Interview with Dr. Tobin, DVM
Dr. Stephen Tobin is a holistic veterinarian who provides treatment using homeopathic herbs and nutrition. He speaks with us about his philosophy of animal care, pet nutrition, and his experience with the Longlife Program in the treatment of his patients.
How Does Longlife Treat Hot Spots?
Longlife for Dogs contains pure shark cartilage, specially processed for maximum absorption into the bloodstream by your dog’s digestive system. It contains Amino Acids and High Proteins, with natural Mucopolysaccharides. The anti-inflammatory properties of Longlife for Dogs help soothe irritated skin and remedy a host of skin diseases. A natural immune system booster, Longlife for Dogs promotes healing and good skin condition.
Causes of Hot Spots in Dogs
The majority of cases involve a natural portion of the skin called staphylococcus intermedius, which becomes pathogenic (disease causing) when the skin environment changes for any of a number of reasons. Other bacteria and microorganisms maybe involved, but some reports suggest that over 90% of cases have Staphylococcal involvement.
A hot spot starts because something irritates, itches, or causes inflammation of the dog’s skin. In cases of itching, the dog rubs, licks, or chews the site and exacerbates the problem. These sores can develop into severe problems in as short a time as an hour or two.
The most common irritants are probably fleas and allergies, which cause the itching that leads to the skin infection. Many other possible sources of irritation, such as tick bites, besetting, burrs, mats, mosquitoes, summer heat, and other problems, can contribute to the initial irritation that develops into a hot spot.
Symptoms of Hot Spots
The most common symptoms are itchiness, redness, often with pimples or scabs, and a bad odor. Surface pyodermas may show as areas of redness and irritation, often developing into raised, round scabs. Superficial pyodermas produce yellow spots which then break out into larger wheals and scabs. Deep pyoderma can make pets systemically ill and produce abscesses and oozing, inflamed channels in the skin surface. Certain areas may be particularly prone to infection. Interdigital areas, inside the ears, at the groin, and along the middle of the back are common infection sites. Other diseases, such as yeast infections, can look very similar, so if there isn’t a rapid resolution with home treatment, seek professional advice.
Subsets: Aside from depth of the infection, one can subdivide hot spots/skin afflictions/pyoderma by way of origin and manifestation.
Primary pyoderma: There is little doubt that occasionally pyoderma may develop spontaneously and for no obvious clinical reason, or idiopathically. As with arthritis, there is simply no known cause. The general consensus is that these dogs probably have a compromised immune system or a congenital factor affecting skin immune systems. The exact genetic nature of pyoderma remains a mystery.
Atopy in Dogs
Atopy: is a disorder by which dogs have a predisposition for developing antibodies to environmental allergens. Atopy is the most common disorder causing hypersensitive skin reaction in non-flea allergic patients presenting with dermatitis and accounts for up to 70 to 90% of all hypersensitive conditions. Although it has been found that up to 10% of dogs with atopy may also have food allergies, up to 80% of dogs diagnosed with food allergies also have atopy, thus accounting for the high rate of failure to treat food allergy patients through manipulation of diet alone.
Cause: Dogs that develop atopic dermatitis have a predisposition for excessive production of immunoglobin E (IgE) antibodies. IgE antibodies are believed to be the primary immune defense against parasitic organisms. However, in humans and other animals, including the dog, these antibodies are also responsible for producing allergic reactions. When a hypersensitive dog is first exposed to an environmental allergen, such as pollen, mold, or dander, its immune system will begin to produce high levels of IgE antibodies that will accumulate in the tissues of the body. (In humans, IgE is found predominantly in the respiratory and conjunctival mucus membranes, while in dogs, IgE antibodies locate predominantly to tissues comprising the skin.) When the dog is re-exposed to the same allergen at a later time, IgE antibodies bind to the allergen and activate the release of histamines (chemicals that attract other immune surveillance cells to the site of infection) from specialized, blood-derived immune cells called mast cells, which are involved in the inflammatory response. Histamine release results inreddened and itchy skin consistent with symptoms of dermatitis. In some instances, atopic dogs have been found to have non-reactive IgE antibodies, but demonstrated elevated levels of immunoglobin Gd (IgGd) antibodies. IgGd is a subset of IgG antibodies, a separate class of antibodies that predominantly circulates in the serum and is responsible for producing such conditions as anaphylactic reactions. Current studies are aimed at exploring the role of IgGd antibodies in the a topic disease process.
Symptoms of atopy: The most common symptom of atopy is pruritis(itching), usually beginning around the face and paws and in some cases eventually becoming more diffuse over other areas of the body, particularly the ears, armpits, elbows, and groin. Recurrent ear infections are present in up to 75% of dogs diagnosed with atopy. Skin lesions are not usually apparent, unless resulting from excessive scratching, but a raised, pustular rash with or without hair loss may occur as a result of secondary pyoderma. Some dogs may develop conjunctivitis.
