Ovine Flashcards
What problems may thin ewes have in a flock?
Decreased ovulation rates, increased foetal resorption, increased deaths, increased perinatal mortality due to smaller lambs and decreased colostrum, metabolic diseases such as pregnancy toxaemia, decreased lamb growth rates, welfare concerns.
What types of disease may cause ill thrift in adult sheep?
Sheep scab, lameness, Johnes, fluke, PGE (haemonchus),teeth problems in old ewes, triplet ewes, gimmers/ewe lambs, Chronic pneumonia (MVV, spa, pasteurellosis), chronic lameness, CLA, chronic abscessation, neoplasia, scrapie etc.
What is Johne’s disease?
Chronic bacterial enteritis of ruminants caused by mycobacterium avium subspecies paratuberculosis. Survives in the environment for months and is difficult to culture. There is a long preclinical stage with reduced production.
What are the clinical signs of Johne’s?
Progressive loss of condition - protein loss, muscle wasting, brought on by stress. Faeces is normal or slightly soft. Usually have a high GI parasite burden. Up to 5% mortality in adult sheep.
What gross pathology will be seen in ovine Johne’s disease?
The terminal ileum may be grossly thickened or congested, difficult to detect, may be pigmented yellow, may affect afferent lymphatics/nodes, and cause ascites etc.
What are the two forms of ovine johne’s disease?
Multibacillary - weak CMI, strong antibody. Numerous Map in macrophages.
Paucibacillary - strong CMI, weak antibody, map sparce or absent.
How can Johne’s be diagnosed?
Faecal smear, Faecal culture (8-14 weeks, sheep strains v poor growth), faecal PCR, Serology - ELISA, AGID, serum proteins.
What protein levels will be seen with chronic fasciolosis?
Hypoalbumin, hyperglobulin.
how is Johne’s trasnmitted?
Oral faecal, in milk, possibly semen, possibly in utero
What are the costs associated to the farmer with Johne’s?
Lost of cull ewe sale, cost of replacement, death /poor growth of lambs from affected ewes.
What are the control methods for Johne’s?
Reducing environmental contamination and spread of infection, limiting introduction of infection, vaccination, eradication, remove clinical disease, don’t keep lambs from affected ewes for breeding, diagnose and remove subclinical disease, farm hygiene, lambing is a high, avoid high stocking rates on bare pastures, purchase sheep from farms known to be free
Describe the gudair vaccination
Killed strain of MAP in oil. Give single cub cut dose 4 weeks to 6 months for replacements. £2-3 per dose.
Describe the problems seen with incisor loss in ewes?
Unable to bite short pasture so unable to raze - malnutrition, poor production and weight loss on marginal grazing and hill pastures.
What is the aetiology of incisor loss?
Repeated bouts of acute gingivitis, recession of gingival margin and damage to periodontal ligament, bacterial involvement, teeth appear elongated, loose then are lost, may take one to four years.
What are the clinical signs of respiratory disease in sheep?
Coughing, nasal discharge, dyspnoea, as well as crackles and wheeses.
How does Parainfluenza virus Type 3 infect sheep?
Most infections appear subclinical or mild but acute high morbidity outbreaks have been recorded. Infection with PI3 predisposes lambs to infection with manheimia haemolytica. Intranasal (cattle) vaccines have demonstrated a reduction in prevalence of pneumonia.
What type of disease does pasteurellosis cause?
Manhaemia haemolytica causes septicaemia in young lambs, pneumonia in growing lambs and mastitis in ewes. Pasteurella trehalosi causes septicaemia in 6-10 month old lambs. P multocida only rarely causes disease.
What are the clinical signs of infection with manhemia haemolytica?
Hyperacute - sudden death
Acute - sudden onset anorexia and dullness, pyrexia, hyperpnoea/dyspnoea, serous ocular and nasal discharges, frothy fluid at mouth in terminal stages. Chronic presentations may lead to ill thrift.
What findings are seen on pathology with manheimia haemolytica infections?
