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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.