Diagnosis: Because many other dermatologic disorders may present with similar symptoms to atopy, certain criteria have been established to select symptomatic patients for further in vitro testing and to identify the causative allergen:
- Member of a breed with a known predisposition for atopy
- Clinical symptoms manifesting between 6 months and 4 years of age
- Waxing and waning symptoms associated with seasonal changes
- Positive response to glucocorticoid treatment
Though symptoms during seasonal changes are the best indicator of atopy in a dog, a diagnosis of atopy should not be excluded in the absence of seasonal symptoms, since it has been found that up to 80% of dogs with atopy will demonstrate continual, year-round symptoms. When these criteria are met and other differential diagnoses are ruled out, then allergy testing to identify the responsible allergen(s)becomes the next consideration.
Principles of Canine Allergy Testing
In general, mixed allergen testing (combining antigens from different sources together, in the same way a human might be tested, say on his or her back) may be performed. Since the purpose of testing is to identify a specific allergen or allergens for immunotherapy, testing each allergen individually is the preferred method. Common testing allergens include: grasses, trees, shrubs, weeds, molds, house dust mite bodies, mite eggs, mite larvae, mite feces, fleas, ants, flies, cockroaches, mosquitoes, moths, feathers, nylon, wool, silk, and tobacco. Food allergen testing is rarely effective for identifying food-related allergens; therefore, food elimination testing is the preferred method for screening for food allergies (to be discussed in an article in the next series). Selection of allergens for the purpose of treating dogs with immunotherapy (hypo sensitization treatment) may be done either through intradermal testing or in vitro testing. Each method has its strengths and weaknesses in terms of laboratory analysis. With intradermal testing, a commercially available antigen is selected and injected under the skin and the site of the injection is observed for signs and intensity of an allergic response. Many dermatologists utilize intradermal testing because it has a high level of specificity and thus positive results are more likely to be true-positives. The main limitation with this test is the occurrence of false-negatives because of poor sensitivity associated with this form of allergen testing.
An alternative to intradermal testing is in vitro allergen testing. This second method requires reacting serum from the dog with a commercially-available antigen that has been bound to a solid substrate in a radioallergosorbent test(RAST)or enzyme-linked immunosorbent assay (ELISA), which measures the amount of IgE in the patient’s serum that binds to the allergen. This testis particularly useful in evaluating dogs that have already undergone or are continuing treatment with glucocorticoids (since these drugs will inhibit intradermal test reactions yielding false-negative results). However, in vitro allergen testing has a higher degree of non-specificity and, therefore, false-positive results. Recent modifications to methods of in vitro allergen testing by the Veterinary Allergy Reference Laboratory (VARL) have provided a means to increase the level of specificity of these in vitro tests aimed at detection of IgE through the use of monoclonal anti-IgE reagents. Additionally, this testing method also seems to provide comparable specificity while providing greater accuracy compared to intradermal testing for detecting insect-associated allergies.
Ectoparasites
These include, especially, fleas. Apart from the trauma and irritation of individual flea bites, many dogs develop an allergy to flea saliva, which causes generalized skin inflammation and can lead to pyoderma. A whole host of other afflictions, known as Parasitic Skin Disease, can result from ectoparasites.
Fleas: There are many types of fleas, but for dogs, it is often the cat flea that causes the problem. Fleas will not live or breed on humans, although they may bite us. They are dark brown, vertically flattened, and very fast moving. They breed in carpets and bedding, usually inside. Every adult female flea has the potential of laying up to 200 flea eggs per week inside a house, so it doesn’t take long for tens of thousands of fleas to develop. The flea egg falls to the floor, lies in a carpet or between the floor boards, hatches, and forms an organic scavenging pupa, which then forms a cocoon before emerging as the adult flea. The life cycle can take from two weeks to six months or more.
Flea prevention: We believe that the best anti-flea products are obtained directly from your veterinarian, when your pet has an active flea problem. However, you should try to prevent flea infestation before it starts. Once treatment starts, it is important to provide constant flea control, as a break of even a month will allow fleas to start breeding again in your household.
Determining the presence of fleas: To conduct a very simple test for the presence of fleas, start by placing a layer of damp tissue paper twice the size of the dog on a tabletop. Place the dog on the tissue paper and comb all areas of the coat, especially the middle of the back, onto the tissue paper. Then look for black/brown granules that absorb water and form a russet brown ring around the granules. These are flea dirts and indicate an active flea presence.
Life Cycle of Fleas: Dog fleas will lay their eggs on a pet in their close proximity. These develop into organically scavenging pupae in car pets and skirting boarding and, depending on climatic conditions, will develop via a cocoon phase into adult fleas between two weeks and six months after deposition. Movement in a room triggers the hatching of the cocoon larvae into the adult flea.
Other Flea-Caused Canine Skin Conditions
Ticks: These are common parasites of dogs that walk in long grass. They are able to spread some intracellular parasites. The bites can also cause local skin reactions, such as tick bite granuloma.
Cheyletiella: This is a mite that can live on the skin of dogs. It particularly likes the dorsal surfaces and will cause intense irritation and heavy scurfing and dandruff in limited areas, especially on the dorsum (upper surfaces) of the back.