Ecchymoytic haemorrhages over the throat and over the ribs. The lungs are swollen and purple red in hyperacute cases, and the airways contain pink stained froth.
What are the clinical signs of septicaemic pasteurellosis?
This is an important cause of sudden death in lambs up to twelve weeks old. Affected lambs are depressed, easily caught, with injected mucous membranes and marked dyspnoea, most lambs are pyrexic.
What prediposing factors play a role in triggering clinical manheimia haemolytica?
Environmental conditions - extremes of temperature, wet weather, handling stress, PI3 virus, SPA, mycoplasma/bordetella.
What is the treatment for M haemolytica?
Clinical cases - oxytetracycline, NSAID. A decision must be made whether to gather and treat the lambs during an outbreak. handling may trigger further deaths/disease and most acute mortality occurs in the first day or two of the outbreak. Breeding ewes require a primary course four to six weeks apart followed by a booster four to six weeks before lambing often combined with clostridial vacicine.
What is the most common cause of sudden death in lambs between july and december?
Pasteurella trehalosi. confirmation via isolation of large numbers of P trehalosi from lung liver or spleen.
What are other causes of acute death in lambs?
Clostridial disease, ruminal acidosis, redgut (caecal torsion), acute fluke, brassica poisoning, nitrite poisoning, dog worry, phenol dip aspiration, rhododendron poisoning.
When is P trehalosi sudden death most common?
During october november and december. Outbreaks frequently follow movement of lambs onto rape, turnips or improved pastures. Outbreaks start with a few sudden deaths, but the number of deaths then reduces. GI erosions and ulcers caused by dietary change seem to be port of entry for the normal commensal bacteria, leading to septicaemic disease.
What is atypical pneumonia?
A non progressive chronic pneumonia of housed sheep under a year old caused by mycoplasma ovipneumoniae and possibly chlamydia psittaci. Predisposing factors may include PI3 and M haemolytica.
What are the clinical signs of atypical pneumonia?
A chronic soft cough with some mucopus nasal discharge that spreads slowly through a group of lambs. Some dullness and tachypnoea and growth rates are affected. Some lambs may develop a secondary pasteurellosis.
What is the most pathogenic lungworm in sheep?
Dictyocaulus filaria. Deaths are uncommon but may cause outbreaks of coughing and weight loss in the late autumn/early winter. Infection may trigger secondary pasteurellosis.
What other lungworm can infect sheep?
Protostrongylus rufescens - only a problem if very heavy infestation. Muellerius capillaris - more common but no clinical significance.
What is the life cycle of dictyocaulus filaria?
First stage larvae are passed in the faeces which develop to infective L3 on pasture. Spring pastures are inected by overwintered larvae or via faeces of ewes or hoggs. Clinical disease is seen in autumn, with adult worms in the bronchi.
What do Muellerius capillaris look like on gross pathology?
green/grey subpleural nodules in the caudal lung lobes
What do P rufescens look like on gross pathology?
Inhabits the bronchioles causing small yellow/grey granulomas, also in the caudal lobes.
How does chronic suppurative pnuemonia occur in sheep?
follows pneumonia and occurs when pockets of bacterial infection persist and are walled off as chronic abscesses in the lung tissue or pleural space. it may also be caused by bacteramic spread from a septic focus. Bacteria involved may include manhemia haemolytica, arcanobacterium pyogenes, pasteurella and E coli. Other causes of lung abscesses may include CLA and TB.
What are the clinical signs of chronic suppurative pnuemonia in sheep?
Weight loss/ill thrift in individual animals, mild fluctuating pyrexia and normal temperature, dyspnoea, purulent nasal discharge, no respiratory signs, muffling on thoracic auscultation.
What is Jaagsiekte? (SPA)
An infectious tumour condition resulting from infection with a lentivirus, a herpes virus is also involved in the lesions. The incubation period is several months. Disease occurs in 2-4 year old sheep.
What are the clinical signs of SPA?
