Food Trial, Canine

Food Trial Procedure

By Dr. Karen Burgess

There are two specific categories of hypoallergenic diets available. The first contains a “novel” or new protein and carbohydrate source. Since many dogs and cats have now been exposed to lamb, fish, and even venison, common proteins in these diets include duck, rabbit, and kangaroo. Clients often wonder why an over the counter limited ingredient diet is not a viable option. In a recent study three out of four commercial venison diets claiming to contain no soy, poultry, or beef tested positive for at least one of these antigens/proteins. Prescription novel protein diets are manufactured and tested rigorously to ensure no cross contamination.

The second form of hypoallergenic food is made with hydrolyzed protein which is a conventional protein (such as chicken or soy) that has been reduced to a moleculer size that the immune system cannot recognize and thus react to.

Some owners are interested in home cooked hypoallergenic diets. While a viable option, these diets tend to be more labor intensive and end up being more expensive than prescription diets. If using a homemade diet long-term it should be formulated specifically for your pet by a veterinary nutritionist.

Regardless of type of diet used, please consult with your veterinarian regarding appropriate feeding amounts.

Treat suggestions during a food trial:

• Blenderize food trial kibble with water and a little honey into a doughy consistency, ball up to treat size and store on wax paper in a refrigerated plastic container
• Canned version of food trial diet if available
• If using oat based diet, thick cooked Quik oatmeal with a little honey, store as above
• Kongs with food trial kibble or above dough on the inside
• If potato based diet, baked frozen French fries

Food Allergy, Canine

Food Allergy

By Dr. Karen Burgess

What is the difference between food allergy and food sensitivity?
Some pets have food sensitivity instead of a true food allergy. This is a situation where pets do not tolerate a particular food component but are not having a systemic allergic response. An example of a food sensitivity would be eating spoiled food or someone that was lactose intolerant.

What are common signs of food allergy?
The most common symptom associated with dog and cat food allergy is a non-seasonal itchiness that is not due to another cause such as parasites (i.e. fleas, mange). Typically these signs develop prior to one year of age and are non-responsive to steroid therapy. Common signs include recurrent ear infections, facial itching, and peri-anal itching. Repeated skin infections and hair loss may also be noted. Some pets will display gastrointestinal signs (vomiting, diarrhea, weight loss, flatulence) in addition to or instead of skin signs with food allergy.

How is food allergy tested for?
Clinical signs and history (in particular symptoms prior to a year of age) may be highly suggestive of a food allergy. The only true way to diagnose a food allergy is to perform an eight to twelve week food trial using a veterinary approved prescription hypoallergenic diet (see additional information below on Food Trials). If symptoms resolve this is a strong indicator that the pet is allergic to some component in their previous diet. After completion of the food trial, pets are challenged with individual proteins or carbohydrates to see when they again become symptomatic (typically within two weeks of re-exposure). The goal is to determine whether there is an over-the-counter diet that may be acceptable for long-term use. Owners may continue the hypoallergenic diet indefinitely as it can often be difficult to transition successfully to a commercial product. Some companies do offer blood testing for food allergies. These tests are notoriously unreliable with numerous studies showing both false negative and false positive results. An appropriately performed food trial is the only valid way of testing for a food allergy.

What are symptoms of conjunctivitis?
Mild cases of conjunctivitis may appear as increased tearing that is clear or colored in nature. More severe cases can develop swollen pink or red bulging tissue that appears to almost cover the eyeball. The eye may become increasingly painful causing a pet to hold it shut or paw/rub at eye. In severe cases it may be difficult to see any part of the normal eye.

Why do cats and dogs develop conjunctivitis?
There are numerous reasons for the conjunctiva to become inflamed. Infectious causes include viruses and/or bacteria. In some cases infections will develop secondary to some other underlying cause of conjunctival inflammation. For cats viral conjunctivitis is extremely common and closely related to upper respiratory viral infections they are exposed to at a very young age. In several of these situations the cat may recover from the initial infection but the virus remains dormant in their body reappearing later in life at times of stress or illness. Non-infectious causes of conjunctivitis are typically related to the anatomy (size, shape, and location) of the eyeball itself. Dogs often develop a condition where they stop producing tears which then leads to a “dry eye” and secondary conjunctivitis. Some breeds of cats and dogs are more prone to having flat faces or bulging eyes which can change how the eyelid sits against the eye. In these cases eyelashes or facial fur may rub against the eye and conjunctiva causing inflammation. Allergic disease, foreign material caught in the eye, tumors, and immune disease are all additional causes of conjunctivitis.

How is conjunctivitis diagnosed?
A veterinary examination will typically reveal the presence of conjunctivitis. Additional testing of the cornea and tear production may also be necessary. If systemic disease is suspected bloodwork may be recommended. In complicated cases referral to an ophthalmologist may be recommended.

What are treatment options for conjunctivitis?
Definitive treatment of conjunctivitis involves diagnosing the underlying cause for treatment and controlling secondary bacterial infections. This may involve topical drops or ointment, oral medications, eye lubricants, or surgery. It is important to protect the eye from self-trauma by using a protective collar or Elizabethean collar. Pain medication may also be prescribed to help with associated discomfort.

What is the prognosis with conjunctivitis?
Prognosis is directly related to the ability to treat the underlying condition causing the inflammation.