More Allergies

How can we test my pet for what they are allergic to?

The first point to be made about allergy testing is that testing should only take place after a diagnosis of an airborne allergy is made.  A diagnosis is made by clinical signs and your pet fitting many of the criteria that have previously been discussed.  The reason that a diagnosis should be made first is testing is not 100% accurate and there is the possibility of false positives.  This means that pets without allergies can have positive responses to allergy testing.  The second point to discuss before testing is why we are testing.  The reason we are performing “allergy testing” is to identify what allergens are causing a problem, so we can make a solution with these allergens to perform immunotherapy.   We will talk about immunotherapy shortly.

There are two ways to test for what your pet is allergic to:

      Intradermal skin testing (IDST): For this procedure your pet is sedated and a patch of hair is shaved on his/her side.  Small amounts of concentrated allergen (pollens, molds, grasses, weeds) extract are then injected under the skin and the reaction to the allergies are measured.  Allergens that your pet is allergic to should puff up and become red.  In order to get accurate results on these tests your pet will need to be off of antihistamines for a minimum of 2-4 weeks and off steroids for at least 4-6 weeks.  This testing does typically require referral to a veterinary dermatologist and the usual cost is ~$380.  This is considered the “gold standard” for allergy testing.  The best time of year to test is usually in the early fall (Sept/Oct).

      Serum antibody testing: This is a different way of testing for allergies in pets.  The pros of this test is that it does not require referral, only requires a blood draw, and typically your pet does not need to be off of steroids or antihistamines for testing.  The drawback is that you can have some false negative or positive results (this is true for any testing).  For this test the amount of antibodies (specifically IgE which is associated with allergies) to specific allergens are quantified.  Those allergens with higher antibody levels are deemed the problem allergens.  The cost for testing is ~$200.

It is possible with both tests to get negative results (no reaction to allergens).  For dogs that obviously have an allergy problem there can be a few reasons for negative tests including:

1. Improper withdrawal of steroids/antihistamines

2. Wrong time of year for testing

3. Improper choice of allergens being testing

If your pet has a negative allergy test, then it may be suggested to try the other type of testing (IDST versus serum testing or vice versa).

My pet had allergy testing performed, now what?

Once your pet has been allergy tested and the offending allergens are identified, then we can proceed to immunotherapy.  Immunotherapy involves making a solution that contains small amounts of the different allergens that your pet is allergic to.  This solution is then injected under the skin (or more recently placed under the tongue) every few days.  There is an initial induction phase (6-10 weeks) where the solution is dilute and then over the next few weeks the amount given and the concentration of the solution are increased.  Once we have reached the maintenance phase, your pet will be getting injections every 1-2 weeks.    Many dogs (60-70%) show improvement with immunotherapy.   This does not necessary mean that the itching symptoms will go away completely.  In many cases, pets may need additional therapy (anti-histamines or steroids) during certain times of year, but hopefully the dosage, frequency and length that these medications are needed will be reduced.   The improvement are not immediate either.  Pets typically take 3-5 months to show improvement and in some cases can take upwards of a year.  The cost per year for a typical dog on immunotherapy is ~$620.  This therapy is typically continued life long, but in some instances can be stopped after a few years of therapy.

Allergies

Although it is not the time of year for allergies to hit, it is always a conversation I have with owners (whether it be at work or when I mention I am a veterinarian to something).  I figured it would be a good topic to hit on.

Is my pet allergic?

Most people are familiar with allergies in people and may even have allergies themselves.  They avoid going outside in the spring when the trees are pollinating or don’t go over to a friend’s house because of a pet.  Who wants a runny nose anyway?  Well, dogs and cats can also have allergies, but instead of runny noses or sneezing they tend to get problems with their skin, specifically itchiness.  It can make pets miserable at times, but fortunately we have ways to help relieve some of the symptoms and in some instances can almost cure the condition.

Well, is my pet allergic?

If you think your pet is allergic because they are itching a lot and go to the veterinarian’s office, they will likely ask you a series of questions to get a handle of what is going on.  There are some common criteria that environmental allergies fit into:

Young age of onset: Most pets with airborne allergies start showing symptoms between 6 months and 3 years.  It is typically after the second exposure that symptoms develop.

2.      Seasonality: Airborne allergies typically show up during certain times of year.  Spring is bad for tree pollens, summer for grass, and fall for weeds.  However, if your pet is allergic to dust, dust mites, food mites, or molds, then they may have year round problems.