Loss of body condition, exercise intolerance, serous nasal discharge, episodes of mouth breathing, afebrile, then dyspnoea, tachypnoea, fluid gathers in resp tract and may flow freely when head is loweres, soft cough, fluid sounds may be heard on auscultation.
What do SPA tumours look like on growth pathology?
Tumours are confined to the lungs which are enlarged and heavy. Usually occupy the anteroventral lung fields, are solid and grey and are well demarcated from normal lung tissue. Lesions may contain abscesses or be hidden by extensive pleurisy. The bronchi and trachea contain copious frothy fluid. Tumour cells replace normal alveolar cells.
how is OPA diagnosed?
There are no commercial laboratory tests to support a diagnosis in the live animal. An afebrile wasting respiratory condition which free fluid running from the nostrils when the head is lowered gives a good indication.
What is the main route of transmission of OPA?
Infection is by respiratory aerosol. close confinement during housing or trough feeding increases the rate of spread of infection. Prompt culling of lean or dyspnoeic sheep may slow the spread of infection.
What is maedi visna virus?
A lentivirus infection causing respiratory disease (maedi) nervous disease (visna) mastitis and arthritis.
When do maedi signs occur?
In sheep over three years old. Earliest signs are exercise intolerance, noted during gathering. Affecte sheep stand with the neck extended, increased respiratory rate, flared nostrils and an abdominal component to the breathing. WAsting occurs and dyspnoea becoems obvious even at rest.
what neurological signs are seen with maedi visna?
Visna signs less common. nervous signs including gait abnormalities, e.g dragging a hind limb, knuckling, ataxia, incoordination, collapse and death.
What other clinical symptoms may occur in maedi visna other than respiratory and neurological?
A large number of affected sheep also have an indurative mastitis, identified as a flabby udder with diffuse hardening. milk production is significantly decreased.
Maedi visna arthritis is important in the USa bu has not been identified in the UK. straight legged gait, with swelling most commonly at the carpal joints.
How do maedi lungs appear on PM?
Lungs are firm, rubbery and heavy. They do not collapse.
how is maedivisna diagnosed?
Agar gel diffusion test to detect antibody to the virus. Elisa tests also now developed.
What are the most common causes of ill thrift in weaned lambs?
Poor nutrition, parasitic gastroenteritis, cobalt deficiency, selenium deficiency, liver fluke, other specific infectious and management problems such as respiratory disease, lameness, sheep scab, coccidiosis and border disease.
What should your basic history include when investigating ill thrift in lambs?
Farming system and feed management throughout the year, times of lambing and weaning, lambing percentage and spread, worming regime and anthelmintics used, previous trace element problems and supplements used, observations of scouring, coughing lameness or skin disease, weather conditions.
What are the clinical signs of cobalt deficiency in lambs?
Ill thrift, frequently empty, pot bellied and depressed in appearance, a watery ocular discharge is associated with low grade conjunctivitis, pale and anaemic.
Why is cobalt required by the animal?
for manufacture of vitamin b12 which is required in the liver for utilisation of rumen deprived propionic acid in energy production. Vitamin b12 is also required for the metabolism of certain S amino acids which are necessary for optimum growth and wool production.
When are pasture cobalt concentrations lowest?
Lowest during spring and highest during winter. Pasture cobalt uptake is lowest when pasture growth is rapid and in mature pasture, corresponding with the spring and summer periods. Pasture grown on waterlogged soil has a higher cobalt concentration than pasture grown on well drained soils.
When are clinical signs of cobalt deficiency seen?
In weaned lambs during the summer and in the newborn lambs of deficient dams during the spring.
What is a good method of diagnosing cobalt deficiency?
perform a dose response trial, comparing growth rates of supplemented animals with unsupplemented controls. The two groups need to be grazed and managed under the same conditions, however such an approach is not always practical or appropriate.
What methods of diagnosing cobalt deficiency are there?
