What is an allergy and what are the symptoms?
An allergy is an over-reaction of the immune system to a particular substance called an allergen. Most allergens are proteins from plants, insects, animals, or foods.
In the dog, the most common symptom associated with allergies is itching of the skin. This itching may be in one area or all over the body. In some cases, the symptoms involve the respiratory signs like coughing, sneezing, and wheezing. Sometimes, there may be runny discharge from the eyes or nose. In other cases, the allergic symptoms affect the digestive system resulting in vomiting and diarrhea.
How common are allergies in dogs?
Unfortunately, allergies are quite common in dogs of all breeds and backgrounds. The majority of affected dogs show signs after the age of one or two.
What are the common allergy-causing substances (allergens)?
A vast number of substances can act as allergens. Most are proteins of insect, plant, or animal origin. Examples of common allergens are pollens, mold spores, dust mites, shed skin cells (similar to pet allergies in humans), insect proteins such as flea saliva, and some medications.
What are the different types of allergy?
There are four common types of allergies: Flea, Inhalant, Food, Contact
What is flea or insect bite allergy and how is it treated?
Spiders, ticks, and insects, including fleas, blackflies, deerflies, horseflies, mosquitoes, ants, bees, hornets, and wasps, can cause an allergic reaction in sensitive dogs. Flea saliva is by far the most common insect allergen in dogs. Most dogs experience minor local irritation from flea bites. However, a dog with a flea allergy will react to a single bite with severe local itching. The pet will bite and scratch itself and may remove large amounts of hair, especially in the tail-base region. A secondary bacterial infection may develop in the areas of broken skin.
If your pet is flea allergic, strict flea control is essential. This is difficult considering the life cycle of fleas, but modern monthly flea preventives and home treatment options allow you to provide a flea-free environment for your dog. Ask us about tips on protecting your dog and other pets from fleas. When strict flea control is not possible, or in cases of severe itching, we may prescribe antihistamines or corticosteroids (steroids) to block the acute allergic reaction and give immediate relief. If a secondary bacterial infection is present, an appropriate antibiotic will be prescribed.
What is inhalant allergy (atopy) and how is it treated?
The term inhalant allergy in the dog is often used as a synonym for atopy. The main inhalant allergens are tree pollens (cedar, ash, oak, etc.), grass pollens, weed pollens (ragweed), molds, mildew, and house dust mites. Many of these allergies occur seasonally, such as ragweed, cedar, and grass pollens. However, others such as molds, mildew, and house dust mites occur year-round.
When humans inhale these allergens, the resulting allergy primarily manifests with upper respiratory signs: runny eyes, runny nose, and sneezing (hay fever). Although sometimes the symptoms of allergies include respiratory signs, in most dogs, atopy manifests with itchy skin (pruritus). Due to these clinical signs, the condition is also called inhalant allergic dermatitis. The dog may rub its face, lick its feet and scratch the axillae (underarms).
Most dogs that have inhalant allergy start showing signs between one and three years of age. Affected dogs will often react to several allergens and often also experience flea or food allergies. If the offending allergens can be identified by intradermal skin tests (skin testing), the dog should be protected from exposure to them as much as possible. Because most of these allergens are environmental, this is difficult, and recurrent bouts are likely. Symptoms of atopy can be controlled, but a permanent cure is not usually possible.
Treatment depends largely on the length of the specific allergy season. It may involve one or more of the following three therapies:
Anti-inflammatory therapy. Treatment with anti-inflammatory drugs such as corticosteroids, or with antihistamines, will quickly block the allergic reaction in most cases. Fatty acid supplementation of the diet can improve the response to steroids and antihistamines in some cases. Recently-approved drugs such as oral cyclosporine are also very beneficial in treating atopy and have fewer long-term side effects than corticosteroids.
Shampoo therapy. Frequent bathing with a hypoallergenic shampoo can be soothing to itchy, inflamed skin. Bathing also rinses out allergens in and on the coat that can be absorbed through the skin. Some therapeutic shampoos also contain anti-inflammatory ingredients that may further benefit your pet.
Desensitization therapy. If the specific offending antigens are identified by allergy testing, an allergy injection serum or allergy shots can be given to the patient. With this treatment, very small amounts of the antigen are injected weekly. This repeated dosing has the objective of reprogramming or desensitizing the immune system. Success rates vary with this treatment. Approximately 50% of treated dogs will see significant improvement in their clinical signs, while approximately 25% more will see a decrease in the amount or frequency or corticosteroid usage.
What is food allergy and how is it treated?
Food allergy is typically in response to the protein component of the food; dairy products, beef, wheat gluten, chicken, chicken eggs, lamb, and soy are commonly associated with food allergies in dogs. Food allergy can develop at almost any age. Food allergy may produce any of the clinical signs previously discussed, including itching, digestive disorders, and respiratory distress. A dog may have multiple types of allergy, such as both food allergy and atopy making the exact diagnosis of a dog’s itching quite challenging.
