• Atopy is a common cause of skin problems in dogs, but it is less common in cats.
• Atopy usually develops in animals younger than 3 years, but older pets can also be affected.
• Depending on the underlying cause, clinical signs may occur seasonally or year-round.
• Atopy may respond to medical management, but long-term treatment is often required.   

What Is Atopy?
Atopy, or atopic dermatitis, is sometimes called allergic inhalant dermatitis. Atopy occurs when allergens that are inhaled or that contact the skin cause an allergic reaction in the body. In dogs (and less commonly, cats), this allergic reaction is focused largely in the skin. Animals with atopy become very itchy; the resultant scratching leads to skin injuries and secondary (subsequent) skin infections. Atopy is usually first noticed in dogs younger than 3 years, although older pets can also be affected. Unfortunately, pets that develop atopy are usually plagued by skin problems throughout their lives.

Many types of allergens can cause a pet to develop atopy. A wide variety of pollens, grasses, danders, insect proteins (such as in cockroaches), molds, and even house dust can cause animals to develop atopy. Animals can even develop allergies to multiple allergens at the same time. Once an animal develops atopy, the condition will continue as long as the animal is exposed to the allergen that is the source of the problem.

Signs of Atopy
Although atopy technically involves the entire body, clinical signs tend to involve the skin. Affected areas commonly include the face, armpits, groin, ears, and feet. Persistent itching causes the pet to lick, chew, scratch, and/or rub the skin, causing injury. Secondary bacterial or yeast skin infections are also common in pets with atopy. Clinical signs of atopy can include the following:

• Generalized scratching and rubbing
• Redness of the skin
• Hair loss from repeated biting, licking, chewing, and/or scratching
• Skin rash, infections, and irritation
• Scabs and bleeding
• Unusual odor
• Skin thickening and color changes
• Ear infections
• Scales and crusts on the skin

​Some animals may have several of these clinical signs, whereas others may have only one—perhaps an ear infection.

Diagnosis and Treatment
Diagnosing atopy can be complicated, partly because other skin problems (such as flea allergy dermatitis) can look very similar. Your veterinarian will likely ask you questions about your pet’s medical history to try to determine how long the problem has been going on and whether the problem seems to be seasonal or year-round. Your veterinarian may also want to discuss your pet’s diet and any products that you may be using on your pet or in your home that could be involved. By considering your pet’s medical history, physical examination findings, and medical test results to help rule out other skin conditions (such as skin mites or flea allergy), your veterinarian may be able to make a tentative diagnosis of atopy.  

Allergy Testing and Immunotherapy
Allergy tests can help identify the specific allergens that may be at the root of a pet’s atopic dermatitis. The two types of tests are an intradermal skin test and a serum allergy test.

Intradermal Skin Testing
Intradermal skin testing can sometimes be performed at your veterinarian’s office. However, because the allergens used for this test are very specific (they vary depending on your region of the country), your veterinarian may refer you to a veterinary dermatologist for this test to be performed. Usually, an area of fur is shaved from your pet to expose enough skin to perform the test. Tiny amounts of each test allergen are injected using very small needles just under your pet’s skin in different areas. After a brief waiting period, your veterinarian will examine the injection sites to measure the degree of local allergic response (redness or a small hive). Allergens that your pet is not allergic to will not cause a reaction, and allergens that you pet is allergic to will cause a reaction that corresponds to the severity of the allergy. Pets are monitored carefully during the procedure in case a serious reaction occurs and treatment is required.

Serum Allergy Testing
The other type of allergy testing, serum allergy testing, is becoming more popular. The test is performed at a laboratory using a small blood sample taken from your pet so that your veterinarian does not need to shave your pet or have special allergens on hand. As with intradermal skin testing, the results of serum allergy testing can reveal which allergens are not causing an allergic reaction in your pet, which ones are causing a mild reaction, and which ones are causing a more serious reaction.

Depending on which type of allergy test is performed, you may need to discontinue your pet’s allergy medications for a period of time before the test. Otherwise, the test results may be affected. Your veterinarian will tell you which medications can be used and which ones may need to be discontinued.