Blood vitamin b12 concentrations reflect immediate dietary cobalt, whilst liver vitamin b12 provide a guide to limited continuous body storage. Serum vitamin B12 levels respond within a few days to an improvement in dietary cobalt therefore values must be interpreted with caution. Yarding for a period of more than 6 hours before sampling, liver damage and poor handling can result in elevated samples.
What is Methylmalonic acid?
MMA accumulates in the plasma of cobalt deficient sheep as a result of reduced vitamin b12 coenzyme activity, raised plasma concentrations of MMA can also be used to support a diagnosis of cobalt deficiency, although there are no defined reference values, so MMA concentrations cannot be used to predict the probability of a response to cobalt supplementation.
How can cobalt be supplemented?
Short term through oral drenching, foliage spraying with cobalt sulphate or vitamin b12 injections. Long term supplementation can be achieved using intraruminal cobalt bullets or by pasture top dressing with cobalt sulphate.
What type of virus is border Disease?
A congenital virus disease caused by a pestivirus. Serologically related to BVD in cattle and swine fever in pigs. characteristics of the disease include barren ewes, abortions, mummified foetuses and classical hairy shaker lambs which have excessively long fleeces and abnormal body tremors.
How does border disease cause disease in sheep?
Heathy newborn and adult sheep exposed to BD virus experience only mild often inapparent disease in the process of seroconverting to the virus. The most serious consequences occur when BD virus infects susceptible ewes during pregnancy with the outcome being dependent on the stage of pregnancy when infected.
What does infection before 60days gestation result in in BD?
foetal resorption, abortion or stillbirth. some foetuses may survive and become classical hairy shakers which are PI with virus but negative for antibody.
What happens when sheep are infected with BD between 6- and 85 days of gestation?
variable - some normal lambs but also some with major CNS irregularities and cerebellar hypoplasia. foetal infections after about 85 days are usually met with a competent immune system and lambs are born normal with detectable antibody levels. lambs persistently infected with virus do poorly.
What are the clinical signs of listeriosis in sheep?
Encephalitis is the predominant form in sheep, though abortion and septicaemia also occur. abortion can be caused by L ivanovii and L monocytogenes sensu stricto with the most common source of infection being poorly made silage.
When do abortions usually occur due to listeria?
Any stage but usually in third trimester. abortions due to L monocytogenes have been reported 7 days after consuming infected silage. diagnosis is dificult and relies on isolation of organism.
What is the minimum amount of treatment for scab?
Few flocks are able to remain totally closed so in most cases a minimum of one autumn acaricide treatment is required to mitigate the risk of scab introduction from stray sheep.
when is scab treatment ideally administered?
wait untill all replacement sheep have been introduced but ideally administered before tupping.
handling pens fields or buildings be considered to be a source of re-infestation with sheep scab?
At least 17 days and not used by previously treated animals during this period
How can sheep be treated with plunge dips?
Plunge dipping for one minute in an approved organophosphate or pyrethroid based solution is a proven method for treatment of sheep scab. Sheep should be immersed for one minute with their heads dipped twice and care should be taken to limit faecal or soil contamination of the dipsolution. When correctly applied plunge dips kill any scab mites present with 24 hours/ Pyrethroid scab dips have a nil or short meat withdrawal period but residues in wool.
What mite causes sheep scab?
Psoroptes ovis.
What are the clinical signs of sheep scab?
Mainly a winter disease. Restless sheep, rubbing against posts, soiled areas of wool, tags of fleece, loosing condition, open wounds can occur.
Which systemic endectocides can be used for the treatment of scab?
Two subcutaneous injections of ivermectin seven days apart. or a single IM injection of doramectin. It may be atleast 7 days before all mites are killed and ivermectin provides no significant residual protection against reinfestation. A single subcutaneous injection of moxidectin provides residual protection against sheep scab for atleast 28 days but two injections 10 days apart are recommended for treatment of scab outbreaks.
How can blowflies be controlled?