Lice: These external parasites are becoming increasingly rare and are species specific. They are usually 1–2 mm in length and a faun to plum color. They will cause intense irritation on all body surfaces, especially over the body where areas of hair loss and skin inflammation may occur. Ear mites: Also known as Otodectes, these are common parasites of the ear canal of the dog which may cause intense irritation and excessive wax production. They often cause secondary irritation around the ear flaps.
In any case of pyoderma, assume fleas may play a role until proven otherwise.
Other Causes of Skin Irritation in Dogs and Cats
Dietary allergy: Not as common as people would like to believe, but occasionally seen in dogs because of a daily inclusion of beef, chicken, and wheat-based products in dog foods.
Skin trauma: Working dogs in particular will suffer occasional wounds when working in rough patches.
Seborrhoea: Seborrhoea can be idiopathic (developing from an unknown source, often congenital or inherited) or secondary to other factors (see below). The two primary presentations are:
Seborrhoea oleosa or oily seborrhoea: Oily seborrhoea is due to excessive production of skin oil, waxes, and skin cells. The coat takes on a matted look and a greasy feel, and oily dandruff clogs the base of the hairs. There is often a strong and unpleasant odor to the skin. Many dogs are pruritic(itchy) and nibble and rub themselves persistently, causing hair loss, inflammation, and secondary infections.
Seborrhoea sicca or dry seborrhoea: Dry seborrhoea is caused by an excessive production of skin cells. The coat takes on a dull look, with excessive scaling of the skin producing a heavy dandruff. These dogs are also pruritic and again may bite and nibble, setting up areas of inflammation and hair loss in which secondary infection may occur.
At-risk breeds: West Highland Terriers, Springer Spaniels, and German Shepherds appear to be at the greatest risk for congenital seborrhoea.
What to look for: There are many different sources:
- Allergies – Environmental, food allergies, contact, etc.
- Endocrine deficiencies – such as hypothyroidism. Defects in fat absorption or metabolism.
- Parasitic infections – Flea allergic dermatitis, sarcoptic and demodectic mange, harvest mites, cheyletiellamites.
- Fungus – Melassezia yeast is the most common.
- Dietary deficiencies – Protein, zinc, and vitamin A (unlikely with high-quality, complete dog foods).
Other lesions: Can be caused by furunculosis (often inherited)to “hot spots” due to excessive licking and scratching.
Principles of Allergy Testing
In general, mixed allergen testing (combining antigens from different sources together, in the same way a human might be tested, say on his or her back) maybe performed. Since the purpose of testing is to identify a specific allergen or allergens for immunotherapy, testing each allergen individually is the preferred method.
Common Pet Allergens
Common testing allergens include: grasses, trees, shrubs, weeds, molds, house dust mite bodies, mite eggs, mite larvae, mite feces, fleas, ants, flies, cockroaches, mosquitoes, moths, feathers, nylon, wool, silk, and tobacco. Food allergen testing is rarely effective for identifying food-related allergens; therefore, food elimination testing is the preferred method for screening for food allergies.
Selection of allergens for the purpose of treating dogs with immunotherapy(hypo sensitization treatment) may be done either through intradermal testing or in vitro testing. Each method has its strengths and weaknesses in terms of laboratory analysis.
Intradermal Testing
With intradermal testing, a commercially available antigen is selected and injected under the skin and the site of the injection is observed for signs and intensity of an allergic response. Many dermatologists utilize intradermal testing because it has a high level of specificity and thus positive results are more likely to be true-positives. The main limitation with this testis the occurrence of false-negatives because of poor sensitivity associated with this form of allergen testing.
In Vitro Allergen Testing
An alternative to intradermal testing is in vitro allergen testing. This second method requires reacting serum from the dog with a commercially-available antigen that has been bound to a solid substrate in a radioallergosorbent test (RAST)or enzyme-linked immunosorbent assay (ELISA), which measures the amount of IgE in the patient’s serum that binds to the allergen. This test is particularly useful in evaluating dogs that have already undergone or are continuing treatment with glucocorticoids (since these drugs will inhibit intradermal test reactions yielding false-negative results). However, in vitro allergen testing has a higher degree of non-specificity and, therefore, false-positive results. Recent modifications to methods of in vitro allergen testing by the Veterinary Allergy Reference Laboratory(VARL) have provided a means to increase the level of specificity of these invitro tests aimed at detection of IgE through the use of monoclonal anti-IgE reagents. Additionally, this testing method also seems to provide comparable specificity while providing greater accuracy compared to intradermal testing for detecting insect-associated allergies.
Long-Term Effects and Prevention of Hot Spots
The natural reaction of the dog (biting and scratching) will worsen the affliction, which only encourages more biting and scratching. This cycle can go on rapidly and spread widely. The descent to weepy, almost syrupy skin can occur very rapidly and be quite frightening. What is then seen is an area of hair loss with very red skin that may be exuding serum. In some cases there isn’t much hair loss but the skin gets crusty or scabbed anyway.
The best action here is prevention. Keep your dog free of fleas. Groom and bathe your dog as necessary to keep the hair coat in good condition. Limit sources of irritation to the best of your ability. If allergies are a problem for your dog, work with the vet to control the itching they cause. Though these measures may not prevent hot spots in all dogs, they will certainly help in many cases.