Once a list of “problem” allergens is identified, a specialized serum containing small quantities of these allergens can be formulated specifically for your pet. Through injection of small amounts of the allergy serum over time, many pets experience a reduced response to the allergens.

This treatment, called immunotherapy, generally must be continued for several months to years to achieve results. With immunotherapy, the pet owner generally administers the allergy serum injections at home. If you are uncomfortable with giving the injections, ask your veterinary care team if the injections can be given at your veterinarian’s office. The first injections are more diluted, and each following injection has a slightly higher concentration of the allergens. Your veterinarian will schedule the injections according to specific guidelines—more frequently in the beginning, and eventually tapering to one injection every few weeks. Many pets respond to this program. Others may not, especially if they have other underlying conditions. 

Other Treatments
Atopic dermatitis tends to be a long-term condition. Often, a combination of therapies is needed to provide comfort for pets with this condition.    
Removing Allergens From the Environment

Ideally, if your pet is allergic to a specific item, such as wool, removing this item from your pet’s environment may be enough to resolve the allergy. Unfortunately, this is not always possible or practical, as some grasses and trees may be so common where you live that there is no way to reduce or eliminate your pet’s exposure to them. However, in many cases, helpful steps can be taken. For example, if your pet has a dust mite allergy, you should make your home environment as clean and dust free as possible. Some air filters can also help remove dust, pollens, and other airborne allergens from the home. Controlling other factors that can aggravate allergies is also recommended, such as consistent use of flea control products to reduce your pet’s exposure to flea bites.   

Treating the Symptoms
For pets with atopic dermatitis, the itching can be relentless. Immunotherapy and other management options take time to work, so pets need relief in the meantime. Your veterinarian may want to discuss using the following medications to help control your pet’s itching: 

• Steroids—Drugs like prednisone or dexamethasone, which are called corticosteroids, are often used as the first line of defense to relieve itchy skin because they tend to be very effective and safe for short-term use. These medications can be given by injection, by mouth, or as topical ointments or shampoos. Corticosteroids can provide immediate relief but may have undesirable side effects, such as increased appetite, thirst, and urination. In some cases, repeated or long-term use of steroids can be associated with an increased risk of medical problems such as liver problems, adrenal gland problems, and diabetes. For pets with atopy, steroids can often provide excellent short-term relief, but be sure to speak with your veterinarian about long-term options for your pet.   
• Antihistamines—Drugs like diphenhydramine (Benadryl, Johnson & Johnson) have few side effects compared with corticosteroids. However, some pets will not respond to Antihistamines alone.
• Fatty acid supplements—Special fatty acid supplements may help reduce skin inflammation and are often used in combination with other medications.
• Topical treatments—Medicated shampoos, leave-on conditioners, and ointments can relieve your pet’s itching or help with secondary conditions such as fungal infections, bacterial infections, and scaling. Treatment should be repeated frequently for best results, but be sure to follow all label directions carefully. Avoid the use of human products on pets unless they are recommended by your veterinarian.

Specific Treatment
Cyclosporine can be used to control atopic dermatitis in dogs and allergic dermatitis (including atopy) in cats. The medication is given once a day for 4 weeks (4 to 6 weeks in cats, based on response). After that, the dose can be tapered to every other day or twice weekly, as needed to maintain effectiveness. Researchers estimate that over 70% of dogs and cats respond to this treatment; however, cyclosporine can be costly, and its side effects may include stomach upset and diarrhea. Ask your veterinarian if cyclosporine may be a good choice for your pet.

• High doses of aspirin can be poisonous (toxic) to dogs and cats; cats are more susceptible to aspirin toxicosis than dogs are.
• Toxic effects can occur within hours of the pet swallowing aspirin or may take a few days.
• Never administer a medication intended for humans to your pet unless instructed to do so by your veterinarian. 

