Changing of dry food brand and type resolves the problem of skin allergies in this 2004 case

Dr Sing Kong Yuen, BVMS (Glasgow), MRCVS
Case written: May 5, 2004
Case updated: Sep 6, 2008

"The dog does bite," Mrs Tan said as the 23-kg white and black cross-bred crashed into her. She tripped her and tumbled onto the concrete floor outside the surgery.  Was she injured? 

I had suggested that her dog be examined outside the surgery as it would not feel so threatened.  Mrs Tan was not able to control it.  It was best that the dog not be handled by me or the veterinary staff as that would make him more fearful.

Mrs Tan struggled to get up and to hold on to the dog's  leash to prevent him from escaping, as a horse groomer would hold onto a hyper-excited racehorse from bolting.

This dog could smell a vet 10 km away and was not going inside to be injected. His luscious thick white collar hairs stood on end. No threatening growl to warn the vet.  I could see small bumps on the whole back. This could be urticarial lumps due to allergies or goose pimples from a scared dog.

What should be done in this situation? "Can your son restrain this dog?" I asked Mrs Tan.  Her sun-burnt teenaged son had glued his mobile phone to his left ear. A young man in a hurry. He wanted to go back as soon as possible and here, I was waiting for the dog to settle down so that I could see his bright red rashes under his belly and arm pits.  This took at least ten minutes.

"My son will not be able to restrain the dog," Mrs Tan said. "Don't worry about his grouchiness. He's going back to the army camp and wanted to hurry back to see his girl friend."   As an ex-National Service full-time person, I could understand the precious last two hours of a Sunday before being confined to another week in the camp.

"It is nice of him to accompany his mother to the vet." I complimented Mrs Tan. "I should hurry up so that he can romance his sweet heart before the army forced him to stay in the barracks for the next six days."

Yet, this dog was not docile and rushing him meant more haste, less speed.

Mrs Tan had said that an injection by another vet had been effective in stopping the itchiness.  However, the practice was not opened on this Sunday. Besides, her favourite vet worked only twice a week.  "He had suffered a stroke," she said. 

"The vet had  a mild stroke and should have recovered," I said, in case she wanted to see him. 

"I had to wait a very long time before I could consult him. The second visit, I was referred to his colleague who prescribed the medications.  One of them is for fungal infections. This fungal infection has recurred and the tablets would resolve his itchiness."

She met me yesterday at a dinner gathering of old friends of my wife on May Day.  I told her that the anti-fungal tablets might not work if the dog had no fungal infection. Her complaint was that the dog was getting itchier every day for the past week.  Therefore, it was best to re-examine the dog.

The dog refused to enter the surgery.  Mrs Tan and her son would not be able to restrain him. So, was this a case that could not be closed?  Would she have to go home now?

"Do you have a cage so that my dog could enter it and be given an injection?  The other vet had this cage."  Mrs Tan asked. 

"An injection is needed to reduce the itchiness," I had told  Mrs Tan at the party yesterday.   All dog owners judge a vet by the results. The vet with the stroke had reduced the dog's itchiness and therefore was her favourite first-choice vet.

Performance counts for all service providers. Customers seldom give you a second chance. "It is not that the vet from the first practice you went to was incompetent," I said to Mrs Tan. "Sometimes, it is the dosage, compliance with taking the medication and the need for re-examination within 10 days of treatment.  Many owners seldom go to the vet for a review of the progress of the skin disease."

Mrs Tan retorted, "I had seen that vet three times but my dog was still itchy. That was why I switched to another practice.  The vet (with the stroke) is very good."

Now, the dog was already ready to fight.  Saliva spitted from his mouth. It would fight to the end to avoid entering the cage if I had one.  So, what should I do?  The dog was family and the genteel and fair lady owner was not able to control it well. I was worried that she might get bitten.

Yet, the dog needed an anti-itch injection.  Muzzling him was out of question. He was strong and massive. His rounded body and broad chest with weight gain, after being neutered by Mrs Tan's favourite 5 years ago and subsequent good appetite made him a formidable animal.

How to restrain him without Mrs Tan feeling that he was roughly handled?  This dog was family. A "son" with strong jaws and powerful legs.

"I am not in a hurry," Mrs Tan said. Her son was checking me to see how long it would take.  Mrs Tan said, "Ignore his grouchiness. His girl friend is in my house!"  Mrs Tan is the type who could read minds, the type of people with that extra sensory perception. She assumed  correctly that I was worried that her son was had to meet his girl friend somewhere.

I squatted down to view the dog. He had settled down. I could see the deep redness of the belly and the arm pits as the dog eyed me suspiciously.  There was no physical contact. "I will go inside the the surgery to get the injection." I told Mrs Tan.

The dog refused to budge as I asked Mrs Tan to bring the dog to an iron pole on a 3-meter wide pavement outside the surgery.  This pole was constructed by the authorities to prevent cyclist from using the pavement. I  could wind the leash round the pole till the the dog's head was pulled  closer to the pole and he would not be able to turn and bite while I injected his back muscles.

The theory was sound. The dog just would not be tethered to the pole. "Just gently push him closer," I asked Mrs Tan.  Ms Ho, an 18-year-old pre-university student who wanted to be a vet was seeing practice. 

This was a chance for her to learn animal husbandry and to experience the risks of being a canine veterinarian.   Yet, would the dog bite her? Would I be sued if the dog bit her? Should I just let her be an observer on the side-line?  Yet, how could a person learn just by merely watching and not being hands-on?

Ms Ho's heart must be beating three times faster. I could see her eye pupils dilated as she was not brought up with dogs. Now, she was handling a canine sumo-wrestler.  

