Just like humans, pets can suffer from allergies to things such as foods, mites and pollens, with the allergens entering the body through the skin or when your pet eats or breathes them in.
Pet allergies are one of the more common problems that we see in practice with symptoms ranging from scratching and itching to hotspots, hair loss, infections and open sores. While allergies are more common in dogs, we do see quite a few cats with the problem as well.
Allergies can manifest themselves in many ways in our pets and generally cause them to scratch, rub, lick or nibble at the affected area. Some of the more common signs that a pet may have an allergy are;
- Licking or nibbling at certain areas
- Bottom scooting
- Reddened, inflamed and sore skin, ears flaps, ear canals and gums
- Rashes and lesions or hotspots
- Wet Eczema
- Crusts on the skin or in the ears
- Excess of ear wax
- Discharge from the eyes and/or ears
- Red and sore eyes and conjunctiva
- Eye watering and/or gunky discharge
- General itchiness – Scratching or rubbing at or near affected area
- Hair loss or thinning patches
- Dull, dry or brittle coat
- Yeasty or odd smell from the coat, ears or skin
- Diarrhoea (food allergy)
- Vomiting (food allergy)
- Lack of appetite
- Weight loss
- Bloating (food allergy)
- Respiratory problems (usually cats)
- Repeated Anal Gland problems or infections
- Behavioural changes – often due to being uncomfortable and itchy
A pet with allergies is often in discomfort and pain, so if you see any of these symptoms you should make an appointment with your veterinary practice.
How Pets Develop Allergies
Allergies are an overreaction of the body’s immune system which normally protects the body from viruses and bacteria by producing antibodies to fight them. During an allergic reaction, the immune system starts fighting the invading substances that are usually harmless, such as dust mites or pollen, because it has mistaken them for substances/allergens that are trying to attack the body. The first time the body encounters an allergen, the cells create an antibody specific to that allergen which attaches to the surface of the cells. The next time the body is exposed to this allergen, the cells activate their defences and release histamines, prostaglandins and leukotrienes, which are what trigger the symptoms associated with allergies.
Allergies often start to develop when the pet is between one to three years of age, but sometimes they develop when the pet is older. For the majority of cases the pet will have been exposed to the allergen for some time before an actual allergy is developed (with the exception of something like an insect bite, which may develop after only a few bites), the pet’s immune system then starts to react to the allergy. It is also possible for a pet to have allergies to many different things, so over the years the symptoms may get worse. Although any breed, age or sex of dog or cat can develop an allergy, some allergies may also be passed on through generations making some breeds more likely to have an allergy for example West Highland Terriers, Golden Retrievers and Bulldogs.
Types of Allergies
Allergies, Atopy or Atopic Dermatitis are the broad terms for an allergic reaction to something in the environment. Our pets can be allergic to a variety of things in the environment such as Pollen from trees, weeds, flowers and grasses or Moulds and Fungi (both indoors and outdoors), food, parasites, yeasts, bacteria and contact with substances or materials.
Weed, Tree and Mould Allergies
Many pets develop allergies to the pollen of certain trees, weeds and grasses as well as spores from moulds and fungi. These can be very difficult (if not impossible) to avoid contact with and cause allergy flare ups at certain times of the year.
It can take a great deal of detective work to work out exactly which ingredient in a pet’s diet is the cause of the allergy, for example it could be the meat or it could be a cereal ingredient, or even one of the additives used to preserve the food. Symptoms of food allergies can include tummy upsets as well as general itchiness, skin and ear problems and also behaviour problems. They should not be confused with food intolerances, which only affect the gastrointestinal system (vomiting, diarrhoea, weight loss) and not the skin. True food allergies are really quite rare in dogs and cats.
Flea and Mite Allergies
These are very common and can be very uncomfortable for pets.
- Fleas: In some animals one bite from a flea can leave them itchy and sore for 2-3 weeks and they may get a secondary infection because of all the scratching, nibbling and licking they are doing. For animals allergic to flea saliva (Flea Allergic Dermatitis) it is vitally important that flea treatments are kept up to date both on the pet and in the home.
- House Dust Mites: These tiny mites live in the home in carpets, bedding, mattresses, upholstery and even cloth toys. They feed on human skin scales, bacteria and fungi in the environment. They are a common cause of allergies in people as well as pets. Frequent vacuuming and washing of the pets bedding and near environment can help keep these allergies under control, but pets with Dust Mite allergies often need immunotherapy vaccines to help them.