3.      Response to steroids: Itchiness should respond very well to steroids in allergic pets.

4.      Areas of itchiness: Pets who have localized itchiness in their feet (imagine white dogs with brown feet from saliva staining) typically have an allergy.  Other common areas are the arm pits, feet, around the muzzle and eyes, ears, and butt area.

What are some other possibilities for my pet’s itchiness?

Airborne allergies are not the only cause for itchiness in pets.  There are other things that can cause itchiness as well and should be considered or ruled out before treating your pet.  This may require a few simple tests including cytology of the skin and a skin scraping (both look at material on the skin under the microscope).  Here are a few things that we try to rule out:

1.      

      Other allergy: Pets can have allergies to other things.  The other more common allergies include flea allergies and food allergies.  There are a number of good flea preventatives that can be used along with treating the local environment that can help rule this out.  A “hypoallergenic” diet for 8-10 weeks without any other food sources can rule out a food allergy.  Of course it is not that simple as pets can have multiple allergies as well.

2.      Simple infection: Pets can get infections with yeast or bacteria that can mimic allergic symptoms.  Treating for the infection with resolution of the itchiness and no recurrence is a good indication that the problem was an infection.

3.      Scabies: These are mites that live in the outer layer of the skin.  If these are causing a problem, then all pets in the house are typically itchy, you may be itchy, and typically the ears and elbows are more affected.  Treating with a trial of Revolution (topical spot-on product) for three times two weeks apart can rule this out as skin scrapings don’t always uncover these mites

OK, we are pretty sure my pet is allergic to something in the air, now what?

Once we have come to the diagnosis of an airborne allergy there are a few ways of tackling the problem.  The main ways of helping your pets are 1.) Symptomatic therapies 2.) Avoiding the offending allergen 3.) Allergy testing with immunotherapy injections.

What are the options for symptomatic therapies?

There are a number of drugs available that can help with your pet’s itchiness.  The first thing that we would want to do is treat any concurrent infection.  This is typically done with a combination of oral medications (antibiotic or anti-yeast depending on the problem) and shampoos.  Once we know any infections are under control, then we can try and control the itchiness.

  

      Antihistamines: Although these are not the strongest against fighting the itch, some pets (~15%) respond very well to antihistamines.  I typically recommend trying the medication for 7 days to judge whether there is a response.  Some pets respond better to one antihistamine over another, so you may want to try a few before judging whether or not they help.

a.      Loratidine (Claritin): 0.25 mg/lb once daily, available 10 mg tablet

b.      Cetirizine (Zrytec): 0.25 mg/lb once daily, available 10 mg tablet

c.      Diphenhydramine (Benadryl): 1-2 mg/lb 2-3 times daily, available 25 mg tablet

d.      Chlorpheniramine: 2-12 mg total dose 2-3 times daily, available in 4 mg tablet

e.      Fexafenadine (Allerga): 0.5-1 mg/lb once daily, available in 30 mg (children’s strength)

2.      Steroids: The typical one used is prednisone.  These typically work better than antihistamines to help relieve the itch; however, they do tend do have more side effects.  Minor side effects can include drinking and urinating more, eating more, and occasionally a personality change.  More serious side effects (typically happen when on chronic steroids) are immunosuppression, muscle loss, and making prone to diabetes.

3.      Omega fatty acids: These are typically given in the form of fish oil.  They interfere with the inflammation of the skin that is causing the itchiness.  The usual dose is around 500 mg per 20 lbs, but it is hard to overdose with this medication.  The 500 mg is the active ingredient (DHA + EPA), so make sure you look at the label on the back as it can differ from total mg label on the front.  Usually a double strength product is best.  These can be given whole or broken over the food.  There are also specially formulated foods that have higher doses of omega fatty acids that can be tried (i.e. Hill’s J/D).

4.      Cyclosporin: This medication works very similar to prednisone by suppressing the inflammation in the skin causing the itchiness.  The advantage over steroids is a reduced amount of side effects, particularly the drinking and urinating.  The major downside is cost.  At full strength for a typical 20 lb dog the cost per month is ~$115.  This is typically the starting dose and many times can be reduced after a month or two, but you are still looking at a minimum of ~$65-70 monthly.

5.      Topical therapy: There are many products that can be used topically that help with allergies (shampoos, conditioners, etc).  Recently, a new theory that allergic pets are deficit in certain proteins in the skin has emerged and in response companies have made topical spot-on products to help supplement these deficiencies.

