Manual of Common Diseases and Parasites

of Wildlife in Northern British Columbia

Acute: having severe signs and a short course of 12 to 24 hours. Associated terms: peracutely.

Anemia: a reduction in the number of red blood cells or in the amount of the oxygen carrying component of blood, hemoglobin.

Arthritis: inflammation of joint.

Arbovirus: a virus that replicates in an arthropod. The arthropod acts as a vector and transmits the virus to a suitable vertebrate host where replication also occurs.

Arthropod: group of related invertebrate animals with a hard, outer exoskeleton. These include insects, crustaceans, millipedes, centipedes, spiders, ticks, mites, etc.

Bacteria:  single-celled infectious agents, larger than viruses. Bacteria can be free-living or parasitic, disease causing or living in symbiosis with another organism (mutual benefit to both organisms). Some bacteria can produce spores. Associated terms: bacterial disease, bacteriological.

Biopsy: removal and examination of tissues from the living body.

Capsule: a structure made up of fat, cartilage, membranous or fibrous tissue, enveloping another structure, organ or part. Associated terms: encapsulation.

Carrier: an animal that harbours a disease-causing organism in its body, and which appears healthy and does not exhibit outwards signs of disease, thus acting as a carrier or distributor of the disease.

Cervidae: the family of ruminants containing deer, elk and moose.

Corvidae: the family of birds containing jays, crows, ravens, and magpies.

Chronic: persisting for a long time.

Cloaca: common duct for the passage of feces, urine and reproductive products in birds and reptiles. Also called a vent.

Conjunctiva: the delicate membrane lining the eyelids and covering parts of the eyeball.

Connective tissue: body tissue that supports and connects internal organs, forms bone and walls of blood vessels, attaches muscle to bone, and replaces tissues of various types following injury.

Contagious: capable of being transmitted from animal to animal.

Crustacean: a class of arthropods including lobsters, crabs, shrimps, barnacles, etc.

Cyst: a closed sac or capsule containing liquid or a semi-solid substance. Associated terms: encyst.

Clinical sign: observable evidence of abnormalities of structure or function in animals with disease. Associated terms: clinically affected.

Definitive host: the host in which a parasite passes its adult and sexual stages.

Disease: any impairment that interferes with or modifies the performance of normal functions of an organism (Dr. G. Wobeser, WCVM, Saskatoon, SK).

Edema: abnormal accumulation of fluid in regions of the body.

Emaciation: excess leanness; a wasted body condition.

Emerging Disease: a disease with increasing incidence or expected increasing incidence in a defined time period and location. (from: http://education.vetmed.vt.edu/Curriculum/VM9084/pdf/1Elvinger_handout.prn.pdf)

Endemic: present at all times.

Epidermis: the uppermost layer of the skin.

Epizootic: a disease that occurs at a time or place where it normally does not occur, or with a frequency that is substantially greater than that expected for the time period (Wobeser 1994). Synonym to epidemic in humans. 

Fibrous: tissue composed of or containing threadlike fibres. Often associated with scar tissue or chronic reactions.

Flatworms: flattened, leaf-like worms (Platyhelminthes), some of which parasitize blood, eyes, liver, reproductive tract, respiratory system, skin and urinary system.

Fungus: organisms that lack chlorophyll (the pigment of plants), reproduce via spores and are either parasites or feed on decaying organic material. Fungal diseases generally develop slowly, are difficult to diagnose and are rarely fatal.

Gastrointestinal: pertaining to the stomach and intestines.

Hemorrhage: the escape of blood either externally, internally into the skin or other tissues from a ruptured blood vessel.

Immune: being highly resistant to a disease, due to the formation of specialized proteins in blood serum called antibody that is produced in response to foreign antigens. An antigen is any substance that is capable, under appropriate conditions, of inducing a specific immune response.

Immune response: the specific response to substances interpreted by the body as non-self.

Immunity: the condition of not being susceptible to the adverse effects of microorganisms, parasitic worms or to the toxic effect of substances (antigens – see above, Immune) such as bacterial toxins, foreign proteins, etc. Also, security against a particular disease.

Inflammation: localized response of the body to injury or destruction of tissues that serves to “wall off” the injured tissue or keep out pathogens. Signs of inflammation include swelling, redness, heat, and pain.

Intermediate host: the host in which a parasite passes its larval and nonsexual stages.

