Veterinary Clinical Parasitology

Anne M. Zajac, Gary A. Conboy, Susan E. Little, Mason V. Reichard

• Publisher: Wiley-Blackwell
• Year: 2021
• ISBN:
  9781119300793
• Edition: 9
• Topic: Medicine
• Subtopic: Veterinary Medicine

New edition of the market-leading benchtop reference on the diagnosis of internal and external parasites in animals, including expanded coverage of parasites of reptiles, birds, and other exotic species Veterinary Clinical Parasitology, 9th Edition, allows for a quick and accurate reference to internal and external parasites found in a wide variety of domestic animals and laboratory animal host species. Focusing on the tests and information most relevant to daily veterinary practice, this classic benchtop manual contains a wealth of high-quality images to assist readers in diagnosing parasitic disease and identifying and treating relevant parasites. Contributions by leading experts in veterinary pathobiology and parasitology cover fecal examination for the diagnosis of parasitism, detection of parasites in the blood, diagnosis of arthropod parasites, and more. The latest edition contains fully revised material throughout, including new and expanded information on immunodiagnostic and molecular diagnostic tests, additional parasite-specific material on the benefits and limitations of different test modalities, and increased coverage of reptiles, birds, and other exotic and laboratory animals. New sections include up-to-date information on anthelmintics, antiprotozoals, and other antiparasitic drugs, and challenging case studies that provide insights on situations where identification of parasites is especially difficult. Published under the auspices of the American Association of Veterinary Parasitologists (AAVP), this indispensable clinical manual: * Describes accurate and cost-effective techniques for diagnosiing parasitic infections in animals
* Presents clear and concise information on the distribution, life cycle, and significance of each parasite covered
* Contains hundreds of color clinical images to enable rapid picture-matching and aid in diagnosis
* Offers a spiral-bound format that allows the book to lie flat on the benchtop, ideal for regular use in daily practice
* Features revised content throughout, including new chapters and images, an improved format, an enhanced color scheme, and an updated companion website Veterinary Clinical Parasitology, 9th Edition is an essential resource for practicing veterinarians, veterinary technicians, diagnosticians, researchers, and students in need of a timely and efficient reference on morphologic identification of parasites in different animal species.

CHAPTER 1
Fecal Examination for the Diagnosis of Parasitism

The fecal examination for diagnosis of parasitic infections is one of the most common laboratory procedures performed in veterinary practice. Relatively inexpensive and noninvasive, fecal examination can reveal the presence of parasites in several body systems. Parasites inhabiting the digestive system produce eggs, larvae, or cysts that leave the body of the host by way of the feces. Occasionally, even adult helminth parasites may be seen in feces, especially when the host has enteritis. Parasitic worm eggs or larvae from the respiratory system are usually coughed into the pharynx and swallowed, and they too appear in feces. Mange or scab mites may be licked or nibbled from the skin, thus accounting for their appearance in the feces. Many parasitic forms seen in feces have characteristic morphologic features that, when combined with knowledge of the host, are diagnostic for a particular species of parasite. On the other hand, certain parasites produce similar eggs or oocysts, and cannot be identified to the species level (e.g., many of the strongylid‐type eggs from livestock). Fecal examination may also reveal to a limited extent the status of digestion, as shown by the presence of undigested muscle, starch, or fat droplets.

COLLECTION OF FECAL SAMPLES

Fecal exams should be conducted on fresh fecal material. If fecal samples are submitted to the laboratory after being in the environment for hours or days, fragile protozoan trophozoites will have died and disappeared. The eggs of some nematodes can hatch within a few days in warm weather, and identification of nematode larvae is far more difficult than recognizing the familiar eggs of common species. Also, free‐living nematodes rapidly invade a fecal sample on the ground, and differentiation of hatched parasite larvae from these free‐living species can be time‐consuming and difficult.

Owners of small animals should be instructed to collect at least several grams of feces immediately after observing defecation. This will ensure the proper identification of the sample with the client’s pet (i.e., a sample from a stray animal will not be collected) and that feces rather than vomitus or other material is collected. The limited amount of feces recovered from the rectum on a thermometer or fecal loop should not be relied on for routine parasitologic examination, since many infections that produce only small numbers of eggs will be missed. Owners should be instructed to store fecal samples in the refrigerator if the sample will not be submitted for examination for more than an hour or two after collection.

Feces should be collected directly from the rectum of large animals. This is particularly important when identification of individual animals is needed. Rectal sample...