Term
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Definition
- staph aureus- present on teats of all ewes and p.haemolytica is present in mouths of young lambs.
- manheimia haemolytics
- caused by: inadequate milk supply, resulting in excessive suckling by lambs and teat injury.
- orf
- cold exposure can predispose to mastitis |
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Term
| Mastitis in ewes Treatment |
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Definition
- antibiotics and anti inflammatory drugs
- seldom succesful in cases where udder is already purple colored
- humane destruction
Prevention
- correct ewe nutrition to ensure adequate milk supply
- management of orf
- dry ewe mastitis tubes/tilmicosin injections |
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Term
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Definition
- Eimeria crandallis and E. ovinoidalis
- 4-8 week old lambs
- also see in older naive lambs
- acute onset diarrhea, dullness, anorexia, dehydration and weight loss affecting a high proportion of the lamb flock. |
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Term
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Definition
Following the ingestion of coccidia oocysts from a contaminated environment, the parasite invades and multiplies several times in the cells of the lining of the intestine, causing epithelial erosion. After a period of 2 – 3 weeks oocysts are shed in the faeces, further contaminating the environment. Under cool and moist conditions many oocysts survive over winter in buildings and on pasture. Oocyst shedding by healthy ewes also contributes to the environmental contamination. Coccidiosis is essentially a disease of intensive husbandry and the severity of disease is proportional to the level of environmental oocyst contamination. Early born lambs may not ingest sufficient oocysts to become clinically affected and develop immunity, but contribute significantly to the contamination of the environment and disease in later born lambs.
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Term
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Definition
- based on history of intensive lamb management and clinical signs.
- GI parasitism is a differential diagnosis
- faecal oocyst counts may support a diagnosis of coccidiosis
- usually confirmed by PM |
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Term
| Managing outbreaks of coccidiosis in lambs |
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Definition
- managed by whole flock treatment with sulphonamide drugs and avoidance of intensive grazing.
-coccidiostat drug decoquinate can be included in lamb creep feed for disease prevention or fed to ewes to reduce their contribution to environmental oocyst contamination.
- Diclazuril can be administered orally to lambs as a single preventive treatment. |
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Term
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Definition
- precipiration of solutes from urine to form a sludge, resulting in blockage of urethra
- usually at the vermiform appendage and sigmoid flexure
- assoc. with intestive concentrate feeding
- – calcium-magnesium phosphate calculi.
– magnesium ammonium phosphate calculi.
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Term
| Urolithiasis clinical signs |
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Definition
- anorexia
- discomfort
- frequent straining and dribbling small amounts of urine
- severe cases- ventral abdomen and prepuce become swollen due to leakage of urine into subcut tissues which eventually slough.
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Term
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Definition
- amputation of the urethral process or by pelvic urethrotomy- long term prognosis is poor because of hydronephrosis.
- prevent further cases
- check rations for phosphate and magnesium levels
- Acidification of the urine by feed withdrawal for 24 hours and daily dosing with 7 – 10 g of ammonium chloride in solution reduces the likelihood of calculus formation. Lambs should have unrestricted access to fresh water at all times.
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Term
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Definition
- economically important caused by Erlichia phagocytophilia
- primary disease is benign in most animals
- profound effect on immune system- within 24 hours of infection- high fever and pronounced neutropaenia, lymphopaenia - white cell numbers return to normal within a few days
- most infected animals become carriers
- prolonged fever may influence spermatogenesis in rams
- potentiation of other infections- louping ill and tick pyaemia
- greatest risk are newborn lambs and bought in pregnant ewes, most young lambs are infected within the first two weeks of life
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Term
| Diagnosis of tickborne fever |
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Definition
- ID of rickettsias in Giemsa stained blood smears
- + serology indicates exposure, but does not confirm the cause of disease |
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Term
| Prevention of tickborne fever |
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Definition
- dipping or applying black-line pour on treatments of flumethrin or high cis cypermethrin when new born lambs are introduced to the hill.
