Priest Lake Veterinary Hospital Newsletters

Newsletter for May 2003

In this issue:

* New Products
* Eye Problems
* Thunderstorm Anxiety

HERE ARE A COUPLE OF GREAT NEW PRODUCTS FOR YOUR PETS!

Advantix prescription spot on treatment is now available for prevention and treatment of FLEAS, TICKS, AND MOSQUITOS on dogs.

Advantix is a different product from ADVANTAGE, which prevents and kills only fleas.

Advantix repels and kills ticks including Deer Ticks (which cause Lyme disease), American Dog Ticks (which cause Rocky Mountain Spotted Fever), Brown Dog Ticks (which cause Erlichiosis) , and Lone Star Ticks for up to 4 weeks.

Advantix kills 98-100% of the fleas on dogs within 12 hours.

Larval stages of fleas in the dog's surroundings are killed following contact with a treated dog.

Advantix repels and kills moquitos for 4 weeks and is Waterproof.  This product should be used on dogs only.

MALACETIC wet wipes have just been introduced to help control buildup of grease, oil, and dirt in the skin folds of pets. This product is a combination of acetic and boric acid that works very well on breeds predisposed to bacterial and yeast infections. Areas particularly indicated for cleansing are on or around skin folds, lips, ears, feet, rear end, and nasal folds. Malacetic wipes should be a great help to owners of Bulldogs, Chows, Sharpeis, and other breeds with skin fold problems.

ARE THOSE RED EYES JUST ALLERGIES OR SOMETHING MORE SERIOUS?

Many dogs this time of year suffer (just like we do!) from pollen allergies. How can we tell if your pet has simple allergies or some type of medical condition? Read on...

The eyes are a very special organ system; so special in fact, that there are many veterinary ophthalmologists across the nation. Like your family doctor, your veterinarian has been trained in ophthalmology and can handle most routine cases. Since eyes are so delicate and each dog only has two of them, we follow eye cases very closely and refer to our ophthalmologist very quickly if we don't like what we are seeing. You should follow the same guidelines: if you see problems in your dog's eyes, call us immediately.

Most of the problems we see in dogs' eyes are in one of the following areas: the conjunctiva or membranes surrounding the eyes, the cornea or clear outer portion of the eye, the iris or colored portion of the eye and
the fluid that bathes the iris called aqueous humor, the lens, and the retina which is like the film in your camera. In this article, we'll discuss three of the most common ophthalmologic problems: conjunctivitis, glaucoma, and cataracts.


Conjunctivitis

Conjunctivitis, or inflammation of the conjunctiva, produces the common problem of red eye. However, there are many other conditions of the eye that produce a red or irritated eye. Glaucoma, uveitis (inflammation of the interior of the eye), and corneal ulcers will also make the eyes red. If the eye is very painful, enlarged, cloudy, or there is a sudden loss of vision, you are more than likely dealing with something more serious than
conjunctivitis.

There are a lot of causes of conjunctivitis including physical irritation from foreign objects, inverted or everted eyelids (called entropion/ectropion), infections, allergies, immune system diseases, and poor tear production. Many will respond to symptomatic treatment, but often we need to look further into the problem and you know what that means: tests! Bacterial cultures can help identify what bacteria are causing the problem and more importantly, what antibiotics will work and which ones won't. Scrapings can be done to look for irregular cells and can point us towards an allergic, viral, or bacterial cause. Flourescein staining of the
cornea will show if the cornea has an ulcer and should be done before any preparation with cortisone in it is used in the eye. This is because cortisone will make any existing ulcer worse.

Dry eye, or keratoconjunctivitis sicca (called KCS), is probably the most common cause of conjunctivitis. KCS is a deficiency in the production of tears; either the quantity or quality of the tears is affected. KCS results in a thick, usually green or yellow discharge being produced and quite a red eye results. KCS is caused by viruses, toxicity to certain medications, or, most often by the dog's own immune system destroying the tear glands.  KCS is easy to diagnose by using the Schirmer tear test (STT), which is a simple test using strips of special paper to measure tear production. KCS is treated using topical cyclosporine, which both shuts down the immune response and stimulates tear production. It is expensive and usually must be used for life; once the eye responds we can use it at lower doses to save a little money. In addition, we often use artificial tear preparations and antibiotic ointments to provide relief. KCS is a serious condition and can cause blindness if left untreated.


