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Abomasum   The fourth and final part of the stomach of a ruminant
Abscess   A confined collection of pus
Acute   Sudden; an acute infection is one that develops rapidly and is usually of short duration
Albumin   A blood protein which helps to prevent oedema by drawing fluid from the tissues into the blood
Allergenic   Capable of causing allergy (a sudden inflammatory response)
Alternate grazing   The technique of periodically changing the livestock species that graze on a given pasture; reduces parasite loads on pasture since different animals are affected by different parasites
Alveolus   One of the network of tiny spaces in the lung - the site where oxygen is presented to the blood and waste gases are removed for exhalation
Anaemia   Condition of low blood concentration of haemoglobin, the oxygen-carrying protein in red blood cells. Haemoglobin must contain iron to function properly. Continual blood loss can cause iron deficiency anaemia by depleting body iron stores.
Anorexia   Loss of appetite
Anterior   Anterior
Anthelmintic   Drug used to eliminate helminth parasites from the host
Arachnid   Arthropod with two body segments, a fused head and thorax, and an abdomen. The life cycle is one of incomplete metamorphosis. Adults have four pairs of legs and lack both wings and antennae.
Arthropod   Animals with jointed legs and hard external skeletons, includes insects, arachnids, centipedes, crustaceans (crabs, shrimps) and others
Ascites   Fluid accumulation in the abdominal (peritoneal) cavity
Bladder worm   Infective stage of Taenia tapeworm (Cysticercus), Name refers to the fluid filled bladder which surrounds the larval scolex of scoleces
Bots   Larvae of several fly species, particularly Gastrophilus (horse bot), Oestrus (sheep bot), and Dermatobia and Hypodermia (affect cattle and other species)
Bottle Jaw   Fluid accumulation under lower jaw (submandibular oedema)
Bronchi   Larger sized airways of the lungs, which connect the trachea with the smaller airways
Bronchitis   Inflammation of the inner lining of the bronchi
Buccal capsule   Mouth cavity of a nematode
Bursa   A system of expansions of the cuticle at the posterior end of male strongyle nematodes, The bursa is involved in holding the male and female together in copulation; its shape is species characteristic and is used to identify nematodes.
Capillary   One of the tiny blood vessels which form a network in the body tissues
Capitulum   False head of a tick; bears the mouthparts and the probing sensory structures. Its shape is characteristic of the tick species
Carrier   An apparently healthy animal, which is infected with pathogenic organism, the carrier, can transmit the organism to other animals, which may then develop disease.
Cercaria   A free living larval trematode which develops from a sporocyst or redia in snail intermediate hosts.
Cestode   Tapeworm
Chronic   Long standing, a chronic disease is one of that develops slowly and persists for a prolonged time.
Coenurus   Larval form of certain tapeworms: found in the tissues of mammalian intermediate hosts. Consists of a fluid filled bladder with many tapeworm scolices growing on the inner wall.
Colostrum   The first milk secreted at the end of the pregnancy. Colostrum is rich in naturally derived antibiotics, which can transfer temporary immunity to neo-nates.
Complete metamorphosis   The process of development involving dissimilar larval, pupal, and adult stages; occurs in parasitic flies and fleas.
Coprophagous   Feeding on manure
Crutching   Shearing the anal and genital area and the backs and the hind legs of sheep to reduce blowfly attack
Copulation   Mating
Cutaneous   Pertaining to the skin
Cuticle   Outer layer ("skin") of parasite
Cysticercus   Infective stage of a Taenia tapeworm, consisting of fluid filled bladder with a single scolex on its inner wall. When found in the muscles of livestock, these small bladders cause the mottle appearance termed "measles" in meat.
Definitive host   Animal in which a parasite reaches sexual maturity
Dermatitis   Inflammation of the skin
Direct life cycle   Life cycle in which parasites do not require development within an intermediate host
Ear Canker   Acute inflammation of the ear and auditory canal
Ectoparasite   A parasite that lives on the body surface of its host
Eczema   Inflammation of the skin, often accompanied by itching, crusting and scaliness
Embyronated egg   Egg which contains a formed lava
Emphysema   Increased size of the tiny air spaces (alveoli) of the lung to destruction of their walls, a condition which interferes with oxygen uptake by the blood.
Endemic   Present continually in a region or among a certain groups of animals.
Endoparasite   A parasite that lives within the body of its host
Engorgement   Distension of a feeding tick with blood - cannot occur in male hard ticks, which are totally covered by a hard body surface.
Enteritis   Inflammation of the intestine
Epithelium   The tissue layer which covers the skin and lines the inner walls of many body organs, including the digestive tract.
