Diseases of Growing Lambs

What are the ddxs for diarrhoea in lambs?

• Nematodirus battus

• Parasitic Gastroenteritis

• Coccidiois

• Cryptosporidia parvum

• Acidosis

• Clostridium perfingens type B (lamb dysentery)

• E coli

• Salmonella spp.

How does age alter your most likely differentials for diarrhoea in lambs?

What are the clinical signs of cryptosporidium parvum?

• Lambs young (can be end of lambing season because infection buildup)

• Diarrhoea profuse (blood)

• Dehydration

• Can be fatal

How is crypto diagnosed?

• Faecal samples from affected group

• Stain faecal smear

• PM histopath = definitive

How is crypto treated?

• Supportive

• Oral fluids

• Drug treatment- only off license for calves

How do you prevent/ control crypto?

Reduce challenge

• Use different fields/housing for lambing and calving

• In outbreak move to fresh pasture

• Put newborn animals to clean pasture

• Improve hygiene throughout the farm

Improve resilience

• Lamb nutrition

What Eimeria cause coccidiosis in sheep?

• E. crandalis

• E. ovinoidalis

What are the risk factors for coccidiosis?

• Build up infection end of lambing period

• High Stocking Rates

• Inadequate colostrum

• Mixing ages

• Stress

• Concurrent nematodirus infection

What are the clinical signs of coccidiosis?

• Often 4-8 wk old lambs

• Clinical diarrhoea, tenesmus, fever, weight loss, death

• Sub clin- poor growth

How is coccidiosis diagnosed?

• Faecal samples

• Coccidial count

• Helpful to know what species

• But if clin signs + postiive count usually treat

How is coccidiosis treated?

• Diclurazil and Toltrazuril (usually metaphylactically treat group)

• Supportive

• Oral fluids

How is coccidiosis prevented/ controlled?

• Reduce risk factors

• Hygiene of pens and feed troughs

• Stocking rates

• Colostrum intakes

• Nutrition

• Batch rearing- avoid mixing ages and grazing young on used pastures

• Consider prophylactic/metaphylactic treatment at risk time with Vecoxan (Diclurazil) (repeated), Baycox (toltrazuril)

What causes acidosis in growing lambs?

• Rapidly fermentable carbs (fast intake) causes fall in rumen pH

• Lactic acid production

• Rumenitis

• Metabolic acidosis

• Leads to liver abscessation, fungal rumenitis, death

What are the clinical signs of acidosis?

• Sudden death

• Dull depressed reluctant to move, teeth grinding, colic, bloat, ataxic, recumbent

• Dehydration, no rumen sounds, diarrhoea

How is acidosis diagnosed?

• History and clinical signs

• Rumenocentesis pH<5.5

• Rumen liquor no live organsisms

• PM

How is acidosis treated?

• IV fluids 7-10% dehydrated (saline+ bicarb)

• Oral fluids by stomach tube

• Multivits

• Penicillin for 10 days

• Hay

Review feeding

What are the features of bloat in sheep?

• Rumen bloat uncommon in sheep

• Left side distension

• Cause by grain, oesophageal obstruction, legumes (frothy bloat)

What are the ddxs of bloat?

• Hypocalcaemia

• Peritonitis

• Ascites

• Uroperitoneum

How is bloat treated in sheep?

• Stomach tube

• Dimeticone (orally)- antifoaming agent

• Rumen trochar

What causes lamb nephrosis syndrome?

• Consequence of GI infections/ diarrhoea

What are the clinical signs of lamb nephrosis syndrome?

• 2 to 12 weeks of age.

• Lose weight and have chronic diarrhoea.

• Observed standing over water troughs or field drains due to increased thirst.

(Can't treat)

How is lamb nephrosis syndrome diagnosed?

• Inc urea, creanitine and K

• Dec Alb:Glob ratio

• Metabolic acidosis

• Mainly PM- pale and swollen kidneys (toxic tubular necorsis)

List the respiratory diseases that can affect lambs

Pneumonia

• PI3, RSV

• Mycoplasma spp, Manheimia hameolytica, Pasteurella multocida

Lung worm

• Dictyocaulus filaria (at pasture)

What causes pneumonic pasteurellosis?

• URT commensal

• 2° to stress, diseases enter lungs

What are the clinical signs of mannheimia hameolytica=

• Pyrexia

• Mucopurulent nasal discharge,

• Cough, increased respiratory rate, depth, dyspnoea

• Death

What are the PM signs of mannheima haemolytica?

• AV consolidation (ventral)

• Culture

How is mannheima treated?

