1. Julia Lankton, Natalie Durrett Crawford, Ondrej Becvar, Tanya LeRoith Virginia-Maryland Regional College of Veterinary Medicine Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

2.  Three week old Holstein heifer calf from large dairy  Abdominal distension Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

3.  Ataxia  Thiamine  Diarrhea  Sulfamethazine  Florfenicol  Electrolytes  Poor muscle tone Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

4.  Good appetite with little weight gain  Chemistry panel: Low BUN  EMG: WNL  Continued/Worsening ataxia  Rx corticosteroids – no improvement  Euthanized at 6 weeks Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

5.  Bacterial  TEME  Vertebral osteomyelitis  Viral  Rabies  Pseudorabies  Parasitic  Nervous coccidiosis  Parelaphostrongylus tenuis  Nutritional  Polioencephalomalacia  Vitamin A deficiency  Toxic  Lead toxicosis  Urea toxicosis  Congenital  Hydranencephaly  Hydrocephalus  Porto-systemic shunt?  Nah, that’s in small animals Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

6.  Body weight: 68 kg (150 lbs)  Normal: 82 kg (180 lbs)  Minimal fat stores  Small liver  Cerebral cyst Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

10.  Lobules small and irregular  Lymphatics and sinusoids dilated  Portal regions:  Small portal veins  Numerous portal arterioles Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

11. Liver H&E Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

12. Liver H&E Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

13. Liver H&E Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

14.  White matter vacuolization  Pronounced in white matter tracts bordering grey matter  Severity increases caudally  Scattered neuronal necrosis  1.4 mm diameter ependymal lined space  Rostral cerebral white matter Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

15. Cerebrum H&E Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

16. Cerebrum LFB-PAS Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

17. Brainstem H&E Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

18. Brainstem LFB-PAS Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

19. Spinal Cord H&E Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

20. Cerebrum H&E Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

21.  Morphologic :  Liver : arteriolar reduplication, lobular atrophy and lymphatic dilation  Brain : white matter, polymicrocavitation; focal syringoencephalocele  Disease : Portosystemic shunt with hepatic encephalopathy Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

22.  Rare in large animals (4 cases in calves)  Normal fetal communications patent  Portal blood bypasses liver and enters circulation  Decreased portal vein perfusion  Liver lobules atrophy  Portal veins are hypoplastic  Hepatic arterioles are hyperplastic Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

23.  Toxins from portal blood access CNS  Ammonia  astrocytes  decreased BBB  Ammonia, fatty acids, amino acids and other neurotoxins enter CNS  Astrocyte hypertrophy and degeneration  Alzheimer type II cells  More prominent in other spp.  Intramyelinic Edema  Diffuse bilaterally symmetrical polymicrocavitaton, predominantly of white matter and at grey-white border Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

25.  Dr. Natalie Durrett Crawford  Dr. Tanya LeRoith  Dr. Ondrej Becvar  Dr. Bernard Jortner  VMRCVM histopathology lab Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

26.  1.Buczinski, Sebastien, et. al. Portacaval shunt in a calf: Clinical, pathologic, and ultrasonographic findings. Can Vet J 2007; 48: 407-410.  2. Van Den Ingh, et. al. Congenital portosystemic shunts in three pigs and one calf. Vet Pathol 1990; 27: 56-58  3. Reimer JM, et. al. Diagnosis and surgical correction of a patent ductus venosus in a calf. JAVMA 1988; 193: 1539-1541. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only