Case studies from the post mortem room

John Fagan SRORegional Veterinary Laboratory

Athlone.

Outline of Talk

• Outline of cases

• Commonly occurring & emerging/unusual conditions.

• Herd Investigation - Case History

• Ask Questions

Fungal Placentitis X 20

Bovine Foetal Culture Results2006 2007 2008

A pyogenes 6.9% 5.8% 5.6%

Salmonella dublin 6.1% 7.0% 4.6%

Bacillus licheniformis 4.1% 4.5% 2.7%

Listeria monocytogenes 1.3% 1.6% 1.8%

Aspergillus spp 0.5% 0.9% 1.2%

Brucella spp 0% 0% 0%

Total 1977 1647 2014

Other Bovine Foetal ResultsAgent 2007 2008

L hardjo No. tested 431 544

No. Positive (>1:100)

14 22

Percentage 3.2% 4.0%

Neospora caninum

No. tested 771 1080

No. Positive 38 65

Percentage 4.9% 6%

BVD virus No. tested 683 812

No. Positive 38 46

Percentage 5.6% 5.7%

Foetal Hydrops

Ovine Abortion

ToxoplasmosisEAE

• Full term stillborn calf• Clinical Signs: deformed, swollen belly.• PME findings

– excess abdominal and pleural fluids,– a large pale fibrotic liver– a defect in the inter-ventricular septum.

Another Cardiac Defect

Thyroid

• Goitre is an indicator of deficient dietary iodine.

• Confirmatory histology - Thyroidal hyperplasia

Failure to supply a history can lead to lesions being missed

eg spinal abscess

SPINAL ABSCESS

Postpartum death in a Calf

• History– Large full term charolais calf – Died 6 hours after an assisted birth in which

hip lock was reported. – Unable to stand and developed respiratory

difficulties prior to death.

Vertebral Column Damage

Vertebral Column Damage

• Arises from:

• Traction on front quarters of calf towards heels of cow while the hips are locked in the pelvis.

6 week old calf

• Clinical Signs: Hooves, tips of ears and tail falling off

• Gross postmortem examination - pericardium was attached to the heart. There were no other lesions.

Results of Laboratory Tests

• Salm dublin was isolated from the gall bladder and faeces.

• Salmonella serology was also positive.

• Histopathological examination showed no specific changes.

• Kidney selenium at 17.80 µmol/kg is normal. (Normal Range 5 - 20 micromoles/kg Wet Matter)

Diagnosis

Chronic Salmonellosis

• A pleasant surprise to be able to isolate Salm dublin from this case.

• Usually fail to get an isolate from these cases.

Circulatory System Conditions

1.5 year old Heifer

Clinical Signs: Sudden Death

Suppurative embolic focal pneumonia.

Posterior vena cava

Posterior vena cava

Liver enlarged & congested

Purulent foci in the kidneys.

Diagnosis

Posterior Vena Cava Thrombosis Aetiology• Rumen acidosis predisposes to liver

abscessation in cattle.• A liver abscess erodes wall of the

posterior vena cava setting up an infected thrombus.

• Septic emboli are released into blood stream which can result in the focal septic pneumonia and kidney abscesses.

PVC Thrombosis (2)

18 month old heifer

• Clinical Signs: Perfect when last seen by herdowner.

• 2nd loss in a week.

• Diet: Grass & meals.

• No vaccinations.

• Condition: V Good Preservation: Poor

• PME Findings - a very large abscess in the inter ventricular septum in the heart.

• A pyogenes isolated from the abscess.

Diagnosis

Myocardial Abscess

Aetiology

• Septic embolus lodged in heart muscle – possibly originating from infected umbilicus.

• Myocardial abscesses have also been associated wit Mycoplasma bovis, Histophilus somni.

Another Myocardial Abscess

4 year old Cow

• Clinical Signs: Stiffness, lameness, repeated photosynthesization.