What Is Aspirin Toxicosis?
Aspirin has been considered a safe and reliable over-the-counter fever and pain medication for decades. Because aspirin is considered very safe, some pet owners give aspirin to their pets. There are also aspirin formulations specifically for dogs. However, high doses of aspirin can be dangerous for dogs and even more hazardous for cats. Aspirin toxicosis occurs when a cat or dog swallows enough of the drug to cause damaging effects in the body.

Aspirin is broken down primarily by the liver, and some of the resulting substances are later eliminated by the kidneys through urine. Because cats lack certain proteins that are needed for the liver to safely break aspirin down, aspirin’s effects last longer in cats than in dogs (5 to 6 times longer). The risk of aspirin toxicosis is also higher in cats.

How Does Aspirin Toxicosis Occur?
Many cases of aspirin toxicosis in dogs and cats are accidental. A pet may find and chew on a bottle of pills or eat a pill that has fallen on the floor. Sadly, some cases occur because pet owners give medication intended for humans to their pet without being instructed to do so by a veterinarian. Some medications meant for humans, like Pepto-Bismol and oil of wintergreen, are related to aspirin and can cause aspirin-like side effects in pets.

There are situations in which your veterinarian may prescribe a specific dosage of aspirin for your dog or cat. Be sure to follow your veterinarian’s dosage directions very carefully, and report any vomiting or other problems right away. 

What Are the Clinical Signs of Aspirin Toxicosis?
Signs of aspirin toxicosis can occur within a few hours; however, some signs can take a few days to appear. The most common side effect of aspirin toxicosis is stomach irritation. In mild cases, this may cause vomiting. In severe cases, it can cause the pet to vomit blood. The irritation can also be severe enough to cause stomach ulcers and stomach perforations (punctures in the stomach wall that allow stomach acid to leak into the abdomen). Aspirin also affects platelets—blood cells that help the body form blood clots and prevent bleeding. Aspirin toxicosis can cause such severe bleeding that blood transfusions can be necessary to save the patient. Aspirin toxicosis can also inhibit blood flow to the kidneys, which can cause kidney failure. Clinical signs associated with aspirin toxicosis can include the following:

• Vomiting (sometimes with blood)
• Diarrhea or black stools
• Dehydration
• Abdominal pain
• Increased respiratory rate
• Pale gums (secondary to blood loss)

Cats can develop anemia because of aspirin’s effects on their bone marrow. Severe liver damage can also occur in cats as a result of aspirin toxicosis.

How Is Aspirin Toxicosis Diagnosed?
Diagnosis of aspirin toxicosis is commonly based on a history of recently chewing or swallowing pills. Your veterinarian may recommend diagnostic testing, such as a chemistry panel and complete blood cell count (CBC), to assess the extent of the damage. If stomach perforation, liver damage, or kidney failure are suspected, additional diagnostic testing is warranted. 

What Is the Treatment and Outcome for Aspirin Toxicosis?
If aspirin toxicosis is recognized right away, vomiting can be induced to remove the drug from the stomach before the body can absorb it. Another option may be to anesthetize the pet to flush out the contents of the stomach. Your veterinarian may also administer a special preparation of liquid activated charcoal to slow absorption of the drug from the stomach and intestines.

There is no specific antidote for aspirin toxicosis. Treatment may include blood transfusions, intravenous fluid therapy, medications to help protect or heal stomach damage, and other medications to help support and stabilize the patient.

Aspirin toxicosis can be fatal. However, pets can survive if the condition is recognized, diagnosed, and treated quickly.

Most cases of aspirin toxicosis are preventable. Never administer medications intended for humans to your pet unless instructed to do so by your veterinarian, and keep all medications in the home secured to help prevent accidental swallowing.

• Antifreeze poisoning occurs when pets drink antifreeze containing ethylene glycol.
• The liver quickly breaks down ethylene glycol into toxic products that can lead to kidney failure and death.
• Even a small amount of antifreeze can be fatal to dogs and cats.
• Antifreeze poisoning is a medical emergency, and early treatment is crucial.
• Signs include: staggering, vomiting, increased drinking and urination, and seizures.
• Diagnosis is generally based on the results of blood and urine tests.
• Treatment may include the induction of vomiting, medications to prevent the absorption and metabolism of ethylene glycol, and fluid therapy.

