Diagnostics and Therapy in Veterinary Dermatology. Группа авторов
terms with clients. For example, many owners may not consider excessive licking a sign of pruritus. They may answer in the negative when asked “Is your dog itchy?” even if the dog is up half of the night licking its paws. Use wording such as chewing, rubbing, scratching, licking, and shaking. Determine the initial problems (redness, rash, hair loss, color change, bumps, etc.) and disease progression. The client can also provide information about locations of problems, as some (such as pruritus) may not be obvious on physical examination.
Dermatologic cases are frequently chronic and require repeated clinic visits for successful management. The client should provide their interpretation of the patient’s pruritus level at each visit. There are two ways to do this. The first is a numeric rating scale where the owner selects a number from 0 (no itching) to 10 (severe, constant itching). The second is using a visual analog scale, as shown in Figure 2.2. The client makes a mark on the line indicating their pet’s level of pruritus. Having the client reassess the patient’s pruritus at each appointment, and recording this data, can help determine if a patient has responded to therapy. Some clients may get frustrated if they think their pet’s itchiness is not decreasing. However, the evolution of the pruritus score may demonstrate improvement by recording the initially higher pruritus score that they are not remembering.
Environment/Lifestyle
Find out where the patient spends time, e.g. multiple homes, travel, indoors vs. outdoors, and if clinical signs change in specific situations. In particular, the diagnosis of some types of allergies can be supported through historical information about a patient’s clinical signs in different environments. For example, a cat with environmental allergies may have improvement in clinical signs when staying at the client’s secondary home in Canada versus their primary home in Florida. Some atopic dogs will purposefully avoid grassy areas as their clinical signs increase when they walk through grass. Seasonality of signs suggests environmental causes. However, some patients with environmental allergies will have seasonal signs when they are younger that progress to become year‐round as they age. Specific questioning of owners may be needed to discern details like this that can help to direct diagnostics and therapy.
Figure 2.2 A visual analog scale for owners to report their pet’s level of pruritus.
The patient’s lifestyle should also be considered. Travel history, particularly to foreign countries or different climates, is important, as certain infectious diseases are more prevalent in particular areas. Patients that primarily live outdoors will have an increased risk for insect/wild animal bites, solar dermatitis, and exposure to the elements. They may also be under less direct observation by their owners, making it more challenging to get a complete history.
Other Household Members
Finding out about other animals that the patient is exposed to can be helpful. The presence or absence of skin problems, other diseases, and medication used (including flea control) can provide information relevant to the patient. The presence of clinical signs in humans in the household can increase suspicion for zoonotic diseases, e.g. sarcoptic mange.
Diets
Owners should provide information about the patient’s current and previous diet(s). More precise questioning may be needed to find out about any treats or human foods that the animal is given. If a patient has already been on a food‐elimination diet trial, then specifics regarding which diet was used, length of the trial, concurrent medications/supplements (including flea and heartworm prevention) used, how those medications were given (e.g. in cheese, pill pockets), and other snacks should also be evaluated.
Medications
All medications and supplements the patient is on at the time of the appointment should be noted. In addition to standard medications like antibiotics, glucocorticoids, flea‐control products, and heartworm preventatives, supplements and topicals (shampoos, mousses, sprays, wipes, creams, ointments, powders, dips, and collars) should be included. Specifics regarding dose, treatment duration, and method of application should be recorded. Consistency of administration is important as well. Clients may refer the veterinarian to the medical record rather than discuss the specifics of what they are doing. This should be done with caution, as medications may not always be given as directed.
In addition to current medications, previous therapies should be discussed and noted. Clients will be frustrated if asked to repeat a previous therapy without discussing why it is warranted. It makes them doubt the veterinarian and the thoroughness of their understanding of the case. It is also helpful to find out which therapies the client thinks were most effective, and which did not help at all.
Other Problems
It is easy to focus solely on dermatologic issues when they are the primary complaint, but other aspects of the patient’s health are also important. This includes, but is not limited to, a history of sneezing, coughing, runny eyes, excessive thirst, urination, hunger, panting, vomiting, diarrhea, or pain. This information can help focus the differential list and direct diagnostic testing. For example, a 12‐year‐old dachshund with recurrent pyoderma, polyuria, and polydipsia would be suggestive of hyperadrenocorticism. Another example would be a 1.5‐year‐old golden retriever with a history of ear infections and loose stool, which would suggest food hypersensitivity.
Dermatologic Examination
A complete dermatologic examination should be performed on all patients presenting with skin‐related problems. The key to performing a good exam is consistency and completeness. Good habits that are developed when examining common, simple cases (such as flea allergy dermatitis in a young dog) can be crucial when evaluating complicated or confusing cases. Dermatologic exams should be consistent at each visit so that subtle lesions aren’t missed. Taking the time to evaluate each interdigital space, every mucous membrane, the skin around the vulva, the axillae, the ventral neck, and every nail can provide important information about each patient. Patients will need to be rolled over, have their heads, paws, and tails lifted, and their mouths opened. The exam can start with observing the patient at a distance (often while gathering verbal history from the owner). General body condition, hair coat, behavior, and attitude can all be noted. Performing the exam with the owner present is helpful, as information regarding duration and changes in appearance of lesions can be provided in real time.
General Method for a Dermatologic Examination
One common approach to the dermatologic examination is to begin at the nose and work one’s way caudally. All areas of the skin should be palpated and observed, taking care to inspect frequently overlooked locations. The nasal planum should be evaluated for moisture, normal cobblestone architecture, and changes in pigmentation (Figure 2.3). The oral cavity, lips, and eyelid margins should be checked for lesions such as erosions or ulcerations. A patient’s ability to blink should also be confirmed. The head should be lifted so the ventral neck can be evaluated completely, as this area is predisposed to thick skin folds that can contribute to fold dermatitis.
Figure 2.3 Depigmentation, erosion, erythema, and loss of normal cobblestone architecture on the nasal planum of a dog.
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