• PM Findings: – Endocarditis of the tricuspid and pulmonary artery

valves.– Subcutaneous septic foci around both fetlocks, – septic infarcts in the kidneys– focal pneumonia.

• Streptococcus dysgalactiae isolated from the lung & heart.

• Diagnosis: Endocarditis and associated embolism.

Vegetative Endocarditis

Vegetative Endocarditis

Respiratory Tract Conditions

IBR

• Tracheitis, Bronchitis• Secondary bacterial

pneumonia – Pasteurella sp, Mannheimia sp, A pyogenes.

• Antibody positive animals can harbour the virus and spread intermittently.

IBR (Calf)

• 1 month old calf that had been treated for pneumonia, appeared to respond but relapsed & pined.

• PME - AV pneumonia, pulmonary oedema. • PCR Lung – BHV1 positive.• Histopath - foci of coagulative necrosis in the

liver which is consistent with congenital IBR infection.

• Diagnosis: Congenital IBR infection.

Pneumonia - Mannheimia haemolytica

• Antero ventral distribution

• Sharp demarcation.• Grey hepatisation• Fibrinous pleurisy.

• Found in Calves

• Multiple aetiology

Enzootic Pneumonia

Hoose

• Lungs very expanded• Diaphragmatic lobes

affected• Emphysema, oedema,

patchy areas of consolidation in diaphragmatic lobes.

• Hooseworms in airways ? open down to smaller airways

Hoose wormsHoosePre-patent 7-25days pi

Patent 25days + pi

Post patent – worms expelled

Reinfection – affects partially immune adults.

Hoose

• Histopath lesions– Eosinophils – Atelectasis– Hyaline membranes– Type 2 epithelialisation– Fibrosis in chronic

cases– Cross sections of

larvae.

RSV

RSV

Parasitic Pneum

Parasitic Pneum

BRSV

Gross Lesions

• Antero ventral lobe lesions – atelectic & rubbery.

• Diaphragmatic lobe lesions – fail to collapse, oedematous, heavy firm to touch.

BRSV

• Bronchointerstitial pneumonia,

• Necrotizing bronchiolitis

• Bronchiolar and epithelial syncytiae

• Exudative or proliferative alveolitis.

BRSV

BRSV

Fungal Hyphae in Lung

Fungal Septicaemia

• 2 week old calf• PME Findings -

– necrotic enteritis with associated peritonitis.– Echymoses on the surfaces of the rumen,

reticulum and omasum and in the lungs.

• HPE Findings – granulomatous pneumonia with fungal

hyphae evident, thrombi with fungal hyphae in the intestinal wall and a nephrosis.

Conditions affecting the Liver

Fatty Liver• 8 year old cow calved 3

weeks • Sick since calving. • Scour which was sometimes

bloody. No response to treatment

• Others affected in herd – anaemia, low temperatures.

• PME: – Liver was very yellow in

appearance and enlarged. – A cut portion of the liver

floated in water. – Sub cut & pulmonary

oedema– Urine ketone levels - very

high.

• Diagnosis: Fatty liver.

• Black Disease ( Clostridium novyii)– Focal necrotic hepatitis,multiple lesions

• BHU (Clostridium haemolyticum)– Lesion similar to black disease - larger and single– haemoglobinurea

Liver Fluke

Alpaca TB

ALPACA TB

ALPACA TB

Gastro-Enteric Conditions

Mucosal Disease Lesions

• Ulceration– Mouth/pharynx– Oesophagus (boat shaped ulcers)– Abomasum– Small intestine ( peyer’s patches)– Large intestine

• Carcasses with multiple system lesions are worth checking for BVD virus.

Mucosal Disease

Ostertagiasis

Abomasal Ulceration and Perforation

Rumen Fluke

Photo: Cosme Sanchez RO Cork

PME OF 2 YR OLD BULLOCK

• History: Presented severely depressed, apparently choking by the herdowner. Seemed fine the day before.

• PM Findings:– The abomasal mucosa was hyperaemic and

oedematous. The rumenal contents were strong smelling of fermentation.