What Is Antifreeze Poisoning?
Most antifreeze solutions contain high levels of ethylene glycol, an ingredient that, once metabolized, is extremely toxic to dogs and cats. Pets are often attracted to the liquid because of its sweet taste. Even small amounts can be lethal to animals. A cat that walks through spilled antifreeze and then licks its paws may ingest enough to be fatal. As little as 2.5 tablespoons of antifreeze could kill a 20-pound dog.

Once ingested, ethylene glycol is quickly broken down in the liver to other substances that can lead to kidney failure and death within 12 hours to a few days. That’s why antifreeze ingestion is a medical emergency. If you suspect that your pet has consumed antifreeze, contact your veterinarian immediately.

What Are The Signs Of Antifreeze Poisoning?
The signs of antifreeze poisoning vary, depending on the amount of antifreeze the pet drank and length of time since ingestion. Initially, pets may stagger or walk like they are drunk. Other signs include:

• Lethargy (tiredness), depression
• Nausea, salivation (drooling)
• Vomiting (often the fluorescent green color of antifreeze)
• Increased drinking
• Increased urination

As time progresses, signs may include:

• Rapid breathing
• Seizures
• Little or no urination
• Coma

How Is Antifreeze Poisoning Diagnosed?
Antifreeze poisoning is generally diagnosed based on the results of blood and urine tests. However, as kidney failure sets in, these tests may be less accurate. Free-roaming pets that have signs consistent with antifreeze ingestion should be treated as soon as possible.

How Is This Condition Treated?
To be effective, treatment needs to be initiated as soon as possible after antifreeze ingestion. If your pet is seen within an hour of consuming antifreeze, the veterinarian may induce vomiting and possibly anesthetize the animal to flush out the contents of the stomach. They may also administer a liquid solution of activated charcoal to help prevent further absorption of the ethylene glycol.

If it has been longer than an hour since ingestion, the veterinarian will most likely give your pet a medication to help prevent the liver from metabolizing the ethylene glycol. The pet may also be placed on intravenous fluids and other medications to encourage excretion of the toxic substances produced during metabolism of ethylene glycol.

Once kidney failure has begun, it may be difficult to save the animal because the damage from antifreeze is often irreversible.

How Can I Protect My Pet From Antifreeze Poisoning?
There are a number of steps you can take to prevent your pet from drinking antifreeze:

• Do not allow your pet to roam the neighborhood freely.
• Use antifreeze containing propylene glycol, which is less toxic than ethylene glycol.
• Do not allow your pet access to the area when you are draining radiator fluid.
• Clean up all antifreeze spills immediately.
• Store antifreeze containers out of the reach of pets.
• Check your car for antifreeze leaks frequently.

• Any pet can develop an ear infection; underlying allergies or other illnesses are often the cause.
• Bacterial infection generally occurs secondary to the inflammation and unhealthy environment in the ear.
• A typical course of antibiotics can be as brief as 5 to 7 days, or as long as several months. It is best to give all medications as directed for the full course of treatment, even if the ears look better right away.

What Is an Ear Infection?
The medical term for an ear infection is otitis. Ear infections generally begin as inflammation of the skin inside the outer ear canal (the tube-shaped part of the ear visible under the ear flap). Once inflammation is present, discharge, redness, and other characteristics of an ear infection become established. Inflammation of the canal leads to the overgrowth of normal bacteria and yeast that live in the ear; other “opportunistic” bacteria can also take advantage of the inflammation and unhealthy environment inside the ear to establish infection. The overgrowth of these organisms causes more inflammation and other unhealthy changes inside the ear. In some cases, ear infections that start in the outer ear canal can progress to involve the middle ear and inner ear. Deep infections can lead to deafness and other complications.