• 5-7 day treatment of oxyytet, amoxcillin, macrolides

  • Consider group

How is mannheimia haemolytica prevented?

Vaccination

• Hepatavac P

• Ovipast

What agent causes mycoplasma pneumonia? How does it present?

Mycoplasma ovipneumoniae

• Chronic disease

• Cough, slight nasal discharge, , increased RR, depth, dyspnoea

• Housed, pasture over-stocked

How is mycoplasma pneumonia diagnosed, treated and prevented?

• Dx: history clinical signs, BAL, PM

• Tx: oxytet LA/ macrolides (consider group)

• Px: ventillation, hygiene, stocking rates, risk factors

What causes chronic suppurative pneumonia?

Lung abscesses 2° to pneumonia

• T. pyogenes

• M. haemolytica

• P. multocida

What are the clinical signs of chornic suppurative pneumonia?

Weight loss, pyrexia, soft cough, increased RR, nasal discharge

How is chronic suppurative pneumonia diagnosed and treated?

Dx: PM, ultrasound

Tx: poor prgonosis, prolonged penicillin could help

What are the two lungworms of sheep?

Dictyocaulus filaria

Muellerius capillaris (not thought to be significant, but common PM finding)

When is lungworm infection seen? How does it present?

• Summer / autumn

• Lambs at pasture

  • Coughing , increased respiratory rate, depth, dyspnoea

How are lungowrms diagnosed and treated?

• Dx- Baermann

• Tx- Anthelmintic (treat whole group and move to low risk pasture)

What causes trace element deficiencies?

• Soil deficiency leading to pasture deficiency, reducing availability to sheep

• Sometimes interactions between elements

Why does cobalt deficiency cause ill thrift?

• Cobalt is a constituent of vit B12

• Rumen synthesis of vit B12 needs cobalt

• Needed for red blood cell development, amino acid synthesis and energy metabolism

What are the clinical signs of cobalt deficiency?

• Weight loss

• Anaemia

• Slow growth

• Debility

• Weight loss

• Watery eye discharge

How is cobalt deficiecny diagnosed?

– Co/Vit BI2 levels in blood and liver

– Response to Co therapy

How is cobalt deficiency treated?

• Treat group

• Rumen boluses

• Oral drenches

• Vit B12 injections

• Co in creep feed

• Pasture treatment

What are the functions of Se?

• Anti oxidant

• Immune function

What does Se deficiency cause?

• White Muscle Disease

  • – Ill thrift lambs

  • – Weakness, collapse, lame

• • Poor reproductive performance ewes

How is Se deficiency diagnosed adn treated?

Diagnosis- blood sample

Treatment: Oral, injectable , bolus, selenium salts

What is the typical presentation of iodine deficiency

• Typically in pregnant ewe due to pasture problems or grazing brassica

• Late abortions and/ or

• Weakness and death in new born lambs, lambs thyroid goitre, more susceptible to other diseases

What is susceptbility to Cu deficiency dependent on

• Different breeds and soil types

  • Scottish blackface susceptible to deficiency

What does Cu deficiency cause in lambs? How do you prevent it

• Swayback

  • Caused by ewe deficient in pregnancy

• Prevent by treating ewe with copper during pregnancy

What breeds are predisposed to copper poisoning?

• – North Ronaldsay

• – Suffolk

• – Blue Faced Leicester

• – Texels

What are the different presentations of copper poisoning?

• Acute- ingestion of large amounts

• Chronic- builds up in lysosymes and then released cause intravascular haemolysis

What are the clinical signs of copper posioning?

Ataxic, head-pressing, jaundice, haemoglobinuria, recumbency and death

How is copper posioning diagnosed and treated?

• Dx: History clinical signs and P.M

• Tx

  • Sodium calcium EDTA

  • Supportive therapy

  • Group

  • Remove feed source

  • Molybedenum and sulphur added to water

What are the Ddxs for poor growth of individual lambs but whole batch is generally doing well?

• Low birth weight

• Border Disease (Persistently Infected Lamb)

• Congenital Problem

• Neonatal/chronic infection

• Inadequate milk diet

  • triplet, or dam had too little milk,

  • bottle fed, weaned too soon eat grass too soon

What are the Ddxs for poor growth of a whole batch of lambs?

• Inadequate nutrition

• Parasitic disease especially anthelmintic resistance

• Trace element deficiencies

• Pneumonia

• Lameness

  • Chronic joint ill

  • CODD/FR/Scald

• Orf, Scab (skin diseases)