Red meat inspection and gross pathology Flashcards
List the statutory meat inspection protocols
Visual
Palpation
Incision
Variable with species and age
ex. Pigs & bovines <8 month: Visual inspection by default
Describe meat inspection in bovine >8mo, of the head, tongue and throat
- Incision and examination of the retropharyngeal lymph nodes, external masseters, 2 parallel incisions to the mandible, and the internal masseters
- When there are indications of a possible risk to human health, animal health or animal welfare: Incision and examination of the sub-maxillary and parotid lymph nodes; palpation of the tongue and fauces
Describe meat inspection in bovine >8mo, of the trachea, oesophagus and lungs
- Incision and examination of the bronchial and mediastinal lymph nodes, palpation of lungs
- When there are indications of a possible risk to human health, animal health or animal welfare: Incision of the bronchial and mediastinal lymph nodes; lengthwise opening of the trachea and the main branches of the bronchi; the lungs shall be incised in their posterior third, perpendicular to their main axes if lungs for human consumption
Describe meat inspection in bovine >8mo, of the pericardium and heart
Only when there are indications of a possible risk to human health, animal health or animal welfare
- Lengthways incision of the heart so as to open the ventricles and cut through the interventricular septum
Describe meat inspection in bovine >8mo, of the liver and the hepatic and pancreatic lymph nodes
Only when there are indications of a possible risk to human health, animal health or animal welfare
- Palpation of the liver and the hepatic and pancreatic lymph nodes (Lnn. portales); incision of the gastric surface of the liver and at the base of the caudate lobe to examine the bile ducts
Describe meat inspection in bovine >8mo, of the gastro-intestinal tract, the mesentery, the gastric and mesenteric lymph nodes
+ palpation of the gastric and mesenteric lymph nodes
When there are indications of a possible risk to human health, animal health or animal welfare: incision of the gastric and mesenteric lymph nodes
Describe meat inspection in bovine >8mo, of the udder and its lymph nodes
Only hen there are indications of a possible risk to human health, animal health or animal welfare
- A palpation and incision of the udder and its lymph nodes (Lnn. supramammarii) in cows.
- Each half of the udder shall be opened by a long, deep incision as far as the lactiferous sinuses (sinus lactiferes) and the lymph nodes of the udder shall be incised, except where the udder is excluded from
Instead of testing a pork carcass for Trichinella what can be done?
Freezing the carcass
Minimum core temp -18 when treated for 106 hours
Minimum core temp of -37 when treated for 30 mins
How does Trichinella spiralis infection occur?
Zoonotic:
- Infection by consumption of undercooked meat
- Life-threatening to mild symptoms in 5-20 days
- More noticeable when outbreak
Case: Epulides seen in the mouth
What action would be taken?
- Wont affect what happens to the carcass in this case
- But shows welfare implications -> farm serious breech
OV will declare meat unfit for human consumption if it derives from animals slaughtered under the age of …?
7 days
The meat fitness decisions are made based on which factors?
- Zoonotic infection if ingested?
- Zoonotic risk but not by consumption of presented product?
- Systemic process: Immunosuppression etc
No zoonotic risk but: - Prevention of animal disease spread (ex. FMD)
- Meat quality (ex. Traumatic lesions)
- Aesthetics (ex. Cysticercus ovis)
List some generalised conditions which are considered unfit for human consumption
Septicaemia
Pyaemia
Jaundice
Emaciation
Toxaemia
Viraemia
Malignant tumours
How can a carcass be tested for ‘fit for human consumption’ if it has toxaemia?
Hold carcase for 24 hours and check by boiling/frying test
Unfit for human consumption if smell still present
Name an example Viraemia that would be considered unfit for human consumption
BVD: Bovine pestivirus
- Sx: ulceration oesophagus, base of tongue and soft palate
- Disease: Bovine virus diarrhoea / mucosal disease
- Most common in young cattle (6-24 mo old)
When is neoplasia not fit for human consumption?
When its malignant
Melanosis discoloration is disposed of as?
Category 3 ABP
What is the most common malignancy in cattle?
Sporadic Bovine Lymphosarcoma
How does Sporadic Bovine Lymphosarcoma present?
The cause is not known
It occurs in young cattle between 6 months and 2 years of age
There are two forms :
- Multicentric = In which all the lymph nodes are massively enlarged and replaced by white homogenous tumour tissue
- Thymic lymphosarcoma = In which there is a large swelling in both the cardiac and cervical parts of the thymus
What happens to a carcass with sporadic bovine lymphoma?
Unfit for human consumption
Name a zoonotic condition of pigs where changes are seen due to necrosis/infarction
Erysipelothrix rhusiopathiae
How does the level of disease of Erysipelothrix rhusiopathiae influence the action taken on the carcass?
- Mild type - Diamonds visible on skin. Possible bacteraemia. Judgement: depending on lesions.
- Acute or septicaemic. Judgement: total rejection.
- Chronic: Arthritis, endocarditis, enlarged lymph nodes… Judgement: local or total rejection depending on severity and extension of the lesions.
If a pig carcass with Erysipelothrix rhusiopathiae has endocarditis, what action is taken?
Rejection of carcass due to emboli spread
What action is taken if a carcass has jaundice?
Unfit for human consumption
Yellow colour at the level of many tissues
What may also cause a yellow colouration of tissues?
Due to feed - this carcass would be normal
What action is taken if a carcass has septicaemia?
Unfit for human consumption
What is vertebral porphyria?
Porphyria is the accumulation of plant or endogenous porphyrins in the blood resulting in tissue pigmentation and photosensitization.
This is a hereditary disease and is observed in cattle, swine and sheep.
In porphyric cattle, exposure to light will initiate the development of photodynamic dermatitis. In swine, photodynamic dermatitis does not occur
What happens to a carcass with vertebral porphyria?
Partial rejection
If a carcass has anaemia what action is taken?
Diagnosis:
- White muscle disease – selenium/vitamin E deficiency
- Also linked to mulberry heart disease
Unfit for human consumption
What is Hydrocachexia?
Emaciation with serous atrophy of adipose tissue
DDX: Age related muscle atrophy
What action is taken if a carcass has Hydrocachexia?
Unfit for human consumption
What are the issues surrounding tail bites?
Welfare
Point of infection -> systemic spread of pathogens -> osteomyelitis
What action is taken in a carcass with rub fractures?
Decision - Callus – partial rejection because it shouldn’t have a major impact on the carcass
If no evidence of septicaemia
- Decision: Partial rejection
- Depending on extent/localization of callus could imply a welfare issue at the farm of origin
What action is taken in a carcass with calcification?
Partial rejection
DDx
- Abscess
- Contamination with foreign material
What action is taken in a carcass with embolic pneumonia?
total rejection
