Carcass judgement of viral diseases in animals

Viral diseases of poultry

1. CARCASS JUDGEMENT VIRAL DISEASES

2. Acute pox viral disease of cattle manifested with sudden appearance of nodules on the skin. Lumpy Skin Disease

3. Insect vectors by direct and indirect transmission. Seasonal and geographic distribution. Transmission :

4. Incubation: 4 – 14 days Fluctuating fever Diarrhoea Nasal discharge and salivation The first lesion appear in the perineum Various sized cutaneous nodules (Fig .) may occur throughout the body Skin lesions may show scab formation Swelling of superficial lymph nodes and limbs, and lameness Infertility and abortion Secondary infection may lead to joint and tendon inflammation Antemortem Findings:

5. Lumpy skin disease. Various sized cutancous nodules in a severe case of lumpy skin disease.

6. Ulcerative lesions in the mucosa of the respiratory and digestive tract Reddish , haemorrhagic to whitish lesions in the lungs Edema (interlobular) and nodules in the lungs (Fig .) Heart lesion (endocardium) Thrombosis of skin vessels followed by cutaneous infarction and sloughing Postmortem Findings:

7. Cut surface of the nodules in the parenchyma of the lung and interlobular edema.

8. Allergies , screw-worm myiasis , urticaria , dermatophilosis ( streptothricosis ), bovine herpes dermophatic infection, cattle grubs, vesicular disease, bovine ephemeral fever, photosensitization, besnoitiosis (elephant skin disease), sweating weakness of calves, bovine farcy and skin form of sporadic bovine lymphomatosis Differential diagnosis : https://www.youtube.com/watch?v=MIPAKL35FuI

9. Carcass of an animal showing mild cutaneous lesions and no fever associated with general signs of infection is conditionally approved pending heat treatment. The affected parts of the carcass and organs are condemned. Carcass of an animal showing, on antemortem examination, generalized acute infection accompanied with fever, is condemned . Judgement :

10. IBR is a highly infectious viral respiratory disease of  cattle, goats  and  pigs  manifested by inflammation of respiratory passages and pustular lesions on the male and female genital organs. Generally four forms of the disease are recognized ; the respiratory form, the genital form, the enteric form and the encephalitic form. Infectious bovine rhinotracheitis (IBR)

11. Transmission : Respiratory droplet and nasal exudate in the respiratory form of IBR. Obstetrical operations, contact with genitalia of affected animals in the genital form of disease.

12. Respiratory form Incubation: 5 – 14 days Fever Nasal and ocular discharge and red, swollen conjunctiva Drop in milk yield Breathing through the mouth and salivation Hyperaemia of the nasal mucosa and necrotic areas on the nasal septum Secondary bronchopneumonia Abortion Antemortem findings:

13. Genital form Frequent urination and tail elevation Edematous swelling of the external genitalia and pustule formation on reddened vaginal mucosa Mucoid or mucopurulent exudate in the vagina Enteric form Severe oral and stomach necrosis in new born animals High mortality

14. The encephalitic form in calves Depression, Excitement, High mortality

15. Breathing through the mouth and salivation in a bovine affected with IBR.

16. Postmortem findings : Acute inflammation of the larynx, trachea and bronchi Profuse fibrino -purulent exudate in the upper respiratory tract in severe cases Chronic ulcerative gastro-enteritis in feedlot cattle Lung emphysema Secondary bronchopneumonia

17. IBR . Acute inflammation of the larynx and trachea

18. Judgement : Carcass of an animal affected with  IBR  is  approved  if signs of acute infection are not present and the animal is in good body condition. Differential diagnosis : Pneumonic pasteurellosis , bovine viral diarrhoea , malignant catarrhal fever and calf diphtheria

19. An infectious viral disease of cattle manifested by an active erosive stomatitis, gastroenteritis and diarrhoea . Bovine Viral Diarrhea (BVD)

20. Transmission : Direct contact with clinically sick or carrier animals, indirect contact with feedstuffs or fomites contaminated with urine, nasal and oral secretions or faeces and contact with aborted fetuses. Transmission through aerosol droplet dispersion or by insect vector may also be a possibility. Virus may persist in recovered and chronically ill cattle which are considered a potential source of infection.

21. Antemortem findings : Incubation: 1 – 3 days Fever Congestion and erosions in the mucous membranes of the oral cavity Depression and anorexia Cough, polypnea and salivation Dehydration and debilitation Foul-smelling diarrhoea

22. Cessation of rumination Reduced milk supply Abortion in pregnant cows Laminitis Congenital anomalies of the brain (cerebellar ataxia) and arthritis in young calves

23. Shallow erosions present on the entrance of the nostrils, mouth, pharynx, larynx, oesophagus , rumen (Fig .), omasum , abomasum ( Fig.), caecum and less frequently in Peyer's patches in the small intestine. Erythema of the mucosa with submucosal haemorrhage in the abomasum, small intestine, caecum and colon. Stripped appearance on the caecal and colon mucosa is similar to that seen in rinderpest . Cerebral hypoplasia and cataracts in calves Postmortem findings :

24. Congestion and erosions in the ruminal mucosa.

25. Inflammation of the abomasum ( abomasitis , gastritis).

26. Differential diagnosis : Malignant catarrhal fever, rinderpest , blue tongue and vesicular diseases (produce vesicles which are not present in BVD). Diseases with no oral lesion nor diarrhoea include salmonellosis, Johne's disease and parasitism

27. Carcass and viscera of an animal, which on antemortem examination showed generalized signs of acute infection accompanied with fever and/or emaciation, are condemned . Chronic cases of BVD with no systemic involvement have a favourable judgement of carcass, viscera and organs. Judgement

28. Coenurus cerebralis infection ( Gid , Sturdy ) Coenurosis is a disease of the brain and spinal cord caused by the intermediate stage of Taenia multiceps which inhabits the intestine of dogs, cats and wild carnivores. The clinical disease occurs in sheep and rarely in cattle. Judgement : Carcass affected with coenurosis is approved. Affected brain and organs are condemned.

29. Coenurus cerebralis . Thin walled cyst in the brain