Diagnosing Odor in Cats

Skin odor is a common manifestation of a skin infection. The most common skin infections in cats are bacterial (superficial pyoderma) and yeast (Malassezia dermatitis) infections. Skin discharge and/or odor can indicate that your cat may be suffering from a skin infection.

What are bacterial and yeast infections?

Bacterial infections are usually caused by bacteria that are part of the normal flora of the skin (e.g. Staphylococcus intermedius). For this reason, the infection is not contagious to other animals. In cats that have abnormal skin (e.g. allergies) the bacteria increases in number and causes red bumps (papules) and rancid odor. Some cats with bacterial skin infections also develop excessive shedding, patchy hair loss, and scaling. If the infection is left untreated, it may reach deeper parts of the skin. In these cases, nodules that have a purulent (pus) discharge develop. In most cases skin infections are secondary, so it is very important to pursue an underlying cause. Failure to do so will result in reoccurring infections.

Animals often develop a yeast infection (Malassezia dermatitis), which manifests itself as greasy, red, itchy skin with a rancid odor. Areas most commonly affected include the ventral neck, groin, armpits (axillae), and perineal areas. This infection is also secondary to an underlying disease, most commonly allergies. In some cats this may be a consequence of chronic antibiotic and steroid therapy but, as a general rule, cats do not develop yeast infections after antibiotic therapy as commonly as people do.

Diagnosis of Skin Discharge or Odor in Cats

• History is very important for the proper diagnosis of skin diseases. Your veterinarian will ask questions regarding the age of onset, progression of the disease, and response to previous treatments.

• Skin cytology provides useful information on the type and severity of infection. Your veterinarian may take samples of skin (e.g. swabs or tape impressions).

• In some cases, a biopsy may be necessary to establish a final diagnosis. Some samples may be used for cultures of various types while others may be sent to a pathologist to obtain more information about the cells that are present in the skin.

Treatment for Bacterial Dermatitis

Treatment for bacterial skin disorders is antibiotics. Some of the more commonly used antibiotics include ampicillin, cephalexin, enrofloxacin, clindamycin, clavulinc acid and sulf based drugs.

The minimum length of therapy for superficial pyoderma is 3 to 4 weeks. The minimum length of therapy for deep pyoderma is 8 weeks. As a rule, therapy should be continued for 2 to 4 weeks beyond the resolution of clinical signs.

Treatment of Malassezia Dermatitis​

Systemic therapy is reserved for severe cases. It is important to note that griseofulvin is not effective against yeasts. Ketoconazole, itraconazole and fluconazole are all effective against Malassezia.

Topical therapy as the sole treatment is only effective in mild cases while severe cases usually require systemic therapy. Selenium sulfide (Selsun Blue®) is a keratolytic, anti-seborrheic, degreasing agent that will kill Malassezia (effective in 65 percent of cases).

Ketoconazole shampoo (Nizoral®) is approved in many countries for the treatment of seborrheic dermatitis in people and is usually effective in killing Malassezia.

Chlorexidine at 2 to 4 percent might be effective against yeasts, 0.5 to 1 percent is not effective.

Miconazole (Dermazole ®, Resi-zole® leave on conditioner) is also effective.

Vinegar/water rinse (1/5 to 1/10) is a cheap and effective long-term maintenance treatment to prevent relapses.

At-Home Care for Cats

You will need to shampoo your cat with medicated shampoos. Benzoyl Peroxide is an excellent antibacterial antibiotic (e.g. Oxydex®, Pyoben® shampoo). Other antifungal shampoos contain miconazole or ketoconazole (e.g. Nizoral® shampoo for dandruff is now available OTC).

Contact time is important when using a medicated shampoo. You should allow a 10 to 15 minutes contact time for the product to be effective. Leave-on products are also available on the market for prolonged efficacy.

You may have to administer oral medications (either antibiotics or antifungal medications) to help treat the infection. Compliance is very important. Some cats may require medications for a prolonged time as skin infections usually take a while to clear. Speak with your veterinarian before administering medication to your pet.

If your cat keeps relapsing with infections, it is important to pursue an underlying cause. This will decrease the frequency of relapses and reduce the risk of resistance to medications used for prolonged periods of time.

