clean your floorsand dont forget to disinfect your vacuum afterwards. Items like dog beds that can be laundered should be run through a washing machine, twice, in hot water, preferably with bleach.
The area of your home in which your pet is confined should be cleaned twice weekly during treatment. When you are treating a pet at home, do your best to wear disposable gloves and be sure to wash your hands and clothing after handling an infected pet.
Recovery and Prevention of Ringworm in Dogs
It is important to note that pets can be silent carriers of ringworm. A carrier is a pet that is infected but not showing any signs. Because of this, once a pet has been diagnosed with ringworm, all other pets in the home should be tested.
Treatment generally continues for weeks to months and should not be stopped until follow-up testing shows that the fungal organisms are clear, and your vet directs instructions to stop. Ideally, to monitor the progression of the treatment, a fungal culture should be done every 2-3 weeks after starting treatment.
A person who is infected with ringworm can also give it to their pets. If you notice a red, ringed skin lesion on your skin, it is best to have your doctor, or a medical professional examine the area.
When taking in stray dogs or cats, it is important to keep them isolated from your pets until they have had a complete medical evaluation by a veterinarian.
Since ringworm can be present in soil, dont let your dog dig outside, especially if there is abundant wildlife living nearby, as they can be a source of infection.
Taking your dog to the vet for twice yearly exams is also helpful. Pets that have healthy skin are much less susceptible to ringworm.
Ringworm in Dogs FAQs
How contagious is ringworm from a dog to a human?
Unfortunately, ringworm can be highly contagious to humans. Those at highest risk are people with weaker immune systems such as young children, the elderly, pregnant women, and those on chemotherapy or other immunosuppressant medications.
Will ringworm in a dog go away on its own?
The technical answer is that it would most likely go away on its own after about 9-12 months, depending on the species of ringworm fungus and the strength of the dogs immune system. However, during this time the dog is infecting the environment, and potentially all the humans and other pets in the household could become infected. Most of your dogs hair would fall out, since ringworm feeds on the hairs and dead skin, leaving your dog's skin more susceptible to wounds and potential secondary infections.
How can I tell if my dog has ringworm?
Any type of skin disease can look like ringworm. If you notice your dog has a crusty lesion or circular area of hair loss with a ring of red skin, or any persistent skin damage that is not resolving, they should be examined by a veterinarian to evaluate them for treatment.
Are there home remedies to help dogs with ringworm?
There are many old wives tales about using household products to treat ringworm, but these are not effective and can be toxic to pets. There are some over-the-counter antifungal shampoos which can be helpful, but nonprescription medications are not always effective.
Featured Image: iStock.com/RuslanDashinsky
WRITTEN BY
Stephanie Howe, DVMVeterinarian
Dr. Stephanie Howe graduated from the University of Florida College of Veterinary Medicine in 2011, after receiving a Bachelorof Science...