- Storage Mites: These microscopic mites are attracted to dry foods, grains and cereals. The storage mite’s body and its faeces can trigger an allergic reaction in dogs and cats. These can be difficult to avoid and it is sometimes necessary to change an allergic pet to a wet food instead of a dry one. Pets with Storage Mite allergies often need immunotherapy vaccines to help them.
These are usually caused by contact with certain carpet materials, cleaners, plastics or rubber. They often show as red itchy bumps or blisters on areas of skin that are not covered with a good layer of hair such as the tummy, feet, or muzzle.
Pets with allergies will often have what we term secondary skin problems, and these are usually related to a bacterial or yeast infection. The allergy causes the initial skin irritation and the cycle of scratching and licking at the skin then leads to a secondary infection. Treatment given for these secondary infections can often seem initially to ‘cure’ the problem, but the underlying allergic cause remains and so the problem will reoccur. This is why we strongly recommend a full investigation if a pet has recurring problems so that we can fully understand the problem and limit its return.
Allergies are diagnosed using a variety of methods, depending on the suspected cause of the allergy. Your pet will initially have a thorough examination which may include blood tests in order to rule out any illnesses or diseases which can affect the skin and coat (i.e. Cushing’s or Addison’s Disease). An allergy workup will include some, or all of the following;
- Dermatology Consultation – The vet or qualified veterinary nurse will establish your pet’s daily routine and exactly what your pet eats, where you take them for walks, and his or her sleeping and resting areas in the home etc. to see if we can identify possible allergic causes.
- Cytology – This is one of the most beneficial tests for pet’s with skin problems. Examining skin cells under the microscope can help identify whether bacteria and yeasts are present in abnormal numbers.
- Skin scrapes and hair plucks – These can be examined under a microscope, either in practice or at an external laboratory and can show us whether the pet has a fungal infection (i.e. ringworm) or a mite infestation (i.e. demodex). Ruling these causes out can go a long way to confirming an allergy.
- Allergy Blood tests – Blood serum is to an external laboratory where it can be examined and exposed to various allergens such as pollens, mites and fleas. A report is then sent back to the vet telling them which of these the pet is allergic too. (Sadly we cannot use this for food allergies)
- Skin Biopsy – This is a slightly more invasive test, but can usually be performed using a local anaesthetic (if the patient will tolerate it).
- Food Exclusion Trials – The only way that a food allergy or intolerance can be properly diagnosed is with a strict food elimination trial for 3 – 10 weeks (depending on the pet’s symptoms) and then the re introduction of the original diet. The choice of which diet to use for elimination trial is very important and t has to contain ingredients that the pet has never eaten before. It is often not as simple as changing from a chicken based pet food to a fish based one.
Treatment of Allergies
Once an allergy has been diagnosed and the cause has been found, treatment can be recommended; we cannot cure an allergy, but we can help make the body less responsive to an allergen and sometimes it may even be possible to prevent the pet from coming into contact with the allergen at all. Allergy treatment may include.
Removal and/or Avoidance Techniques
Some allergens can be removed completely if we know the allergen in question; cleaning products can be changed and allergic materials can be removed or avoided. In some cases such as flea, mite or mould allergies we may not be able to completely remove the source but there are several avoidance techniques that can be employed such as
- Keep pets out of room for several hours during and after vacuuming
- Use a plastic cover over pet’s bed
- Wash bedding in very hot water
- Avoid letting pets sleep on furniture
- Avoid or regularly wash cloth toys
- Keep pets in uncarpeted rooms
- Run an air conditioner during hot weather
- Keep pets indoors when the lawn is mowed
- Avoid dusty low quality pet foods or switch to a wet food
- Use of airtight containers for food that are cleaned thoroughly between batches
- Use of specific food bowls that are cleaned thoroughly between uses
- Use dehumidifiers
- Avoid large numbers of houseplants
- Rinse the pet off after walks in high grass and weeds during times of high pollen
- Ensure that parasite control both on the pet and in the home is kept up to date
These usually offer immediate and short term relief for the pet and may be in the form of creams, ointments, drops, lotions or shampoos that may be used to treat specific areas such as skin lesions, ears or eyes.