Glaucoma

Glaucoma is seen in a lot of dog breeds; since it occurs in man also, people are familiar with this disease. Some of the more common breeds affected are beagles, cocker spaniels, mini and toy poodles, malteses, shihtzus, and many of the terriers. In glaucoma, the pressure inside the eye (IOP for intraocular pressure) increases. This increased IOP causes severe pain and can lead to blindness from pressure damage to the optic nerve. The IOP goes up because of an imbalance between the production and drainage of aqueous humor, the fluid that bathes and provides nutrition to the eye. It either can be a primary, hereditary disease or can occur secondary to other diseases/conditions.

Glaucomas are categorized as either open or closed angle. This angle is the iridocorneal angle, which is where the iris or colored portion of the eye joins both the lens and the cornea on the side of the globe. This is where
the aqueous fluid leaves the eye; if it can't leave, we've got problems. Yes it is complicated. To see if the angle is open or closed, an ophthalmologist uses a tool called a gonioscope. This is an important part of the equation because closed angle glaucomas don't usually respond to medications but are best treated with surgery.

If the angle is open, a variety of different drugs can be tried. If it is an emergency, intravenous medications will be used. The maintenance medications' aims are to either produce less aqueous humor, help it leave quicker, or both. The drugs that help the humor leave do so primarily by causing the iris to close down making the pupil very small. These are called miotics. A good analogy is an accordion type closet door all bunched
up (pupil open) and then closing it to stretch it out (pupil constricted). The next class of drugs decreases the production of aqueous humor. Some of these are eye drops and some are in pill form. Timolol was widely used and generally thought to be effective, but now we are learning that it needs to be used in much higher doses than in man and these higher doses may have cardiac side effects. Oral drugs such as daranide are also used to lower humor production: these have been in use for over 40 years, have few side effects, and decrease IOP by about 20-30%.

As in most diseases, it is crucial to detect glaucoma early, before damage to the eye and optic nerve occurs. Therefore, if there is any suspicion of glaucoma, we check the IOP. In susceptible breeds, the IOP should be checked annually even in the absence of symptoms with a special hand held tonometer.


Cataracts

Cataracts are very common in dogs. They should not be confused, however, with nuclear sclerosis, which is a normal age related hardening of the lens. A cataract is an abnormal opacification or crystallization of the
lens. Most of the cataracts seen in dogs are hereditary and they usually occur eventually in both eyes although not at the same time or at the same rate. Other causes besides heredity are diabetes, pups fed milk replacers, chemicals, radiation, and trauma.

Cataracts are staged according to the degree of involvement. Incipient cataracts are small cataracts and do not usually affect vision. When it increases to involve more of the lens, it is called an immature cataract;
the retina can still be seen through an ophthalmoscope and the dog may or may not be blind. When the entire lens is cloudy it is a mature cataract, the retina cannot be seen, and these dogs are blind. If the cataract starts
to then get smaller or resorb a little, it is called hypermature. Hypermature cataracts can rarely result in a restoration of vision, but don't count on it. Mature and Hypermature cataracts sometimes leak protein into the front of the eye causing inflammation (flare). Flare can often be controlled by low frequency application of anti-inflammatory drops in the eyes - this can play a big role in preventing glaucoma from occurring in the affected eye.

Cataracts are treated surgically. Over the years, many claims have been made about eye drops that will restore vision and cause cataracts to resorb. None has been proven with scientific data to work; any anecdotal successes were probably hypermature cataracts spontaneously resorbing.  Surgery has been refined over the years; one study showed success rates in dogs rising form 37% in 1961 to currently over 90%. There are four methods:  two involve removing the lens and two involve fragmenting the lens through
a small needle and sucking the remnants out; this is called phacofragmentation or phacoemulsification . This is the more common method used today but it really depends on multiple conditions as to which technique the surgeon chooses.

SPRINGTIME BRINGS THUNDERSTORM ANXIETY IN DOGS

Noise phobia, often manifested as excessive fear during thunderstorms, is a relatively common affliction of dogs. Sadly, it is a problem that leads some frustrated owners to euthanize or give up their dogs. Each Summer we receive many calls from families who feel that they can no longer deal with their pets fearful and sometimes destructive response to thunderstorms. Hopefully the possibility of new treatment options for noise phobia may save some dogs from euthanasia or abandonment.