Freshly dead animals, faecal material and rotting vegetation provide protein for blowflies so the prompt burial of carcasses and attention to general farm hygiene can aid in their control. blow flies prefer a warm moist and sheltered environment so the risk of strike can be reduced by moving sheep to more exposed pasture. The smell of wool grease, presence of foot rot, urine soaked wool, skin disease, scour or infection attracts blowflies to sheep. Shear sheep often.
How can plunge dipping be used to protect against blowfly strike?
plunge dipping in organophosphorus or high cis cypermethrin can provide protection from blowfly strike for 3-8 weeks depending on the product used. Sheep should have at least 3 weeks fleece growth at the time of dipping. Flumethrin plunge dips which are licensed for sheep scab are ineffective for the control of blow fly strike.
How can louse be controlled in sheep?
Shearing significantly reduces the louse burden by removing a large proportion of the lice and exposing those remaining to the lethal effects of dessication. Pyrethroid plunge dips can provide effective louse control. Pyrethroid pour ons disperse around the body in wool grease. They require 6 weeks to disperse around the body and kill lice therefore fail to prevent infection of newborn lambs.
What type of virus is orf?
Parapox virus in the poxvirus family.
What is caseous lymphadenitis?
A contagious skin disease of sheep caused by corynebacterium pseudotuberculosis.
How does transmission of CLA occur?
Directly between sheep during close confinement or indirectly via contaminated shearing equipment, fighting causing skin lesions
What is the clinical presentation of CLA?
Abscessation of superficial LN - parotid, submandibular, popliteal, precrural and prescap. (cutaneous form). spread of infection to LN within the chest and internal organs including lungs, spleen, kidneys and liver, constitutes the visceral or internal form.
How can CLA be treated?
Despite the sensitivity of C pseudotuberculosis to a number of antibiotics therapy is often unsuccessful due to the intracellular site of the bacteria and the fibrous capsule surrounding the lesions. Lancing lesions only results in contamination of the environment thus increasing the potential for disease spread. Abscesses frequently recur after drainage and lavage with antiseptics.
What can fusobacterium necrophorum cause in sheep feet?
Footrot, scald, foot abscess, toe abscess.
Describe the pathogenesis of footrot in sheep.
Wet conditions and trauma of the interdigital skin predispose. Interdigital dermatitis occurs. F necrophorum penetrates the stratum corneum, D nodosus proteases cause hoof separation and allow the deeper penetration of F necrophorum. With virulent strains, under running spreads form axial heel, laterally and anteriorly under sole to abaxial wall and toe.
What are the clinical signs of footrot?
Mixture of interdigital dermatitis, under run heels and severe under run hooves. mild strains only result in separation at the heels and back of the sole, while virulent strains can result in complete separation of the horn of the hoof wall and sole, there is a characteristic smell. In chronic cases there will be a misshapen hoof, trapping dirt and inflammatory exudates. in advanced footrot the sheep will be extremely lame and recumbent for long periods.
What treatment can be used for footrot?
Gentle paring and application of oxytet spray, footbathing with 3% formalin, 10% zinc sulphate, clean feet and dry standing afterwards is important. cure rates of up to 80% feet, but not great against advanced lesions. There is also a vaccination possible which has a therapeutic effect. some respond to first injection. Parenteral antibiotics are effective against advanced lesions, paring is not needed but dry conditions are required 24 hours post treatment. Use oxytet or pen & strep.
How is footrot controlled and prevented?
Aim of control is to achieve low incidence of footrot, low % of early lesions developing into severe lesions, two doses needed for protection with vaccination. 4-6 months protection. Footbaths useful for stopping development of early interdigital lesions into severe lesions. Footparing HAS NO RULE IN PREVENTING FOOTROT.
How can footrot be completely eradicated?
De stocking for 7 days and re stocking with clean sheep. this involves intensive effort during a non transmission phase when all virulent footrot infections should be clinically apparent, and all pastures safe for clean sheep. Cases must be treated or culled, isolated, and non responders culled. Avoid re introduction via purchasing clean replacements, quarantine before adding to flock.