- E. phagocytophilia is sensitive to oxytet
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Term
| Trans-stadial transmission |
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Definition
for a pathogen to get from one host to another, it must enter the feeding tick larva or nymph, and survive to a nymph or adult that will feed on another host.
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Term
| Trans-ovarial transmission |
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Definition
pathogen passes from infected female ticks to her eggs and then larvae.
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Term
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Definition
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ticks are adapted for long survival between feeds and tick borne pathogens survive for these periods from one transmission opportunity to the next.
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– vertebrate hosts act as carriers infecting more ticks.
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Term
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Definition
- 12 species present in the UK
- Ixodes ricinus- most important as a vector of diseases
- 3 host life cycle enables the transmission of disease
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Term
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Definition
- tick feeding activity optimal at >85% humidity and >7C
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Term
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Definition
- feed for around 28 days
- 3 year lifespan
- non-feeding stages require high humidity
- die after 4-6 weeks if unfed
- 1 year interval between feeds
- predilection sites for tick attachment are the head, neck, axillae and groin
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Term
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Definition
ixodid tick transmitted flavivirus infection
- seasonal occurrence reflects seasonal tick activity
- diffuse non suppurative meningoencephalomyelitis
- transient ataxia-sudden death
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Term
| Transmission and pathology of louping ill |
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Definition
- transmission dependent on ixodes ricinus and is linked to the annual periodicity of tick feeding activity.
- older sheep are immune
- Colostrum derived antibodies provide good protection in lambs born to immune ewes, so only lambs acquiring insufficient colostral antibody die in their first spring. Lambs protected by colostral antibodies are fully susceptible during their second spring, so on endemic farms, most losses are in ewe lambs retained for breeding. When sheep from a louping ill free area are introduced to an endemic area, disease can be seen in all ages.
- viral replication occurs in the lymph node draining the site of the tick bite
- animals become viraemic for a period of 3 days before the loupin ill virus enters the purkinje cells of the CNS and clinical signs develop
- serum ab are produced and virus eliminated
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Term
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Definition
- clinical signs
- knowledge of infected tick activity or recent transportation from an infected area
- histo of brain
- virus isolation from brain tissue
- serum ELISA test , + indicates exposure
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Term
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Definition
- remove susceptible sheep at times of tick activity
- tick control
- vaccination : all ewe and ram lambs to be retained for breeding receive a single subcutaneous injection of the vaccine in the autumn or the following spring, before ticks become active.
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– all purchased sheep are vaccinated once, at least 28 days before exposure to the tick infested pasture.
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– blanket vaccination over a period of two years.
- human infection can occur
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Term
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Definition
- bacteraemia and joint ill resulting from injection of staph aureus, by the feeding of I. Ricinus
- spinal abscesses, leading to posterior paresis
- disease is potentiated by the effect of E. phagocytophilia |
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Term
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Definition
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Babesia capreoli (red deer) and Babesia motasi.
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Transmitted by Ixodes ricinus and Haemaphysalis punctata respectively
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Infects red blood cells leading to haemolysis
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Seldom clinically significant in the UK.
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Transovarian infection occurs in ticks, so
transmission is by all stages.
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Diagnosis via detection of Babesia in Giemsa-stained blood smears.
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Treatment
– diminazene aceturate
– imidocarbdiproprionate
• seldom indicated in UK.
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Term
| Louping ill virus is closely related to what |
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Definition
| the tick borne encephalitis virus which is an important cause of human disease in mainland europe |
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Term
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Definition
coxiella burnetti
- spread in sheep is either directly via tick bites or indirected by contact with tick faeces
- infection generally benign
- important zoonosis
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Term
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Definition
Borrelia burgdorferi
0 infected ixodid tick bites
- potentially serious human disease
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Term
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Definition
important as transmitters of pathogens and therefore production losses
- hill improvement
- grazing management during high risks periods
- prevention of tick infestation- diazinon plunge dips- 3-8 wk protection.
- deltamethrin, high-cis cypermethrin or alphacypermethrin pour-ons
• 6, 8 or 12 weeks protection respectively
- fleeced vs. hair covered areas
- Acaricide treatment- young lambs at docking before turning onto the hill
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