Lecture Notes on Infectious Canine Hepatitis

Lecture Notes on Infectious Canine Hepatitis

1. Lecture Notes on Infectious Canine Hepatitis Dr Vidya Singh Senior Scientist Division of Pathology, ICAR-Indian Veterinary Research Institute Izatnagar, Bareilly, UP, India- 243122

2. Infectious Canine Hepatitis   Synonym : Rubarth disease, contagious hepatitis, Acute, febrile, highly contagious , of dogs & other canidae sps. Mild to high fever , MM congestion, tonsillitis, vomition , diarrhoea, Abominal pain, Ocular discharge, corneal opacity (hepatitis blue eye ), convulsion, severe leucopoenia , prolonged bleeding time   History : Rubarth (1947) in Sweden Etiology: Canine Adeno Virus-1, Adenoviridae , Genus mastadenovirus , DNA Virus, Risk Factors: CAV is stable and can stay on fomites upto 2 week , at 4 o C for 6-9 months   Epidemiology: Worldwide In India - endemic in all states  Host : Dogs, Fox, Wolf Young animals (upto 1 year) more susceptible Ferrets – Resistant  Source : Dogs, Fox (Reservoir) Virus excreted in urine, saliva and faeces Virus persists in kidneys, excrete virus in urine even after 1 yr of infection   Transmission: N o droplet transmission Ingestion of feed and water with urine/saliva/faeces

3. PATHOGENSIS ICP -2-10 days; Tropism - Epithelial, Reticuloendothelial and hepatic cells

4. Endothelium : Haemorrhages on meninges/SC/brain/thymus,/ heart/stomach , intestine, tonsils, all LNs, Bleeding in mouth Serosanguinous fluid in abdominal cavity, fibrin deposits on liver Liver: Haemorrhages, sinusoids dilated, pressure on liver parenchyma, degeneration of hepatocytes, centrilobular necrosis, I/N I/b in Kupffer/Hepatic cells . Infiltration of M, L, N in spaces of disse Enlarged , mottled, friable with fibrinous exudate GB : W all thickened due to edema Spleen : Haemorrhages, necrosis, enlarged, involution of follicles, I/N Inclusion body in endothelial and reticular cells Kidneys : Haemorrhages / necrosis in cortex, interstitium, Interstitial nephritis GIT : Haemorrhage in gastric mucosa, paint brush appearance Brain : Haemorrhages, Inclusion bodies Skin: Petichae , echymosis LNs: Congested , haemorrhages, swelling , enlarged, swelling of germinal centre Eyes : Inflammation of Iris & Ciliary body , I/b in cornea and iris endothelial cells

5. Hepatitis Blue Eye Mottled, Friable Liver

6. Clinical Signs: Per acute Form : High fever, severe leucopenia , conjuctivitis , haemorrhges , icteric , swollen tonsils, red buccal mucosa; sudden death in 12-24 hours Acute Form : High fever for 2 days, decline thereafter and again increase for upto 6 days ( Sadle Curve) Vomition /diarrhoea with blood , Anorexia and intense thirst; Bucal MM– Intense hyperemia , haemorrhagic, Abdominal tenderness , severe pain, tucked up abdomen Leukopenia Eyes: Corneal edema/ Inflammation of antr . uveal tract--- transient C orneal opacity, Hepatitis Blue Eye , Keratoconjuctivitis , Lacrymation , cloudiness of cornea , (Allergy reaction) S/C oedema of head, neck, abdomen   Nervous signs: Few cases, Seizures with barking, HL paralysis, clonic spasm of extremities and neck Pneumonia occurs in some pups (CAV-3 ), rapid respiration, coughing Recovery occurs in 2 weeks(70-80% dogs) Subclinical Form Most common form , Mild or subclinical signs- Fever, mild photophobia, enlarged tonsils, recovery

7. Diagnosis: Clinical Signs : Thin thready pulse with weak rapid heart sounds sudden fever, corneal opacity with prolonged clotting time HP : I/N Inclusion body in liver, GB, brain, cornea, etc. AGID, CFT, VNT Liver Function Test : Transminase level very high Animal Inoculation : in Ferret   DD Warfarrin poisoning : Prolonged clotting time, but no leukopenia, I/N inclusion body and abdominal pain Leptospirosis Tonsilitis CD