What is interdigital dermatitis in sheep? (scald)
Scald is a major cause of lameness, and the first stage in the pathogenesis of footrot and septic pedal arthritis. It is caused by F necrophorum infection alone and does not require D nodosus. Moist conditions, trauma caused by long wet grass is often the predisposing factor. Straw bedding may play a similar role in housed ewes.
What are the clinical signs of interdigital dermatitis (scald)
Sheep are lame on one or more foot. interdigital skin is inflamed and swolen, layer of white necrotic material, may progress to erosions of ID skin tissue, no under running of horn, no smell. Lameness can persist for several months if untreated.
What is the treatment of scald in sheep?
Oxytetracycline sprays, move to dry pastures, management of areas around troughs and gates, zinc sulphate or formalin footbaths followed by dry standing for 1 hour.
What is ovine digital dermatitis? (new varient footrot)
A virulent rapidly spreading foot disease similar to digital dermatitis in cattle. An association has been made with motile spirochaetes.
What are the clinical signs of new varient footrot?
High morbidity rate, severe lameness, initially full thickness skin ulceration at coronary band, hoof wall under run from coronary band and often shed to expose the sensitive laminae which may bleed profusely. 1cm areas of hair loss and ulceration sometimes seen on skin below fetlock joints.
How can ODD be treated?
Lesions heal quickly after topical treatment with oxytetracycline sprays. response to foot trimming and footbathing in formalin or zinc sulphate is poor. footbathing for 20 minutes in tylosin or lincomycin antibiotic solutions followed by dry standing appears to be effective for prevention and treatment of ovine digital dermatitis.
How can dietary energy supply relative to metaboilc demands be accurately determined during late gestation?
By measuring ewes serum or plasma 3-OH butyrate concentration. increased values reflect ineffcient fatty acid utilisation caused by high glucose demand from developing foetuses not matched by dietary propionate glucogenic amino acid supply.
When should ewes be blood sampled and body condition scored?
four to five weeks before start of lambing time thereby allowing sufficient time to implement dietary changes. Ewe lambs and gimmers should be avoided as they have more singletons and may give a skewed population. a random sample of 15-20 ewes should be blood sampled.
What is the target value for 3-OH butyrate in sheep?
Target below 1mmol/l. 3-OH butyrate concentrations above 1.6mmol/l in individual ewes represent severe energy underfeeding with the likelihood of pregnancy toxaemia, 3-OH butyrate concentrations greater than 3.0mmol/l are consistent with a diagnosis of ovine pregnancy toxaemia.
How can protein status in pre partum ewes be evaluated?
Blood samples can also be analysed for BUN which indicates short term protein intake and albumin which reflects longer term protein status. Care must be exercised with the interpretation of these parameters as recent feeding can increase BUN concentration. Lw BUN usually indicates a shortage of rumen degradable protein.
What happens to serum albumin in ewes during late gestation?
Serum albumin concentrations usually fall during the last month of gestation as immunoglobulins are manufactured and accumulate in the udder thus serum albumin concs in the region of 26-30g/l are normal during last month of the gestation.
When must ewes be vaccinated for clostridial disease?
Four weeks before lambing. Vaccinate as two separate groups with later lambing ewes one week to 10 days later than those lambing during first week.
What does maternal undernutrition result in?
Inadequate placental development which causes poor oxygen, nutrient and electrolyte transfer and ultimately results in poor lamb birth weights. Long term foetal hypoxaemia inhibits the new born lambs capacity for thermoregulation thereby increasing its susceptibility to hypothermia. Severe maternal under nutrition during the final six weeks of pregnancy results in the birth of hypoglycaemic lambs with poor accumulations of liver glycogen and brown fat and in poor udder development and colostrum production.
What happens during dystocia?