Mrs Tan observed her, "My dear, you can't be a vet if you are frightened of dogs." 

Mrs Tan asked me, "Have you been bitten by dogs?"

I nodded my head, trying to focus on this tiger whose tongue was turning purplish as I tightened the leash. "Ms Ho would learn how to handle animals during the veterinary studies. In fact, I had no experience of dogs before I went to Glasgow University to study veterinary medicine," I said.

Many Singaporeans have no chance to keep dogs as pets if their parents disapprove or harsh family economic conditions prohibit.  Ms Ho lived in a 2-bedroom Housing & Development Board apartment, the smallest of all HDB apartments.

Extracts from the Asiahomes.com Book:
How Your Puppy Can Live Longer  
Dr Sing Kong Yuen, BVMS (Glasgow), MRCVS.

UPDATE IN SEP 6, 2008
Mrs Tan's dog did not have any skin allergies. Ms Tan had given him another brand and type of dry dog food. So, I have not seen Ms Tan for the past 2-3 years. In this case, the allergy would be due to the eating of certain ingredients in the dry dog food given earlier. Once the allergen is removed, the dog no longer itches. As to which ingredient in the dry dog food, it is very hard to say.

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What is an allergen?

Any substance, such as pollen, mold, chemical or animal dander, that can trigger an allergic response.

How do you test for allergies?

To determine which specific substances are triggering your allergies, your vet will test your dog's skin, or sometimes its blood, using tiny amounts of commonly troublesome allergens.

 There are several types of tests:

• Scratch or puncture tests in which a tiny amount of allergen is scratched across or lightly pricked into the skin. If your dog has an allergy, the specific substances that your dog is allergic to will cause an allergic reaction in its body that culminates in redness and swelling.

  Swelling will occur only in the spot where an allergen to which your dog is allergic is scratched onto its skin.  Its skin will swell and itch.
   

• Intradermal test, a modified, slightly more sensitive version of the scratch or puncture test that involves injecting a tiny amount of allergen under the skin, usually on the  abdominal skin. Your vet may do this test when your dog's reaction to the scratch test cannot be clearly determined.
   
• The RAST, or radioallergosorben, test involves drawing blood. It costs more, and the results are not available as rapidly as skin tests. RAST tests are generally used only in cases in which skin tests can not be performed, such as on patients taking certain medications or those with skin conditions that may interfere with skin testing.

What's the best way to avoid allergies?

The best way to cope with spring allergies is to avoid contact with the allergens. 

What medications are used to treat allergies?

Antihistamines are used to prevent or relieve the symptoms of allergic rhinitis and other allergies. They work by preventing the production of histamine, a substance produced by the body during an allergic reaction.

Decongestants are used to treat nasal congestion and other symptoms associated with colds and allergies. They work by narrowing blood vessels, leading to the clearing of nasal congestion. Steroid nasal sprays reduce nasal inflammation and the accompanying congestion, sneezing and runny nose. 

Steroids are given by injection or orally to reduce inflammation.

What is immunotherapy?

Treatment may include immunotherapy, better known as allergy shots, which work by desensitizing the immune system to a specific allergen through periodic injections of the offending substance in gradually increasing amounts. Injections, which are usually given monthly for up to five years, typically begin to take effect within three to six months. Immunotherapy is ultimately successful in up to 90 percent of patients with seasonal allergic rhinitis and up to 80 percent with perennial allergic rhinitis.

What's the link between allergies and asthma?

So-called allergic asthma accounts for about 60 percent of all asthma cases. It is triggered, not surprisingly, by an allergen — be it pollen, dust, mold or animal dander. When an allergic person is exposed to an allergen, a series of reactions is set off.

First, antibodies in the immune system whose purpose is to capture unwanted invaders are produced. These antibodies, dubbed IgE, journey through the bloodstream and lock onto the surface of so-called mast cells, plentiful in the nose, eyes, lungs and gastrointestinal tract. Then they lie silently in wait until the allergen strikes again. The IgE antibodies, now poised, jump on and gobble up the allergens, triggering the release of inflammatory chemicals such as histamine and prostaglandin.

The airways become inflamed, boggy and red — very much like the skin of an eczema patient. This, in turn, causes the airways to narrow, or bronchospasm. The victim begins to wheeze, cough, even lose his breath.

What is the major risk factor for contact dermatitis?

A family history of allergies is the single most important factor that predisposes a dog to develop allergic disease.

Can weather influence contact dermatitis symptoms?

No, unless the cause is air-borne. Allergy symptoms are often minimal on days that are rainy, cloudy or windless, because pollen does not move about during these conditions. Hot, dry and windy weather signals greater pollen and mold distribution and thus, increased allergy symptoms.

What about locale?

If your dog is allergic to plants in your area, you may believe that moving to another area of the country with different plants will help to lessen your dog's symptoms. However, many pollens from the grasses, molds and related plants can also trigger the same symptoms.

As a result, many who move to a new region to escape their allergies find that their dogs acquire allergies to new air-borne allergens prevalent in their area within one to two years. Therefore, moving to another part of the country to escape allergies is not recommended.  

Conclusion:
Skin diseases are sometimes very difficult to treat and costs the owner a lot of money. Avoidance of allergens is impossible if the nature of the allergens is unknown. Many Singapore dog owners are fed up with the veterinarian as cure is not achieved within a week or two.

Generalised and chronic skin diseases are costly to treat and there is a need to do many tests which the owner may not want to pay for. Performing such tests may also not result in finding a permanent cure. Such owners abandon the dog and are not happy.