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What to do if your pet rabbit is itching and scratching

Rabbits shouldn't scratch themselves any more than you would. If your pet rabbit seems excessively itchy and scratches a lot, it is likely a problem that needs to be addressed. Various issues—from mites to allergies—can cause a rabbit to itch and scratch, but fortunately, these are treatable!

Why Do Rabbits Itch and Scratch?

When an animal experiences severe itching and scratching, it's called pruritus. In a rabbit, it can be due to fur, skin, or ear parasites; dry skin; allergies; or infections. No matter the cause, it's important to take care of it right away for the sake of your rabbit's health and quality of life.

Fur Mites

Cheyletiella parasitivorax are microscopic mites that live in the fur of rabbits. Cheyletiella mites are blood-sucking parasites that bite your rabbit in order to feed, which causes it to itch and scratch.

Fur mites are also referred to as "walking dandruff," because they're often seen moving the dead skin around on rabbits, creating the appearance of mobile skin cells. They may start off in a small area on your rabbit, but if left untreated, they can spread all over its fur, into the environment in which they live, and to other rabbits and pets.

Even if your rabbit never goes outside, it can get fur mites from food or bedding that you bring into your home.

Lice

While not as common as some other parasites, lice do infest rabbits. They're species-specific, so humans and other non-rabbit pets can't get them.

Fleas

Many people don't think that rabbits can get fleas, but the reality is that any pet with fur can. Fleas, like fur mites, are blood-sucking parasites that bite rabbits, which, in turn, causes them to itch and scratch.

Female fleas lay up to 50 eggs every day, so even if you only see one or two adult fleas on your rabbit, they've probably already laid hundreds of eggs. Fleas also bite humans, but female fleas usually can't produce viable eggs when human blood is their only food source.

Indoor rabbits can get fleas just like outdoor rabbits. Other pets in the household can give your rabbit fleas and they can be tracked in from the outdoors. Fleas can also find their own way into homes just like other insects, such as ants.

A flea comb will help you find fleas and flea dirt. Flea dirt is the cylindrical feces that turn red if rubbed with a wet cotton swab. This is a good trick for distinguishing the digested blood from normal environmental dirt.

Dry Skin

Your rabbit may develop dry skin, which can make it itch and scratch. Rooms with very low humidity, dusty environments, poor diets, and bathing your rabbit too often or using inappropriate shampoos can all contribute to dry skin in your pet. If you can determine the cause of the dry skin, then you should be able to reverse it. For temporary relief, ask your vet to recommend a rabbit-safe spray product.

Ear Mites

Psoroptes cuniculiis are ear mites that cause itching and scratching. They can be spread from rabbit to rabbit, so wash your hands after handling a rabbit with itchy ears (and in general!). You may notice hair loss around the ears and/or scabs, or the rabbit's ears may look especially dirty. A head tilt, a flopped ear, and head shaking are all signs of an ear mite infestation, which doesn't always affect both ears. If you notice any of these signs, take your rabbit to see the veterinarian.

Allergies

Just like people, some rabbits are allergic to certain substances that cause them to itch and scratch. Usually, these allergies are environmental and not food-based, so you can make changes to bedding, litter, cleaning solutions, and air purifiers to make your rabbit more comfortable at home.

Common environmental allergens include the dust in certain litters or in the rabbit's hay, as well as laundry softeners and detergents used on blankets.

Rabbits can also be allergic to parasites such as fur mites and fleas. This will make an infestation of these pests even more irritating to your pet.

Skin Irritants

In addition to allergies, rabbits may be irritated by certain products, especially if they aren't meant for rabbits. Shampoos, conditioners, sprays, and air fresheners may all cause skin irritation in your rabbit. If you use a new product, such as a shampoo, and the next day your rabbit is itching, it may be because it was too harsh for your rabbit's skin. This is often the case with products meant for dogs that are used on rabbits.

Ringworm

Caused by two main types of organisms (Trichophyton mentagrophytes and Microsporum canis), ringworm is a fungal infection that causes hair loss, itching, and red "ringworm" lesions in rabbits. People can also contract ringworm from a rabbit.