I will talk a little more about allergy testing and immunotherapy in an upcoming post.  I thought this was enough to talk about for now.

Thinking about getting a dog?

With the new year, I see a lot of families with new dogs.  I think it is great to add a pet to the household, but I do find that a lot of people don't prepare themselves for what is involved with a new dog.  Most people decide on getting a dog, but may not think about all the work that goes into a dog.  So, I am going to go over a few questions you might want to ask yourself before going to the humane society, breeder, or store to purchase a pet.

1.) What breed of dog do I want?  It seems a simple question, but it is a good one to ask.  Are you a single person who is looking for a pet to keep you company.  Do you have a family where there are a lot of people available to help with the dog's care.  I wouldn't typically recommend to an owner to get an energetic, young, Labrador if he/she doesn't have the time to walk the dog twice daily for an extended period of time.  We will just run into problems with that dog destroying furniture or "misbehaving" because they have so much energy they need to get out.  Same thing for a person looking to have a pet to play with, or run with, etc; don't look into getting a Shih Tzu as the pet might not be able to keep up with you.  So, ask yourself what breed you might be interested in before getting a pet.

2.) Do I want a puppy versus an adult dog?  There are advantages and disadvantages to both young and old dogs.  Advantages to young dogs are the ability to help shape their personality, high energy level, and of course overall cuteness; however, you typically have to devote more time, lose sleep, and deal with potty training for these pets.  With older dogs you typically get a pet that is already potty trained or may not require as much supervision, but you might not be able to change behavioral issues, might run into medial issues sooner, and the pets life span won't be as long.

3.) Am I going to be able to take care of this pet?  The bill for purchasing the pet isn't the end of spending on this pet.  Once home, you are going to have expenditures for food, toys, veterinary care, damaged furniture  etc.  Remember that veterinarians will recommend being on heartworm and flea preventatives and they will need their shots, etc.  Also, if your pet gets sick, you may have to bring them in for unexpected charges.  It is always a good idea to set aside some money for the care of your pet and also consider pet insurance as this can help if they become really sick.

4.) Am I mature enough for a pet?  Most dogs require constant care and some people may not be ready for a pet.  Although they are cute, pets can be a lot of work and you have to be around to care for them.  If you are used to going away for weekends or overnight, you need to consider where you might keep your pet if they can't come with you.  Some people just don't have time for pets, which is fine, but make sure you realize this before you get your pet.

There are many other questions to ask yourself before looking for a pet.  If you don't think you are ready or have other questions, don't hesitate to call your local veterinarian to ask other questions that you may have about pet ownership.

Urinary Problems

Now that I have talked about behavioral issues and the litter box, let's talk a little more about some medical issues that can lead to problems urinating outside the box.  When trying to determine what the medical issue may be when cats are having problems with the litter box, we first want to determine whether this is a lower urinary tract (bladder) issue or more a problem in the kidneys or elsewhere.

We can usually narrow down the problem just by getting a thorough history.  There will be a few questions asked about how the accidents are occurring:

1. Have you noticed any increased amount of urination or drinking?
2. Is there an increase in frequency of urination?
3. Does there seem to be any discomfort when going to the bathroom?
4. Have you seen any discoloration in the urine or change in smell of the urine?
5. Is it a small amount or large amount of urine when your pet is having accidents?
6. Have you noticed anything else like weight loss, increased or decreased appetite, etc?

When you notice that your pet is drinking more or urinating more and is leaving large puddles outside the box and may or may not be losing weight or having other problems (inappetence or large appetite, etc), then we typically look at either the kidney or other metabolic or endocrine problems.  Your cat is probably having accidents because they are urinating more and might not be able to make it to the box or the box is dirty because they are using it more and then they have an aversion.  Some common medical issues that we see that can lead to this are diabetes mellitus, chronic kidney disease, hyperthyroidism, liver disease, electrolyte imbalances, etc.  We can evaluate for a lot of these problems with some simple testing, which usually includes a complete blood count, serum chemistry profile, urinalysis (+/- urine culture), and thyroid profile.  Occasionally, imaging of the kidney with radiographs or an ultrasound may be recommended.  Once a diagnosis is made, then that particular condition can be treated (insulin for diabetes; change of diet for kidney disease, etc).