Compression of the umbilical cord, protracted labour or trauma to the foetal central nervous system results in short term, usually reversible hypoxaemia, parturient deaths result from acute anoxia of vital centres of the CNS or from the compounding effect of parturition hypoxaemia on pre existing foetal hypoxia due to placental insufficiency. Maintenance of body temperature, teat searching and suckling behaviour are inhibited in surviving lambs. Soft tissue trauma occuring during parturition and subsequent infection may compromise maternal behaviour.
What are the causes of dystocia?
Poor maternal pelvic conformation, foetal oversize, malpresented lambs, partial uterine inertia in polytocous ewes, vaginal prolapse, ringwomb and unskilled shepherding.
How much colostrum does an average 5kg lamb require?
around 1Litre of colostrum during first 24 hours. Failure of the neonatal lamb to suckle or failure of the newly lambed ewe to provide adequate colostrum results in starvation and poor passive immunity to the disease.
What are the maternal reasons which could cause lamb starvation?
Genotype, inexperience, undernutrition, dystocia, concurrent diseases, mastitis, multiple births.
What are the lamb related reasons which could cause lamb starvation?
genotype, multiple litters, birth stress, prenatal malnutrition, hypothermia (dont suckle), infectious disease.
What extrinsic reasons on farm could lead to lamb starvation?
High stocking density of lambing ewes, disturbance of lambing or newly lambed ewes, human interference, poor pasture availability near to the lambing site, exposure.
At what temperature do lambs become hypothermic?
Normal temp - 39-40C - healthy lamb exhibiting normal suckling behaviour. rectal temp 37-39 - weak, still capable of following the dam and suckling. rectal temp
What is the treatment for moderate hypothermia? (37-39C)
dry thoroughly, ensure a colostrum or milk feed, return to ewe, supervise closely.
What is the treatment for severely hypothermic lambs under 5 hours old?
Dry thoroughly, warm to >37C, give a colostrum feed at a rate of 50ml/kg, warm to 39C, return to the ewe, monitor closely and check dam for milk supply or poor maternal behaviour.
What is the treatment for severely hypothermic lambs over 5hours old?
Inject intraperitoneal 20% glucose at a rate of 10ml/kg, dry thoroughly, warm to 37C, give a colostrum feed at a rate of 50ml/kg, warm to 39C, return to the ewe, monitor closely, check dam for milk supply.
Why should lambs over 5 hours old be given intraperitoneal glucose before warming?
Severely hypothermic lambs over 5hours old are hypoglycaemic, warming results in increased cerebral metabolism which rapidly leads to convulsions, coma and death if the hypoglycaemia is not corrected by intraperitoneal administration of glucose. oral administration of fluids to hypothermic lambs causes regurgitation and inhalation asphyxia or pneumonia.
What is watery mouth?
A disease of 1-3 day old lambs characterised by lethargy, profuse salivation and abdominal distension. Usually highest in intensive indoor lambing flocks of prolific ewes.
What are the clinical signs of watery mouth?
Lamb is depressed, anorexic, mouth is cold and commissures of lips and lower jaw are wet due to drooling of saliva, dehydrated with abdominal distension, cold extremities, scleral blood vessels dilated and ocular mucous membranes are congested.
How can watery mouth be treated?
Intravenous flunixin meglumine, oral dextrose electrolyte solutions, enemas of metoclopramide and broad spectrum systemic antibiotics.
How can watery mouth be prevented?
Correc nutrition of pregnant ewe, management of abortion and dystocia, adequate supervision to ensure all lambs suckle and receive colostrum, maintenance of a clean lambing environment, prophylactic use of oral aminoglycoside antibiotics administered to all lambs within 15 minutes of birth.
How does cryptosporidiosis affect lambs?
Cryptosporidium parvum is not species specific and is potentially zoonotic. Infection causes villous atrophy of the distal small intestine, leading to malabsorption. Rarely causes severe in disease in lambs but if environmental oocyst contamination is high or lambs are other wise compromised or stressed then the organism may cause acute onset, pale green coloured watery and occasionally blood stained diarrhoea in lambs between 2 and 20 days old.