The main cause of ringworm, as well as mites and fleas, is direct contact with an infected rabbit. When you bring a new rabbit into your home, keep it separate from your other rabbits until you're sure it doesn't have an infection. Rabbits can also contract ringworm from dirty environments and brushes that were used on an infected rabbit.

Skin Infections

Urine scald and feces that have remained in prolonged contact with your rabbit's skin and generally unclean environments may cause your rabbit to develop a skin infection. The infected area may become red, inflamed, and very itchy and should be treated right away.

Treating Itching and Scratching for Rabbits

The methods used to treat a rabbit's itching and scratching depend on the cause. However, a number of problems are solved through the same means.

• Fur mites are highly contagious to other rabbits. If you have other pets in your house and your rabbit is diagnosed with Cheyletiella mites, take care not to spread these parasites to other animals. Wash your hands after handling your rabbit and throw away the food and bedding in its cage.

• For fur and ear mites, lice, and fleas, freeze all unused food and bedding that you purchased from a pet store or online. The parasites can be brought into your home with such items, so freezing them before use is also a good way to prevent an infestation.

• If your exotics vet diagnoses your rabbit with mites, she will most likely prescribe a medication such as Selamectin, which will kill the infestation without harming your rabbit. Over-the-counter products are typically not safe for rabbits, and you should always consult your veterinarian prior to administering such products.

• If you find fleas or flea dirt on your rabbit, treat your rabbit and all the other furry pets in the household with a safe medication, just as you would for fur mites.4 You will also need to clean and treat the environment. Some rabbit owners use boric acid powder in their carpeting and various flea sprays and bombs sold at pet stores. If you choose to use these products, make sure your rabbit is out of the room you're treating for at least 24 hours.

• If your rabbit has environmental allergies, use fragrance-free fabric softeners and detergents meant for babies or sensitive skin to wash its blankets. If symptoms continue, look to other possible allergens in your rabbit's environment—for example, dust or pollen from an open window in spring or summer—and try to correct these.

• Ringworm is usually treated with topical ointments or oral medication prescribed by your exotics vet.

• Skin infections typically require prescription medications. An anti-itch spray is available that's safe to use on rabbits, but if the root of the problem isn't addressed, the spray merely provides temporary relief.

How to Prevent Itching and Scratching

Often, your rabbit's itchiness can be prevented by keeping its environment clean. The freezing recommendation for any rabbit supplies is an excellent place to begin as is the use of fragrance-free laundry products for any washable rabbit bedding.

Beyond these, be sure that your rabbit's cage is as clean as possible. Daily and weekly upkeep can make a significant difference in the health of your pet and prevent many skin infections. When bathing your rabbit, use only products designed specifically for rabbits.

It's also a good idea to regularly examine your rabbit's fur. This will help you to easily recognize any abnormalities and take treatment steps immediately, which can prevent an infestation, ear, or skin problem from getting worse.
At the same time, take precautions for any other pets in your home, using products such as flea preventives on a regular basis. Take care about exposing your rabbit to other animals that could transmit any of these issues as well, especially if it's kept outside or allowed to go outside.

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Food Allergies in Dogs: Symptoms and Treatment

Dogs, like people, can have allergies to certain foods. In fact, food allergies are one of the most common allergic reactions known to affect our canine friends. When your dog is allergic to a particular food, their immune system responds to the food as it might respond to an infection or bee sting, producing antibodies that in turn cause the symptoms associated with the allergic response.

We all know dogs are “garbage guts” and will eat, well, a wide range of stuff. Sometimes it’s hard to distinguish a little upset stomach from an allergic reaction to food. When symptoms such as diarrhea persist, allergies may be the cause. These symptoms usually take time to develop, since your dog’s immune response takes time to produce the antibodies that cause the allergic response.

Symptoms of Food Allergies in Dogs

The most common symptoms of a food allergy are:

• Itching

• Hair loss

• Skin infection

Less common symptoms include:

• Vomiting

• Diarrhea

• Weight loss

• Lethargy

• Hyperactivity

Sometimes, dogs show more aggression because of their discomfort.

The most common foods that cause canine food allergies are proteins such as lamb, beef, chicken, and eggs. In addition, some dogs can be allergic to soy or gluten, which is found in wheat and similar grains. Some dogs may be allergic to preservatives or other food additives, as well.