A fear is classified as a phobia when it is out of proportion to the danger of the real situation. Phobias generally become worse, not better, with repeated exposures. Dogs with mild noise phobia may look anxious during thunderstorms, tremble, hide under the bed or in the bathtub, and be afraid to go out of doors for hours after the storm has passed. If your dog suffers mildly, the best you can do is train him to go to a certain place
in the house where he feels comfortable; some dogs like to go into an open crate, some like the bathtub or shower. If your dog heads to a certain spot and seems calmer, reward him. Severely afflicted pets may soil in the house, destroy furniture, attempt to break through walls or crash through windows, often hurting themselves in frantic efforts to flee the source of their fear. In addition to thunderstorms, dogs may develop noise phobic reactions to fireworks, gunshots and, less commonly, loud engines or sirens.

Some dogs can be taught not to fear thunder and other loud noises. For information on the accepted methods of doing this, see the Behavior Modification section below. For dogs who are resistant to behavior modification, anxiety reducing treatments may offer a solution.

Pharmacological Medications

For dogs who are resistant to behavior modification, anxiety reducing drugs may offer a solution. The two traditionally used tranquilizers for noise phobia are Acepromazine and Valium. "Ace" is classified as a major
tranquilizer and is a strong drug that at effective doses may produce heavy sedation and incoordination. Where thunderstorms are frequent, these side effects may make the drug undesirable. Valium, on the other hand, may not be strong enough to block severe phobic responses and is so short acting that it may not be effective for afternoon thunderstorms when given in the morning by working owners.

Tranxene-SD is a long acting Valium type drug that may be useful for working owners. The initial dose for large dogs is given once a day. All drugs of this class can produce the opposite reaction, a paradoxical
excitability, and should first be given when the owner is at home. If used over a period of time, the dose should be tapered gradually, rather than abruptly discontinued.

A drug that seems to offer promising results in dogs with mild symptoms is buspirone. Initial research seems to indicate that buspirone may not block severe phobic reactions. Other medications include the anti-anxiety
medication alprozolam (Xanax) and a beta-blocker such as propranlol or inderol (which minimizes the dog's physiological, but not emotional, response to fear). "Beta blockers" are commonly used in people and pets for various heart conditions and high blood pressure. It is also taken by some musicians and performers to relieve the symptoms of stage fright.

The latest preferred medication is clomipramine (Clomicalm) which has been approved by the FDA for treating separation anxiety in dogs. This is closely related to amitriptyline, a drug that has had beneficial results on thunder-phobic dogs. Both drugs work to correct the balance of the level of chemicals called neurotransmitters in the brain. Unfortunately, some drugs do have side effects and to get the fullest benefit, thunder-phobic dogs must take anti-anxiety medications from the beginning of the stormy season and extending through the season's duration.

Unfortunately, sedation sometimes is the only way to help a dog with noise phobias. Bear in mind, however, that most drugs do not help a dog recover from his fear or prevent a negative reaction the next time he hears the noise. You have a scared dog that is too drugged to run. Sometimes this is the only option for the owners of dogs who cannot be helped by an other treatments.

Behavior Modification

Two basic techniques of behavior modification are routinely employed in treating dogs with noise phobia: desensitization and counter-conditioning.  Desensitization is the process by which an anxiety producing stimulus, in this case thunder, is presented so subtly as to not produce a fearful response. Very gradually the intensity of the stimulus, or volume of the thunder, is increased, always keeping it below the fear producing
threshold. Counter conditioning is the conditioning of an individual to respond to the feared stimulus with a reaction incompatible with the undesirable response. For example, the dog is encouraged to enjoy delicious
food treats, as the thunder volume increases.

An excellent article written by Victoria Voith D.V.M, Ph.D. and Peter Borcheidt, Ph.D., two leading veterinary behaviorists details the specifics for carrying out a behavior modification program at home. It requires some effort on a family's part, but can offer a successful "cure" if meticulously followed and if it is possible to reproduce an authentic enough stimulus, in this case, a faked thunderstorm, to elicit a fear response in the dog. Herein lies the cause for many treatment failures. It can often be difficult, even in specially designed sound labs complete with high quality loudspeakers, darkened rooms and strobe lights to recreate a sufficiently realistic thunderstorm. (Copies of this article, outlining a detailed, well constructed behavior modification program, may be obtained by requesting Booklet #1110 "Fear of Thunder & Other Loud Noises "from Quaker Professional Services, 585 Hawthorne Court, Galesburg, Illinois 61401). An audio tape available in pet supply stores contains many sound effects. Instructions are included.