Treatment of food allergy requires identifying the offending component(s) of the diet and eliminating them. The most accurate way of testing for food allergies is with an elimination diet trial using a hypoallergenic diet. Because it takes at least eight weeks for all other food products to be eliminated from the body, the dog must eat the special diet exclusively for eight to twelve weeks.
It must be emphasized that if the diet is not fed exclusively, a food trial will not be a valid test. All table food, treats, and flavored vitamins must be discontinued during the testing period. Even certain types of chewable tablets or medications such as heartworm preventive can interfere with test results. We will discuss the specific diet and restrictions recommended for your dog and will provide instructions based on the results of the food trial.
At Jewell Animal Hospital, we have found that most pet allergies are not food allergies, but they can develop in some pets. We will perform a thorough examination, history review, and any appropriate tests to determine if your pet truly has food allergy, another allergy, or some other underlying condition. Based on our findings, we will develop an optimal treatment plan to relieve your pet’s discomfort.
What is contact allergy?
Contact allergy is the least common type of allergy in dogs. It results from direct contact to allergens, such as pyrethrins found in flea collars, pesticides used on the lawn, grasses, materials such as wool or synthetics used in carpets or bedding, etc. Contact allergies can develop to practically anything and at any age.
If the dog is allergic to any of these substances, there will be skin irritation and itching at the points of contact, usually the feet and stomach. Removal of the allergen (once it can be identified) often solves the problem.
Caution: The symptoms of allergies can be confused with other disorders or occur concurrently with them. Therefore, please contact us so we can diagnose your pet’s issues. We will perform a full diagnostic evaluation to rule out other causes of itching and skin problems. If an allergy is diagnosed, your whole family must follow our recommendations closely to relieve your pet's discomfort.
This information is based on material written by: Catherine Barnette, DVM; Ernest Ward, DVM © Copyright 2018 LifeLearn Inc. Used and/or modified with permission under license.
Why is my pet losing hair?
Hair loss is very common for pets that are constantly itching. In this case, the reason for the itching needs to be identified. Likely causes are allergies, bacterial and fungal skin infections, or parasites.
If your pet is losing hair, but not itching, then possible causes are hypothyroidism, Cushing’s disease, alopecia, genetics, or drug or vaccine reactions.
We will need to perform a complete physical exam and medical history to try and determine the underlying cause of the hair loss. From there we can work with you to develop a treatment plan.
Cytology - Fine Needle Aspiration (FNA)
What is cytology?
Cytology is the microscopic examination of cells that have been collected from body tissues. By examining the appearance of these cells and looking for inflammation or infection, it is often possible to diagnose specific diseases or determine the nature of a pet's illness.
When is cytology by Fine Needle Aspiration performed?
Fine needle aspiration (FNA), also called fine needle biopsy, is typically used to sample 'lumps and bumps' found on the body. However, it is also used to evaluate:
--Internal organs such as the liver, lung, lymph node, or kidney.
--Body fluids such as urine or joint fluid.
--Abnormal accumulations of fluid found in the chest, abdomen, or around the heart.
How are cells collected with Fine Needle Aspiration?
The FNA technique is very simple: a sterile fine gauge needle is attached to an empty syringe. The needle is introduced into the tissue and the plunger of the syringe is pulled back while the needle is held in the tissue. This creates suction, which aspirates or pulls cells or fluid from the site into the syringe.
Cytology specimens are sometimes collected during an ultrasound examination. These samples are called "ultrasound guided" fine needle aspirates since the ultrasound image is used to locate the site to be sampled and helps the veterinarian position the needle correctly before aspirating the sample.
What happens to the collected cells?
The collected tissue or fluid sample is placed on a glass slide and dried by waving the slide in the air or holding it in front of a fan or hair dryer. The resulting “air-dried smear” is then stained with special dyes and examined under a microscope.
After this examination, we will explain the results and discuss any necessary next steps with you.
Is any special preparation required before collecting the sample?
For routine sampling of lumps and bumps on the body surface, there is usually no special preparation required, although a simple disinfectant like alcohol may be applied to the skin before sample collection. However, when samples are collected from internal organs or need to be tested for bacteria, sterile surgical technique must be used during collection and handling of the sample. This involves shaving the fur, cleaning and disinfecting the skin, and wearing surgical gloves, etc., just as would be done in preparation for surgery.
Is cytology by FNA always diagnostic?
Cytology by FNA is not always diagnostic, but in those cases where the results do not provide a definitive diagnosis, they usually contribute valuable information that ultimately leads to a final diagnosis.
What is the next diagnostic step after cytology?
The next diagnostic step after cytology is histology. Histology is the microscopic examination of solid tissue collected surgically from the pet. Histology looks at how cells and tissues are organized and determines if there is any disruption in the normal pattern.
In most cases, histology will provide a definitive diagnosis, and is generally considered the diagnostic "gold standard." Histology may be needed to determine if a tumor is benign or malignant and is routinely recommended to confirm the cytological findings. If your pet has a growth surgically removed, we typically recommend that the tissue be sent away for histological examination.