When a dog eats a food they are allergic to, a vicious cycle occurs: they eat, their body produces an allergic reaction, and they become symptomatic, i.e., they itch, has diarrhea, or may vomit—which is why it is so important to identify the food for which they are having the reaction to. Frustrating, right?

Diagnosing Food Allergies in Dogs

If your veterinarian suspects your dog of having a food allergy, they will perform a thorough physical exam and take a detailed history of your dog’s food intake and activities. In addition, your veterinarian may recommend routine diagnostics to rule out other causes of your dog’s symptoms.

Your veterinarian will likely recommend a strict hypoallergenic diet trial for at least 2–3 months to see if it alleviates your dog’s symptoms. The suggested diet cannot contain any ingredients your dog has been recently eating; there are several specifically designed diets to help prevent food allergies. During the food trial, it is critical that your dog does not get any treats or supplements unless approved by your veterinarian.

Treatment for Dogs With Food Allergies

The best treatment for food allergies is avoidance. Once you’ve identified the food your four-legged friend is allergic to, you will be able to avoid it in the future and help your dog live an allergy-free life. Unfortunately, there is no way to prevent your dog from developing food allergies.

If you have questions about canine food allergies, please talk with your veterinarian—the best resource when it comes to the health and well-being of your best friend.

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What Pet Owners Should Know About Food Allergies

You've heard it before. Limited Ingredient Diets. Grain-Free. Allergen-Free. Animal byproduct free. The majority of these companies suggest that these dog food formulas may be helpful for pets with allergies. How true are these claims, though?

As it turns out, food allergies are not as common as many pet food companies and websites may like for you to think. And while food allergies are one possible cause for your dog’s itchy skin, ear infections, or your cat’s diarrhea—there are many more likely causes which may have nothing to do with the food

What is a food allergy?

Food allergies occur when an animal’s immune system misidentifies a protein from an ingredient in their food as an invader rather than a food item and mounts an immune response. The end result of this response can be itchy skin or ear and skin infections in some pets, while it may cause vomiting or diarrhea in others. Some unlucky pets will have both skin and gastrointestinal symptoms. However, food allergies have to be distinguished from numerous other more common causes of these issues.

What are other causes of gastrointestinal signs in dogs and cats?

There are dozens of causes of gastrointestinal issues in dogs and cats – parasites, viruses, bacterial infections, pancreatitis, eating something they shouldn’t, and many others. For pets that have symptoms only on certain diets, it could be due to a food allergy, but it could also be due to an intolerance. For instance, the food may have too much fat, too much or too little fiber, or have other properties or ingredients that don’t agree with that particular pet but aren’t due to an allergy. An appointment with your veterinarian will help narrow down the issue(s) at hand.

What are other causes of itching, and skin and ear infections?

The most common cause of itching, skin infections, and ear infections in both dogs and cats are fleas, allergies to fleas, and environmental allergies – dust mites, pollen, grasses. Both flea allergies and environmental allergies are MUCH more common in pets than food allergies but flea, environmental, and food allergies can all have similar symptoms.

Diagnosis of food allergies

One of the most frustrating things about food allergies is that there really isn’t an easy test. While many tests – using blood, saliva, and even hair – that can be performed by your veterinarian or purchased by a pet owner online (and even sometimes shockingly, through a Groupon!) advertise that they can diagnose food allergies or “sensitivities”, there is no proof that they work. None of the currently available tests have been shown to be accurate – that non-allergic dogs test negative and allergic dogs (and only allergic dogs) test positive. In fact, multiple studies have shown that these kinds of tests are not very helpful in diagnosing food allergies, despite their widespread use for this purpose. Research results presented at a veterinary dermatology conference even showed that some tests “diagnosed” plain water and stuffed animal “fur” as having food allergies.