Exudate   Leaking of fluid which covers the skin and lines the inner walls of many body organs, including the digestive tract.
Feed efficiency   The efficiency with which an animal is able to use ingested nutrients for growth
Festoon   Rectangular raised areas separated by grooves - occurs on the posterior edge of hard ticks of certain species
Fibrosis   The formation of fibrous tissue, often as a response to tissue damage
Gastritis   Inflammation of the stomach
Generation time   The time required for completion of the entire life cycle of an organism
Gravid proglottid   A mature tapeworm segment filled with eggs
Helminth   General term for parasite worms, including nematodes, cestodes and trematodes
Haemorrhage   Bleeding
Hermaphroditism   The presence of both male and female productive organs in the same organism which may be capable of reproducing singly
Heterogonic   Alternation of sexual and asexual reproduction in successive generations of an organism
Hexacanth   (synonym: onchosphere) The motile, six hooked, first stage larva of certain tapeworms, stage which hatches from the cestode egg and infects the intermediate host.
Homogonic   Successive generations of an organism, which reproduce in the same manner
Host-specific   Able to parasitise only certain species of animals
Hydatid cyst   The infective stage of the Echinococcus tapeworm, which forms the fluid filled bladder with many invaginated scolices. Parts of the wall pinch off within the capsule and form secondary cysts, or "brood capsules" each with several scolices. A single hydatid cyst can contain thousands of potential tapeworms. Hydatid cysts are found in humans and livestock.
Hypobiosis   Arrested growth or development or larval or adult parasites
Immunity   Resistance to a disease or infection
Incomplete metamorphosis   The development of some arthropods from eggs to adult like nymphs, which moult to become adults. Characteristic of ticks, mites, and lice.
Indirect life cycle   Life cycle in which immature parasitic forms must develop to the infective stage inside an intermediate host
Inflammation   General response of organisms to irritation or injury. The process if characterised by increases blood supply to the area, signs include reddening, swelling, raised temperature and pain.
Inornate tick   Solid coloured, non patterned
Insect   Arthropod with distinct head, thorax and abdomen. One pair of antennae is present on the head and three pairs of legs on the thorax. Wings may or may not be present.
Intermediate host   A host that is necessary for part of the development of an immature parasite.
Iron deficiency anaemia   Anaemia produced by lack of sufficient iron reserves to replace the iron in lost blood.
Jaundice   A condition which can result from damage to the liver, characterised by yellowish skin and whites of the eyes.
Jetting   Forcing of stream of insecticide into the fleece of sheep to saturate the body areas susceptible to blowfly strike
Lumen   The space in the interior of a hollow organ
Lymph   A clear fluid that normally seeps from capillaries into body tissues, flows in the lymph vessels and is eventually returned to the blood
Mange   Skin disease caused by mites, often produces an expanding area of scabby skin which has lost its hair
Metacercaria   The infective stage of a fluke enclosed in a protective cyst that resits adverse environmental conditions. This stage develops from the cercaria and is infective for the principal host
Metacestode   Immature tapeworm which develops from the hexacanth embryo and grows in the intermediate host (mammal)
Miricidium   The first developmental stage larva of a fluke which hatches from the egg and penetrates the intermediate host
Morbidity   The amount of sickness caused by a disease
Mortality   The death rate caused by a disease
Moulting   Process of growth in which a new, expanding skin if formed beneath the old one; the original skin is shed, allowing the parasite to expand in its new skin
Mucosa   The inner layers of the wall of the digestive tract, mucous membranes
Mules' operation   Removing a strip of skin, extending from the tail base to the inner thigh, from each side of the hindquarters of a sheep. When healed, the operation greatly reduces susceptibility of sheep to blowfly strike by stretching the skin of the buttocks, so that it is no longer wetted by urine, reducing its attractiveness to blowflies
Myiasis   Invasion of body tissues by parasitic fly larvae
Necropsy   Autopsy; postmortem examination
Nematodes   Parasitic worms of the class NEMATODA, which includes intestinal roundworms, filarial worms, lungworms, kidney worms, heartworms etc.
Nit   Louse egg
Occult infection   Hidden infection, one in which no eggs or larvae are produced. For example, infections can be occult when only worms of one sex are present of a species that requires mating to produce eggs or larvae. (See hypobiosis)
Oncotic pressure  
Oedema   The force exerted by proteins to draw tissue from the fluids into the blood
One host tick   Tick that completes all its moult on the same individual host animal
Operculum   Lid of cap like structure at one of both ends of certain worm eggs, ie, Trichuris, and fluke; the larval parasite emerges from the egg at the operculum.