Lagomorph: hares, rabbits of the order Lagomorpha.

Lesion: tissue damage caused by disease or trauma. Associated terms: wound, injury, sore, ulcer, etc.

Lethargy: a condition of indifference or drowsiness.

Lymph node: accumulations of lymph tissue found in locations throughout the body of mammals and birds where noxious substances such as bacteria and toxins are removed. Lymph nodes play a role in the formation of antibody – specialized proteins produced by the immune system that respond to foreign substances introduced into the body.

Mechanical Transmission: transmission of a disease-causing agent through a contaminated object. Commonly, insects may transfer disease through contaminated body parts rather than being infected themselves.

Mesentery: a thin, membranous sheet attaching various organs to the body wall. 

Microfilaria: the larvae of filarial worms. See also Nematode.

Mite: a small, often microscopic, spider-like parasite that commonly affects the tissues of the skin.

Mucous membrane: the thin, moist layer of skin overlying areas of the body such as the inner portions of eyelids ( conjunctiva), nose and mouth.

Mustelid: a family of carnivorous mammals that live in both aquatic and terrestrial habitats. Species include: otter, sea otter, ferrets, weasels, skunk, badger, mink, ferret, wolverine, etc.

Necrosis: tissue damage caused by cell death.

Necropsy: examination of the body after death to determine the actual cause of death. Also called a postmortem examination or autopsy (in humans).

Neurotoxin: a substance that is poisonous or destructive to nerve tissue.

Nodule: a small mass of tissue in the form of a swelling, knot or protuberance that can be detected by touch.

Paralysis: loss or impairment of motor function in a part due to a lesion in nervous or muscular tissue. Also by analogy, impairment of sensory function.

Passerine: birds belonging to the large group of “perching birds” that include sparrows, finches, buntings, cardinals, crows, jays, ravens, warblers, blackbirds, etc.

Pathogenic: capable of causing disease.

Plaque: a patch or flat area.

Pneumonia: inflammation of lung tissue.

Protozoan: a single-celled organism, often capable of producing disease.

Pus: a protein-rich liquid containing a thin to thick fluid mixed with white blood cells and damaged cells produced in association with inflammation.

Pustule: a small pus-filled lesion of the skin, usually thin-walled and easily ruptured.

Reservoir host: an animal that is infected by a parasite or disease agent, and serves as a source of infection for another species. Associated terms: reservoir of infection.

Roundworm (Nematoda): elongated, cylindrical, unsegmented parasitic worms, tapered at both ends, that inhabit the lower gastrointestinal tract of animals. Some species are free-living and non-parasitic. Associated terms: filarial worm – a type of nematode.

Ruminant: mammals with four chambered stomachs that “chew their cud”.

Septicemia: disease throughout the body associated with disease-causing organisms or the toxins they produce in the blood.

Shock: acute failure of the peripheral circulatory system due to alteration of circulatory control or loss of circulating fluid; marked by low blood pressure, body coldness, and rapid heartbeat.

Spore (bacterial): a dehydrated life-stage of certain bacteria that is highly resistant to prolonged exposure to chemical disinfectants, ultraviolet (UV) light and high-energy radiation such as X-rays, as well as extremes in pH and temperature or drying conditions.

Spore (fungal): the reproductive elements of fungi produced either sexually or asexually.

Subcutaneous: beneath the layers of the skin.

Sylvatic: pertaining to the forest; loosely, “wildlife” or “wild area”.

Tapeworm (Platyhelminthes): long, flattened, segmented parasitic worms that inhabit the gastrointestinal tract of animals.

Tick: blood-sucking parasite closely related to spiders.

Trauma: wound or injury caused by external force.

Tumour: a new growth of tissue in which cell multiplication is uncontrolled and progressive.

Ulcer: a localized removal of dead or inflamed tissue in the upper layers of tissue of an organ or tissue, often circular.

Ungulate: hoofed mammals.

Vector: a “carrier”, an animal (often an Arthropod) that transfers an infective agent from one host to another.

Virus: infectious agents, smaller than bacteria, that invade the cells of hosts and alters their functioning in order to begin replication of virus particles. Viruses are essentially inert outside of a host, and consist solely of genetic material surrounded by a protein coat. Associated terms: viral disease

Zoonosis: infectious diseases of animals that can be transmitted to humans. Associated terms: zoonotic