The “gold standard” or best method that we currently have, for diagnosing food allergies is the dietary elimination trial. This means feeding your pet a diet purchased through a veterinarian or carefully made at home that contains only a few ingredients (typically one protein and one carbohydrate plus necessary fats, vitamins, and minerals) that your pet has never been fed before or that are hydrolyzed (where the proteins are broken down into very small pieces that can hide from the immune system) or purified to remove the parts that are likely to cause allergies. This diet is then fed as the only food or flavored thing to go into your pet's mouth for a minimum of a month or more, depending on your pet's medical history and issues. If your pet’s signs dramatically improve during the trial, then to confirm a food allergy, your pet then has to go back to the old diet again. A quick relapse is suggestive of an allergy to an ingredient in the old diet. You then go back to the test diet until things get better again before trying one ingredient from the old diet at a time until you identify the specific foods that trigger the problem. Many people switch diets and their pets’ signs improve, but they never re-challenge, so we can’t know if it was coincidence or the diet that actually helped the pet! We see this commonly when the seasons change – pet owners assume it was the diet that caused the improvement in their pet’s allergies when actually it is because seasonal allergens – such as certain pollens – are much reduced.

The “allergy diet” myth

There are no diets that are completely “hypoallergenic”, meaning that they will not cause allergies. The closest we have to this kind of a diet are the hydrolyzed diets that can be purchased through veterinarians. Dogs and cats can be allergic to pretty much any protein or carbohydrate ingredient that can be found in pet food. Feeding a diet with duck, kangaroo, lamb, or venison doesn’t prevent food allergies, it just makes it likely that if your pet develops one, it will be to that protein instead of something more common like pork or chicken. Likewise, there is no evidence that continually changing (rotating) diet ingredients prevents food allergies, but it definitely can limit diet choices to try to diagnose them (since every ingredient your pet has eaten before is no longer available to be used in a dietary elimination trial).

What foods are associated with the most allergies in pets?

While the overall percentage of dogs and cats that have food allergies is low, there are some ingredients that are associated with more of the confirmed cases than others. The most commonly reported food allergies in dogs and cats are chicken, beef, dairy, and egg (and fish for cats). There is nothing particularly special about these ingredients other than they have been the most common ingredients in pet foods for the past few decades, so both cats and dogs often have been exposed to them a lot. What surprises many pet owners is that grains are actually uncommon causes of food allergies – most pets are allergic to animal proteins! Yes, the occasional pet is allergic to a specific grain, or even another plant-sourced ingredient such as potato, or even carrot, but this is less common than an allergy to an animal protein. Unfortunately, this information doesn’t prevent hundreds of companies from advertising their grain-free diets as being good for pets with allergies. Many companies also advertise gluten-free diets for pets. Gluten allergies seem to be extremely rare in pets, having been clearly documented only in Irish Setter dogs, possibly in Border Terrier dogs, and never in cats.

Do I have to use a diet from my vet for a diet trial?

Many companies make over-the-counter diets that they market as being good for dogs with allergies, but they often don’t live up to the hype. Many of these so-called “limited ingredient diets” contain more than 1 protein and 1 carbohydrate source. They may contain fruits and vegetables, alfalfa, kelp, or other ingredients that could interfere with a diet trial. Even those that only have 1 protein and 1 carbohydrate as well as the necessary vitamins and minerals listed on the bag may still contaminated with other ingredients. Several studies recently have shown that large proportions of over-the-counter diets contain ingredients (admittedly sometimes in very small amounts) not listed on the label, likely due at least in part to the common industry practice of running one diet after another in the same manufacturing line at the factory, without a thorough cleaning in between (this is like human foods that are labeled as being made in a factory that also processes nuts – even though they don’t contain nuts, they could have nut residues). Because of the high risk of contamination for over-the-counter diets, we strongly recommend using a veterinary diet for your dietary elimination trial (either novel ingredient or hydrolyzed, depending on the individual pet) or a carefully prepared home-cooked diet designed by a board-certified veterinary nutritionist. The best diets for a food trial have 2-3 ingredients plus fat sources (which are very low risk for allergies) and supplements. Diets for a diet trial should never include fruits and vegetables (unless a vegetable like a potato is one of the 2-3 ingredients), herbs, or ingredients such as kelp because they can make it hard to interpret the results if your pet doesn’t improve on the diet.

If your veterinarian diagnoses a food allergy using a dietary elimination trial with a veterinary diet or home-cooked diet, you may be able to manage your pet afterward with specific over-the-counter diets (once the specific allergen is identified), keeping in mind that you could see a flare-up if you unknowingly purchase a contaminated bag.

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