Hyperammonemia Case in an Iceland Pony

Year 2018, Volume: 15 Issue: 2, 197 - 201, 15.08.2018

Ali Cesur Onmaz

Abstract

A 22 years old castrated male Iceland pony was presented at the Clinic of Vienna Veterinary University due to vague colic symptoms. The blood examination indeed revealed hyperammonemia (Ammonia: 136 μmol/L, normal value for healthy horses: <20 μmol/L). The patient received intravenous fluids aimed at flushing out toxic metabolites. Furthermore, lactulose was given per nasogastric tube. After this therapy, there was short-term improvement for some hours, but the animals again developed serious odd behavior. He was very ataxic and injured itself. Based on the bad prognosis, the owner took the decision to have the mare euthanized. Necropsy revealed cachexia, severe ascites; the liver seemed smaller, felt dense and had an irregular surface. Histopathology showed fibrotic degeneration and necro-sis of the hepacytes, a generalized accumulation of fat, medium degree of edema and in all liver lobes. The diagnosis confirmed hepatocites encephalopathy caused by hepatic cirrhosis.

Keywords

Colic, horse, hyperammonemia

References

• 1. Bachmann C. Mechanisms of hyperammonemia. Clin Chem Lab Med 2002; 40(7): 653-62. 2. Chan H, Butterworth RF. Cell-selective effects of ammonia on glutamate transporter and receptor function in the mammalian brain. Neurochem Internat 2003; 43(4-5): 525-32. 3. Desrochers AM, Dallap BL,Wilkins PA. Clostridium sordelli infection as a suspected cause of transient hyperammonemia in an adult horse. J Vet Intern Med 2003; 17(2): 238-41. 4. Dunkel B, Chaney KP, Dallap-Schaer BL, Pellegrini-Masini A, Mair TS,Boston R. Putative intestinal hyperammonemia in horses: 36 cases. Equine Vet J 2011; 43(2): 133-40. 5. Hasel KM, Summers BA, Delahunta A. Encephalopathy with idiopathic hyperammonaemia and Alzheimer type II astrocytes in Equidae. Eq Vet J 1999; 31(6): 478-82. 6. Hintz HF, Lowe JE, Cliffor AJ, Visek WJ. Ammonia intoxication resulting from urea ingestion by ponies. J Am Vet Med Assoc 1970; 157(7): 963-6. 7. Hughes KJ, Mcgorum BC, Love S, Dixon PM. Bilateral laryngeal paralysis associated with hepatic dysfunction and hepatic encephalopathy in six ponies and four horses. Vet Rec 2009; 164(5): 142-7. 8. Mair TS, Jones RD. Acute encephalopathy and hyperammonemia in a horse without evidence of liver disease. Vet Rec 1995; 137: 642-3. 9. Mcconnico RS, Duckett WM, Wood PA. Persistent hyperammonemia in two related Morgan weanlings. J Vet Intern Med 1997; 11(4): 264-6. 10. Mcgorum BC, Murphy D, Love S, Milne EM. Clinicopathological features of equine primary hepatic disease: A review of 50 cases. Vet Rec 1999; 145(5): 134-9. 11. Peek SF, Divers TJ, Jackson CJ. Hyperammonemia associated with encephalopathy and abdominal pain without evidence of liver disease in four mature horses. Eq Vet J 1997; 29(1): 70-4. 12. West HJ. Clinical and pathological studies in horses with hepatic disease. Equine Vet J 1996; 28(2):146-56.