What Causes Ear Infections?
Any pet can develop otitis regardless of ear shape, exposure to water (swimming), or the amount of hair inside the ear canal. Ear infections in dogs and cats are most often the result of an underlying problem. Many conditions can predispose a pet to developing an ear infection, including the following:

• Allergies (food allergy or inhalant allergy)
• Ear mites
• Polyps or other growths in the ear canal
• Systemic illnesses such as thyroid disease and adrenal gland disease (in dogs)
• Foreign material in the ears, including dirt, sand, or plant material

Ear infections are painful. Some pets with this condition may even try to bite people  who try to touch their ears or head (including their owners). The clinical signs of otitis can vary depending on the severity of the inflammation, but can include the following:

• Shaking the head or rubbing the head and ears on the floor or on furniture
• Scratching the ears
• Discharge from the ears (can sometimes have a very bad odor)
• Redness of the ear canal and ear flap; the ears may also feel warm when touched

Some pets with severe otitis may cry or groan as they rub and scratch their ears. Some pets scratch so severely that their nails create wounds on the skin around their face, neck, and ears. If the otitis is severe or chronic, the outer ear canal can begin to thicken and become deformed. This thickening can make the ear opening very narrow, so cleaning the ears becomes more difficult. Ulcerations on the inside of the ear canal can also result from infection and trauma.

If a chronic or severe otitis progresses to involve the middle or inner ear, more severe clinical signs can occur, including development of a head tilt, incoordination, inability to stand or walk, and increased pain.

Why Are Antibiotics Necessary to Treat Ear Infections?
Once the inflammation associated with an ear infection is established, bacteria (and yeast) can create secondary infections. These infections can be relatively straightforward to diagnose and treat with antibiotics or antifungal medications. Still, the underlying reason for the inflammation must be addressed, or the secondary infections are likely to recur. Diagnosing the underlying cause can be challenging and may require additional testing.

During a physical examination, your veterinarian may use a cotton swab to collect some debris from your pet’s ear. This material can be placed on a slide and examined under a microscope to determine if the infection is due to yeast, bacteria, or mites. Your veterinarian may also recommend bacterial culture and sensitivity testing of the debris found inside your pet’s ear. This information can help determine the best medications to treat the infection.

Your veterinarian will also likely clean your pet’s ears to remove as much debris as possible before treatment begins. Cleaning begins creating a healthier environment inside the ear—an environment that will not continue to support bacterial overgrowth.

How Are Antibiotics Given?
In many cases, antibiotic medication for an ear infection can be applied (usually as an ointment or drops) directly into your pet’s ear. Sometimes, oral antibiotics or antifungal medication (for yeast) may also be recommended. Your veterinarian may also administer an injection of antibiotics in the office to start treating the infection quickly (while oral or topical medication is taking effect). Oral or topical steroids may also be prescribed to help reduce swelling and inflammation and to make your pet more comfortable with having his or her ears handled.

Antibiotics for ear infections are available in many formulations, so notify your veterinarian if you are having problems medicating your pet, because there may be other options available. You should also notify your veterinarian right away if your pet seems to be experiencing any side effects from medication.

A typical course of antibiotics for treating an ear infection can be as brief as 5 to 7 days or as long as several months. In many cases, the ears may start looking better after only a few applications of medication or after only a few doses of oral medication. However, it is advised to give all medications as directed for the full course of treatment. Your veterinarian may recommend recheck exams during the course of treatment, to monitor how well the condition is responding to therapy. Notify your veterinarian right away if your pet’s ears begin to look worse, if the problem seems to return after treatment is completed, or if other signs of illness are observed.

How Can Future Ear Infections Be Prevented?
Once an infection has resolved, regular cleaning helps prevent recurrence by promoting a healthy environment inside the outer ear canal. Never insert a cotton swab into your pet’s ear canal; these swabs can rupture the eardrum, which could lead to additional complications. If you are uncomfortable cleaning your pet’s ears, ask your veterinary team to review ear cleaning procedures with you.

Underlying conditions, such as allergies, should also be addressed to help prevent recurrence of ear infections.

Returning for regular check-ups with your veterinarian is also an important way to track your pet’s progress and catch ear infections early before they have a chance to get firmly reestablished.