How do outbreaks of salmonellosis occur in lambs?
rare - usually follow the purchase of infected carrier sheep or calves. most cases are caused by salmonella typhimurum or salmonella dublin.
What is the pathogenesis of salmonella spp?
They cause severe intestinal inflammation destroying the absorptive capacity and stimulating secretion. They are also invasive leading to bacteraemia and infection of other organ systems. Endotoxins are released into the systemic circulation on bacterial death resulting in depression, circulatory failure and cardiovascular collapse. the clinical signs are depression and profuse green/brown coloured blood stained diarrhoea with variable pyrexia, dehydration and dyspnoea, rapidly progressing to recumbency and death.
How can diagnosis of salmonella be confirmed?
Diagnosis of salmonella confirmed by faecal culture or culture from liver, gall bladder, small intestine and mesenteric lymph nodes at PM examination.
How does E coli cause disease in lambs?
Enterogenic E coli posess K99 adherence pili which enable attachment to the intestinal mucosa. A stable toxin is produced which causes severe watery, brown coloured diarrhoea. The disease is uncommon and only affects lambs less than 48 hours old. Most lambs die unless prompt fluid therapy is administered.
How do non specific bacteraemias occur in lambs?
In colostrum deprived lambs, tonsilar or enteroinvasion by E coli, P haemolytica and P multocida, arcanobacterium pyogenes, staph and strep from a contaminated environment may be followed by multiplication in other organ systems and subsequent polyarthritis, omphalophlebitis, endocarditis or meningitis.
How does meningitis affect lambs?
Usually occurs 2-4 weeks old. isolation from dam and failure to suckle with episceral congestion, lack of suck reflex, weakness, altered gait and depression extending to stupor but hyperaesthesia to auditory and tactile stimuli. Opisthotonus is observed during the agonal stages of the disease.
What is joint ill and how does this appear in lambs?
Polyarthritis may occur in lambs as young as 5 days old and is characterised by sudden onset lameness with pain, heat and flutuating swelling of several limb joints, leading to poor suckling behaviour and ill thrift. At PM examination, incised joints contain pus, synovial membranes are thickened and congested and articular surfaces eroded.
Which pathogen is usually identified in joint ill in lowland flocks?
Streptococcus dysgalactiae
How does navel ill occur in lambs?
May follow bacteraemia or infection of the umbilical vessels and urachus form a contaminated environment. affected lambs may adopt a hunched back stance with a poor body condition and hollow flanks due to poor suckling behaviour. the navel is moist, swollen and painful and may exude a purulent material.
What is Erysipelothrix rhusopathiae and how does it cause disease in lambs?
It is a bacteria that has a wide host range and can survive for long periods in the soil, especially at low temperatures. Recently born lambs acquire the infection in the same way they acquire other forms of joint ill. A bacteraemia results in organisms settling in the joints, where they cause a fibrinopurulent polyarthritis in addition to osteomyelitis and in some cases endocarditis. Morbidity can reach 40% although mortality is low. affected lambs are stiff and may be pyrexic.
What is the treatment for E rhusopathiae?
high doses of parenteral penicillin is effective in the early stages. in flocks with a recognised problem, vaccination of the dam with two doses of bacterin 4-6 weeks apart in the first year and one booster dose 3-4 weeks before lambing is effective.
What does navel infection with F. necrophorum result in in lambs?
Characteristic white spot, 2-10 mm diameter abscesses in the liver and secondary spread to joints and lungs.
What are the signs of iodine deficiency in lambs?
Goitre, pot bellied, wool is scant and lacks crimp. lambs from the same litter can be afefcted to different extremes. Typically high lamb losses occur during adverse weather conditions due to starvation or stillbirths where the foetal membranes still cover the lambs nose. this is due to the role of iodine in thyroid hormones in foetal maturation and thermoregulation.
What radio of thyroid:body weight suggests flock needs iodine supplementation?
A production response to iodine supplementation is likely when ratio of thyroid:body weight of newborn lambs exceeds 0.4g/kg.
