Sudden death in growing lambs

Question 1

Pulpy Kidney

• facts (3)
• CS (4)

Answer 1

• Cl. perfingens type D
• enterotoxaemia
• sudden death in non-immune lambs 4 weeks - 8 months old (often the bigger and better lambs!)

If alive:

• sever depression
• abdominal pain
• grinding teeth
• neurological signs

Question 2

Pulpy kidney

• pathogenesis (5)
• CS (4)
• Dx

Answer 2

• organism is present in the gut and multilies at a high rate in the presence of undifested CHO (milk)
• Prototoxin is cleaved to give active e toxin in the presence of trypsin and absence of antibody
• toxin gets into blood via increased vascular permeability and fixes to liver, kidney and brain cells
• causes liquefactive necrosis, perivascular oedema and haemorrhage in CNS
• mobilisation of hepatic glycogen stores

CS:

• hyperglycaemia
• glycosuria
• nervous changes
• death

Dx: Hx of rich feeding

• PM
• smears, gram stain, culture, PCR of bacteria/ toxin gene
• toxin detectable by ELISA

Question 3

Braxy

• agent
• pathogenesis
• Dx (3)
• pathology (3)

Answer 3

Cl. Septicum

young, non immune sheep eat frosted forage which damages abomasal wall –> Cl. Septicum produces a toxin –> forms pores (inserts into cells and lyses them causing the release of K and haemoglobin

Dx:

• history of frost and no vaccination
• PM
• gram stain

Pathology:

• abomasitis, ambomasal, duodenal walls thickened, oedematous, haemorrhage and necrosis
• excess turbid peritoneal fluid
• epicardial petechiae

Question 4

Black’s Disease (5)

Answer 4

• sheep of all ages
• affect liver
• associated with migration of immature liver fluke in the liver
• late autumn/winter
• sudden death

Question 5

Tetnus

• Facts (2)
• CS (3)
• Tx (2)

Answer 5

• Cl. tetani
• associated with docking/castration

CS:

• generalised stiffness and rigidity of limbs
• unable to swallow or eructate
• progression to convulsions

Tx: tetanus antitoxin and penicillin (early cases only)

Question 6

Cl. sodelli

• presentation (3)
• pathology (2)
• Tx

Answer 6

• Primary pathogen of sheep intestine
• acute abomastitis in lambs 3-10 weeks
• sudden death and abomastitis in finishing lambs 6-12 months

Pathology:

• morphologically distinct hairpin cells
• two toxins: haemolysin and lethal
  - -> lethal glucosylates RAS, RAC ad RAL

Tx: penicillin

Question 7

M. haemolytica (2)

Answer 7

• sudden death in lambs up to 12 weeks old

- if alive : depressed, febrile (>42 oC), toxic MM and dyspnoea

Question 8

P. Trehalosi (3)

Answer 8

• sudden death in recently weaned lambs
• stress conditions
• if alive : depressed, febrile (>42 oC), toxic MM and dyspnoea

Question 9

M haemolytic and P trehalosi

• pathology (6)
• Tx

Answer 9

• lungs oedematous and congested
• enlarged haemorrhagic LNs
• widespread petecchiae, serosal surfaces , epicardium, kidnyes
• focal necrotising hepatitis
• upper alimentary tract erosions
• pleurisy and pericarditis

Tx: oxytetracyclines? vaccinate at same time as clostridia

Question 10

Acidosis

• CS (6)
• Px
• Tx

Answer 10

CS:

• sudden death
• anorexia and bruxism
• distended abdomen and ruminal stasis
• severe metabolic acidosis –> tachypnoea and dyspnoea
• diarrhoea
• dehydration

Px: gradually , over 3 weeks, introduce grain concentrate before giving ad lib

Tx: cost effective? bicarbonate, encourgae feeding forage