– The rumen contained large quantities of fodder, grain, soya and what appeared to be fodder beet.

PME OF 2 YR OLD BULLOCK(2)

• Rumen contents pH - 4.9. This value when considered with gross findings is indicative of ruminal acidosis.

• HISTOLOGY:– Severe congestion and haemorrhage in the

kidney cortex.– No other lesions.

• Diagnosis: Ruminal acidosis.

Oesophageal Oesophageal ChokeChoke

Musculo-skeletal system

Limb deformity and joint laxity in newborn calves

• Seen mostly late Spring

• Suckler Herds

• Particularly bad in 2009.

Limb deformity and joint laxity in newborn calves

• has been attributed to various factors, – mineral deficiencies (particularly manganese), – viral infections (especially BVD), – hereditary causes– ingestion of teratogens/mycotoxins,

• The evidence has been equivocal. • Many of these cases are associated with the exclusive feeding of pit

silage • including some hay or rolled barley (25% of total dry matter content)

with the silage has been reported to eliminate/reduce the problem in some herds. (Gunn & Caldow, Vet Rec Aug 12th 2000)

• Another risk factor that has been identified in many cases is the spreading of high levels of lime on grass. This has been associated with low manganese uptake.

Poisons

Copper

• Jaundiced liver

• “Black” kidneys

• Test liver & kidney copper.

Ragwort

• Gross - liver very firm • Histopath

– cirrhosis

• Clin Path – Raised liver enzymes– Low serum albumen– Positive Woolfe test.

Poisons

Lead• Renal & thymic

haemorrhages• Fish like muscle in

hind limbs• Test kidney cortex for

lead content

Cobalt• Over zealous

supplementation in young calves before the rumen is developed.

• Test Liver.

Poisons

Ferns• Multiple

haemorrhages throughout body.

• Clinpath – Low white cell count– Low thrombocytes

Yew Tree• Supportive History• No visible lesions • Yew leaves in rumen

contents.

Emerging Disease

Bleeding Calf Syndrome

• Germany, UK, France, Italy, Holland (1 case in N Ireland)

• Haemorrhagic condition of calves < 1 month old.

• Clinical signs – persistent fever, – excessive bleeding from their mucous

membranes or from the tiniest of cuts in skin. – Some affected calves may die very quickly.

Bleeding Calf Disorder (2)

• The bleeding is caused by almost complete destruction of the bone marrow of the calf

• Most affected calves die.

• Epidemiological investigation ongoing.

• DAFF are offering free post-mortem examinations on calves that are suspicious cases.

Herd Investigation

Multiple Cattle Deaths

• Initial History – cows dying at or just before calving

• Cow PME – dead emphysematous foetus, peritonitis – suspect salmonellosis, no pathogen isolated.

• Vaccination for Salmonellosis recommended.

• Deaths continued

Multiple Cattle Deaths (2)

• PME on Calves –peritonitis

• PMEs on 2 X 2 year old bullocks. Both showed peritonitis with evidence of septicaemia/toxaemia. – Clostridium sordellii was isolated from both.

• Began to consider if there was clostridial involvement.

Taking Stock

• Confusing picture.– Enormous losses– Different age groups affected– On different farms– No pattern to disease outbreaks

• Farm Visit organised

• 4 different outfarms

Farm 1

• Suckler cows and calves grazing• Some cows holding tails out – described as

having been affected.• Cows put into crush to facilitate blood sampling• Unusual smell detected• Rectal examinations revealed:

– Peri vaginal swellings – Damage to rectal mucosa

• Interference with animals suspected.

Outfarm 2

• Carcase of calf present

• On farm PME – – septic peritonitis– Rectum dissected out

• Farmer shown the damaged rectum & notified of suspicions and advised to contact Gardai.

• DVO & Laboratory management notified.

Lessons Learned

If you ever find unusual disease patterns in a herd where things don’t add up bear in mind the possibility of human interference with the animals.