Organophosphate   A substance that can interfere with the function of the nervous systems of some parasites and host animals by inhibiting the enzyme cholinesterase.
Ornate   Coloured, patterned
Ovoviviparous   Laying or deposition of an egg which contains larva
Parasite worry   Annoyance and nervousness caused by parasites
Paratenic host   An animal that carries a parasite principal host. The parasite does not develop inside the paratenic host. The principal; host may become infected by eating the infected paratenic host.
Parthenogenesis   The laying of fertile eggs by a female without the need for fertilisation by a male
Parturition   Giving birth
Pasture rotation   Alternating the ares on which animals graze, allowing time for parasites contaminating pasture to die off before animals are grazed on that land again
Prepatent disease   Disease produced by a larval or immature adult parasites before the parasites are producing eggs
Prepatent period   The period from the time the larvae enter the host until the time the adult female worms begin to lay eggs
Primary blowfly   Blowflies which initiate strike on susceptible sheep. Damage from primary fly larvae make sheep attractive to secondary blowflies
Proboscis   The structure at the anterior end of an organism permitting the attachment and / or feeding
Proglottid   Tapeworm segment
Pyriform (piriform) apparatus   The inner membrane of the eggs of certain tapeworms which is often pear shaped and bears hooks
Rays   Finger like structures which support the copulatory bursa
Redia   Trematode stage in the intermediate host which develops from the sporocyst, and which becomes the cercaria. Rediae may have the ability to divide
Rumen   The first four compartments of the stomach of a cow or sheep. The rumen is a large chamber that serves as a fermentation vat for microbial digestion of feed stuffs
Safe pasture   Pasture on which infective larvae are present in numbers below that necessary to damage animals
Scolex: (pl scolices)   The "head" of a cestode; the part which attaches to the host and generates proglottids
Scutum   A hard plate or shield on the upper body surface behind the capitulum of hard ticks. The scutum is much more extensive in male than in female ticks
Sebaceous glands   Oil glands of the skin and hair follicles
Secondary blowfly   Attack by blowflies which lay eggs only in tissue that has been damaged by a first, or primary, blowfly strike
Seed ticks   Tiny tick larvae before their first blood meal
Segmented egg   Egg within which the inner mass has divided into cells
Self cure   Elimination of parasites from a host as the result of the development of immunity to the parasites
Sheath   Outer protective layer; ensheathed larvae retain an unshed cuticle from a previous moult
Site of predilection   The location in a host animal of adults of a given parasite type
Somatic   Pertaining to the body tissues
Somatic migration   Migration of larvae through the tissues of a host's body
Spicules   Long, slender, rigid structures at the posterior end of male nematodes, serve to align the male with the female and to keep the female genital pore open
Sporocyst   Trematode stage which develops inside the intermediate host from the miracidium; may be capable of multiplication within the intermediate host
Spring rise   The increase in egg production from worms in the spring months; leads to increased numbers of infective larvae on the pastures
Sputum   Mucus coughed from the lungs
Strike   Myiasis, particularly blowfly larval infestation of sheep
Strobila   Body of a tapeworm; composed of maturing proglottids
Strongyle-type egg   Egg form laid by a number of nematodes of the Order STRONGYLOIDEA, characterised by oval shape, thin, smooth wall, and an inner segmented cell mass
Subcutaneous   Under the skin
Systemic   Distributed throughout the body, as in the blood
Therapeutic index   The margin of safety of a drug; the difference between the dose that kills parasites and the dose that harms the host
Three host tick   Tick that seeks a new host animal for a blood meal after each of its three moults
Tick paralysis   An ascending paralysis associated with the engorgement of female ticks; probably caused by a toxin in the saliva of a tick
Toxin   Poisonous or noxious material
Trachea   Windpipe; extends from the mouth area to the lungs, where it connects with the bronchi
Tracheal migration   Migration pattern characteristic of many nematode species. Larvae in the blood break through the long alveoli walls into the airways and are coughed up and swallowed
Transovarian transmission   Passage of a micro organism into eggs within an infected female host
Transfer host   Paratenic host
Trematode   Any parasitic animal organism belonging to the Class TREMATODA, including flukes
Two host ticks   Tick that remains on one host for the larval and nymphal stages, drops off to moult on an adult, and seeks a second h host on which to take another blood meal and copulate
Unthrifty   Failing to grow or develop normally, because of disease
Ventral   Lower, or toward the belly
Viviparous   Giving birth to living young
Wool break   Cessation of wool growth for a brief period causing a breakage of the fibres at the point where growth was interrupted


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