These are usually in the form of tablets or injections
Corticosteroids – These are very effective at relieving severe itching and inflammation. They are usually given daily for a set period and then the dose will reduced. For longer term treatment the pet will have the dose reduce to the minimum therapeutic level. Some pets experience side effects when on steroids (as with any drugs) such as increased thirst, increased urination, increased appetite and diarrhoea. Very long term steroid medication is usually avoided because of the potential of more serious side effects.
Cyclosporine – This medication specifically targets the immune cells involved in the allergic response and blocks the release of inflammatory molecules such as histamines which cause the allergic symptoms.
Antihistamines – These are widely used in both humans and animals to provide allergy relief. They have been shown to be effective in controlling allergies in up to 30% of dogs and 70% of cats and are especially effective when used with omega 3 fatty acids and avoidance therapies. However, just like in people, every animal will respond differently to each of the different antihistamines. So the vet may have to try a few types before an effective one is found. Antihistamines should only ever be given to pets under veterinary guidance as some have severe side effects including
- Decreased appetite.
Oclacitinib Maleate – This drug for dogs suppresses the itch and inflammation response, meaning that the dog will feel much more comfortable and won’t keep scratching, which can often make the problem much worse.
Immunotherapy is the treatment of disease by inducing, enhancing, or suppressing an immune response using the causal agent. An Immunotherapy Vaccine is given to the pet in the form of an injection and will stimulate the body’s immune system (in a similar way to vaccinations against disease in people and animals). Each Immunotherapy vaccine is designed specifically for an individual pet and contains small doses of the allergens that the pet is allergic to. The dose of the vaccine increases in the amounts and concentrations of the allergen each time it is given, which will eventually decrease the body’s sensitivity to the allergen, meaning that the pet will develop fewer and less severe symptoms when they are exposed to the allergen in the future.
Do not confuse immunotherapy with homeopathy – immunotherapy vaccines are precisely made up by the veterinary laboratory for each individual pet and contain exactly the substance(s) that causes the allergy in your pet at the correct dosages. They work by stimulating a response in the animal’s immune system.
Acupuncture is a therapeutic process in which a veterinary practitioner inserts fine needles into certain points on the pet’s body to help control pain and ailments. Veterinary acupuncture has been shown to help ease the symptoms of inflammatory conditions in some dogs and cats. This treatment should only be carried out by a veterinary surgeon – At Castle Vets this is Christel Van Veen and you can find out more by visiting our website.
Omega 3 and Omega 6 Fatty Acids
Essential polyunsaturated fatty acids have been proven to have a therapeutic benefit in the treatment of canine atopic dermatitis and other inflammatory conditions. In some animals they can help reduce the itchiness and inflammation in the skin because of their natural anti-inflammatory and anti-oxidative agents. You should always seek veterinary advice regarding dosages before you start to supplement your pet’s diet though.
Occasionally a pet suffering with allergies may need surgical treatment to help alleviate the symptoms. This is usually ear canal surgery carried out on dogs with repeatedly swollen and infected ears due to their allergies.
The central idea behind homeopathic remedies is “like cures like” – a substance that causes certain symptoms can also help to remove those symptoms. A second central principle is based around a process of dilution and shaking, called succession – Homeopathic practitioners believe that the more a substance is diluted in this way, the greater its power to treat symptoms. Many homeopathic remedies consist of substances that have been diluted many times in water until there is none or almost none of the original substance left. Another problem with homeopathic remedies is that they are given orally and because of this most of the ingredients never make it past the acid in the stomach and what little does get through is too diluted to have any effect.
However, if you feel that homeopathic remedies can be used to help your pet then no one will mind you using them – but do let your vet know which remedies you are using.
Dermatology Clinics At Castle Vets
John Redbond RVN has a special interest in allergies and skin problems in pets and runs the Pet Dermatology Clinic at Castle Vets. John is available to discuss and investigate allergies in your pets and runs his clinic on a Tuesday morning.
During Pet Allergy Week, 6th-12th June, John will be offering FREE dermatology consultations, including cytology testing where appropriate (normally charged at £35-£55), for anyone who is concerned that their pet may be suffering from an allergy.
If you would like advice on allergies or to make an appointment, please contact Castle Vets on 0118 9574488