If the history includes problems like discomfort when urinating, small, frequent accidents, and blood in the urine, then we are more likely to pursue a problem with the lower urinary system (in particular, the bladder).  When we have histories like this we like to get similar blood work as described above, but the urinalysis, urine culture, and bladder imaging becomes much more useful in diagnosing the underlying problem. The breakdown of common medical problems in the lower urinary tract varies greatly depending on the age of your pet.

When approaching cats younger than ten years old, we typically think that more than half will have a condition called idiopathic cystitis (inflammation of the bladder of unknown cause), a quarter will have bladder stones, and the remainder will have conditions like urinary tract infections, bladder masses, or trauma.  The classic cat with idiopathic cystitis is a young (4-5 year old), male cat who is on an exclusively dry diet.  We usually treat these cats by re-hydrating them (intravenous fluids or subcutaneous fluids), treating their pain, and then giving them time to recover on their own (2-4 days).  In the long term, we try to increase hydration by switching them to an exclusively wet or mostly wet diet along with promoting drinking with a continuous water fountain.  There are also many medications that are used; however, many of these medications don't have definitive evidence that they work.  I find that increasing these cats hydration level works the most to help prevent future problems.  For more more information, visit this site.

When cats are older than ten years, then the distribution of problems shifts and a majority of these patients will have a urinary tract infection, with fewer having bladder stones, and a minority having a bladder mass or other issue.  The treatment will again depend on the underlying problem, but with older pets we also want to look for primary issues that can lead to the infection (chronic kidney disease, diabetes, etc) and treat these underlying conditions.

As you can see, the simple act of urinating outside the box opens up a lot of questions about your cat.  Although it can be difficult to determine the cause, a majority of cases can be solved and it is just a matter of being patient while we are trying to figure out the cause and best treatment for your cat.

Trouble with the Litter Box

It is fairly common for owners to bring their cat in because of problems with their cat urinating outside the litter box.  When this happens, it is the veterinarians job to try and determine whether this is a medical or behavioral problem.  Then, after figuring out what the problem is, trying to come up with a treatment plan.

The first step is getting a good history of when, where, how, etc that these accidents are occurring.  An indication that the problem may be medical would be a history where the cat is straining to urinate, producing frequent, small urine spots, licking a large amount at the back area, drinking more or urinating more than usual, or in general not feeling well.  When this is the case we can worry about infections, inflammation, bladder stones, etc.  I will discuss these problems in more detail in a later blog.

Even if the history doesn't quite fit with a medical problem, it may be suggested to perform a medical work-up to make sure that no problems are seen.  This could include basic bloodwork (complete blood count, blood chemistry, thyroid hormone) and then a more detailed analysis of the urogenital system (urinalysis, urine culture, imaging of the urogenital tract with either radiographs or an ultrasound).

If a medical issue is ruled out, then the problem may be more of a behavioral issue.  Behavioral issues can be broken down further into issues involving marking versus litter box training or aversion issues.  An indication that problems with the litter box may be a marking issue would be if the history includes:

1.) Urine spraying on a vertical surface
2.) Problem started after a change in the household (new roommate, new furniture, recent visit from friends/relatives, new pet)
3.) Accidents occur around a window or door
4.) Accidents occur on owner's bed or clothes
5.) Accidents tend to occur in a similar spot
6.) The pet is defecating in the box, but not urinating in the box.
7.) The pet sometimes urinates in the box, but sometimes urinates outside the box

These histories tend to indicate more of a territorial or anxiety issue and the cat trying to assert it's claim on that particular environment.  This is different than a problem with litter box aversion or training issue.  In these situations, the histories tend to include things like:

1.) There was a recent change to the litter box, litter location, or litter type
2.) There was a traumatic experience when our pet was using the litter box before (loud noise, attacked by another pet, etc)
3.) The litter box is dirty or perceived dirty by the pet (there are not enough litter boxes for the number of cats in the house.  We typically recommend one more box than the number of cats that you have)
4.) The cat isn't using the litter box for both urination and defecation
5.) The litter box is covered or in a high traffic area of the house
6.) There is a new pet or another pet or person (small child) bothering the pet when they are trying to go

Depending on which problem is determined most likely, we can then determine a treatment plan.  For territorial issues there are a number of medications that can be tried to help with the problem.  Most of the medications tend to run in the anti-anxiety family and can include amitriptyline, fluoxetine, or buspar.  There are also pheromone treatment options that can sometimes work (Feliway).