This information is based on material written by: Kristiina Ruotsalo, DVM, DVSc, Dip ACVP & Margo S. Tant BSc, DVM, DVSc © Copyright 2011 Lifelearn Inc. Used and/or modified with permission under license.
Skin Masses or Lumps
A lump or mass on your pet’s body can be caused by several different conditions, some more worrisome than others. The less worrisome lumps are things like cysts, warts, infected hair follicles, or blood blisters. However, even these non-cancerous masses can be bothersome for your pet, and therefore removal may be recommended.
Cancerous lumps are obviously much more troubling. These can be benign or malignant. Impression smears or biopsy are used to collect cells for evaluation. Every case is unique and needs to be evaluated to determine the best treatment. Treatment often involves surgical removal. Chemotherapy, radiation, or other experimental treatments may be recommended for cancerous lumps.
It’s a good idea to regularly check your pet’s body for lumps and bumps and reach out to us right away should you find something unusual.
Lumps, Bumps, Cysts & Growths - PetMD, retrieved from https://www.petmd.com/dog/general-health/evr_dg_lumps_and_bumps
Ear Infections (Otitis Externa)
How common are ear infections?
Infection of the external ear canal (outer ear infection) is called otitis externa and is one of the most common types of infections seen in dogs. Some breeds, particularly those with large, floppy or hairy ears like Cocker Spaniels, Miniature Poodles, or Old English Sheepdogs, appear to be more prone to ear infections, but ear infections may occur in any breed.
What are the symptoms of an ear infection?
Ear infections are painful. Many pets will shake their head and scratch their ears trying to relieve the discomfort. The ears often become red and inflamed and develop an offensive odor. A black or yellowish discharge commonly occurs. In chronic cases, the ears may appear crusty or thickened, and the ear canals often become narrowed due to the chronic inflammation.
Don't these symptoms usually indicate ear mites?
Ear mites can cause several of these symptoms, including a black discharge, scratching, and head shaking. However, ear mite infections are more common in puppies and kittens. Adult dogs may occasionally contract ear mites from puppies or cats that are infected. Ear mites create an environment within the ear canal that often leads to a secondary bacterial or yeast (fungal) infection.
Since these symptoms are similar and usually mean an infection, why can't I just get some ear medication?
There are several kinds of bacteria and at least one type of fungus that commonly cause ear infections. Without knowing the specific kind of infection present, it is not possible to know which medication to use. In some cases, the problem is a foreign body, a polyp, or a tumor.
Treatment with medication alone will not resolve these problems. Also, administration of certain medications can result in loss of hearing if the eardrum is ruptured. It is important that your pet be examined to ensure that the eardrum is intact.
How do you know which drug to use?
First, the ear canal is examined with an otoscope, an instrument that provides magnification and light. This examination allows us to determine whether the eardrum is intact and if there is any foreign material in the canal. When a pet is in extreme pain and refuses to allow the examination, it may be necessary to sedate or anesthetize the pet for a thorough examination.
The next step is to examine a sample of the material from the ear canal under a microscope to determine the type of organism causing the infection. Microscopic examination is important in helping us choose the right medication to treat the inflamed ear canal. Culture and susceptibility tests are often used in severe or chronic ear infections to ensure your pet is receiving the right medication.
How are ear infections treated?
The results of the otoscopic and microscopic examination usually determine the diagnosis and course of treatment. If there is a foreign body, wax plug, or parasite lodged in the ear canal, it will be removed. Some pets must be sedated for this, or to allow a thorough ear flushing and cleaning. Some pets will have more than one type of infection present (e.g., a bacterium and a fungus, or two kinds of bacteria). This situation usually requires the use of multiple medications or a broad-spectrum medication.
An important part of the evaluation of the patient is the identification of underlying disease. Many pets with chronic or recurrent ear infections have allergies or other conditions. If underlying disease is suspected, it must be diagnosed and treated, or the pet will continue to experience chronic ear problems.
What is the prognosis?
Nearly all ear infections that are properly diagnosed and treated can be successfully managed. However, if an underlying cause remains unidentified and untreated, the outcome will be less favorable. Several recheck examinations may be needed before the outcome is successful.
How important is it to treat an ear infection?
Pets with ear infections are uncomfortable. Their ears are a source of constant pain, and they frequently scratch them and shake their head. In dogs, this can cause a condition called an 'aural hematoma,' in which blood vessels in the ear flap break, causing a painful swelling that requires surgical treatment. Deep ear infections can damage or rupture the eardrum, causing an internal ear infection and even permanent hearing loss.
This information is based on material written by: Ernest Ward, DVM; Updated by Amy Panning, DVM © Copyright 2017 LifeLearn Inc. Used and/or modified with permission under license.
From the Doctor...
Our goal at Jewell Animal Hospital is to provide a warm, caring, and flexible environment for pets and their owners. With an emphasis on great customer service and the latest medical, surgical, and pain management techniques, we want clients to feel that their companion animals are getting the best possible care available anywhere in Chicago!