In cases where there is a litter box aversion, then the solution is more along fixing the perceived problem with the litter box.  This could include adding a litter box, changing locations, cleaning the box more frequently, or switching back to the previous litter.  In some cases, people have confined their pet to a small kennel with the litter box and once their cat is using the box on a regular basis, they will give them more freedom by allowing in a small bathroom, then small room, then the house.

Urinating outside the box can be a very frustrating issue for both clients and veterinarians.  The important thing to remember is that many times the answer is not straight forward and trying different treatments/solutions may be needed.  Give it time and hopefully the problem will be solved.

My Cat or Dog is What?

Cryptorchidism is a condition where one or both of the testicles are not in their correct position.  Instead of being in the scrotum, they are either in the inguinal canal (where the leg meets the belly) or inside the abdomen.  It is much more common to happen in dogs, but as I recently was exposed to (2 cats in 2 months) it can also occur in cats as well.  I should first explain how this happens and then will discuss what should be done about it and why.

The testicles develop in the abdomen near the kidneys.  In the late stages of the fetus and then after a puppy or kitten is born the testicles make a slow descent from the abdomen, through the inguinal canal (small opening between muscle layers of the abdomen and leg), and eventually into the scrotum where they will live.  The testicle is essentially attached to the scrotum by a ligamentous structure called the gubernaculum.  This structure responds to certian hormones during the developmental life cycle and pulls the testicle to its normal position.  Typically the testes should be out of the inguinal canal at birth and then by six months should have made their way to the scrotum.

In cases where this process doesn't happen, the pet is consider to be cryptorchid.  Why is this important?   The testes are outside the abdomen because they require a lower temperature for proper sperm development.  When you have a pet that is cryptorchid, the sperm development may not occur correctly and you might have a sterile pet.  This typically isn't a problem except with breeding pets.  The other major issue is that testes not in the scrotum are at a higher risk for cancer development.  The condition is also hereditary.  Because of this the recommendation for cryptorchid pets is to have them neutered. 

In the case of the neuter, the testicle may be located any place along the descent of the testicle.  In many cases the testicle can be palpated in the inguinal canal and a small incision over that area is all that is need to perform the neuter.  In other cases where the testicle is not easily found in the inguinal canal, the veterinarian may need to perform an abdominal exploratory to locate the testicle, as it could be any place from near the kidney to right by the inguinal ring. 

If your pet only has one or no descended testicles, don't panic.  We typically give them until 6 months of age to drop and then if they haven't we can perform a specialized neuter to remove them.

Is my pet getting old?

A common question that I get when seeing patients is how old would my pet be if it were a human.  There are a lot of formulas out there that claim to change your pets age into human years.  Many of these do work fairly well, but as far as figuring out an exact human age I wouldn't put huge faith in them.  What I can tell you is that I see many older dogs and cats and have a general rule of thumb when seeing them:

1. For smaller breed dogs (less than 10-15 lbs) I can routinely see 14-15 year old dogs.  I usually start to classify them as senior around 8-9 years of age.

2. Larger breed dogs (>60-70 lbs) tend not to have as long of a life span and I typically start to call them senior around 6-7 years of age

3. Cats can differ, especially between indoor or outdoor cats.  Indoor cat can live a very long time and I see many 16+ year old cats.  I usually classify them as middle age around 7 years and senior after 10 years.  Outdoor cats tend not to live as long, but I usually classify them the same way.

So, why does it matter when your pet gets older?  Well, just like with people, pets tend to develop medical problems as they age.  They might not show outward signs of problems, but bloodwork can sometimes pick up early signs of problems.  This is why we recommend a senior screening examination for pets determined to be elderly.

What does a seniors screening exam involve?

1.  With dogs, after the exam we run bloodwork that includes a complete blood count, a six panel chemistry (looking at liver, kidney, blood sugar, and protein values), urinalysis, heartworm test, fecal floatation test, and eye pressures.

2. Cats are slightly different and along with an exam we perform a complete blood count, six panel chemistry panel, urinalysis, thryoid values, and fecal floatation test

The reason that we run these tests are to screen for medical problems where we might be able to intervene and prevent further damage or manage the diseases successfully.  For dogs, we worry about liver disease, Cushing's disease, kidney disease and these tests help determine whether a problem is present.  With cats, we are looking for signs of kidney disease, hyperthryoidism, diabetes, or liver disease.

If changes are seen on bloodwork, then your veterinarian can recommend further diagnostic tests that should be pursued to better evaluate for what may be going on.  They can then recommend treatment options to help manage problems that are found.

Make sure to ask your veterinarian about your pet's senior health at your next visit.