Topic:Blood Ammonia Levels
Blood ammonia levels in horses refer to the concentration of ammonia present in the bloodstream, which can be an indicator of liver function and metabolic status. Ammonia is a byproduct of protein metabolism and is typically converted to urea in the liver for excretion. Elevated blood ammonia levels may suggest liver dysfunction or other metabolic disturbances. Monitoring these levels can aid in the assessment of liver health and the diagnosis of conditions such as hepatic encephalopathy. This page compiles peer-reviewed research studies and scholarly articles that explore the measurement, regulation, and clinical implications of blood ammonia levels in equine health.
Computed tomography angiography of a congenital extrahepatic splenocaval shunt in a foal. Congenital portosystemic shunts in foals are rare and only a small number of cases have been described. Detailed description of the course of the shunt is lacking in earlier reports. This is the first detailed description of a computed tomography angiography (CTA) displaying an extra-hepatic splenocaval shunt. A 1-month old colt showing increasing signs of dullness, ataxia, circling, lip-smacking and coordination problems was presented. Hyperammonemia was detected and abdominal CTA revealed an extra-hepatic portocaval shunt. During surgery, ligation of the abnormal vessel could not be achieved...
Bilateral laryngeal paralysis associated with hepatic dysfunction and hepatic encephalopathy in six ponies and four horses. Six ponies and four horses with a mean (sd) age of 15.9 (6.0) years developed sudden-onset bilateral laryngeal paralysis (BLP) in association with hepatic dysfunction. Nine of them had been referred for the investigation of respiratory distress, and one pony had been referred for weight loss before BLP developed. Nine of the animals had clinicopathological evidence of liver disease, and nine had histological evidence of liver disease. All of the animals had one or more of the following: hepatic encephalopathy (in eight), hyperammonaemia (in six) and endoscopic evidence of BLP (in nine). Three ...
Diarrhea and hyperammonemia in a horse with progressive neurologic signs. A 2-year-old, Quarter Horse filly was referred to Michigan State University, Veterinary Teaching Hospital with a 2-3 day history of depression and partial anorexia progressing to severe, watery diarrhea with severe neurologic abnormalities, including repetitive muscle fasciculations, muscle stiffening, and collapse. Laboratory findings included severe polycythemia, neutropenia, metabolic acidosis, and electrolyte and fluid loss, consistent with watery diarrhea and endotoxic shock. Increased creatine kinase and aspartate transaminase activities were consistent with recent transport and the musc...
Neurologic signs and hyperammonemia in a horse with colic. A 23-year-old Thoroughbred gelding was referred for the evaluation of acute onset of ataxia and depression, and a 2-day history of fever. On physical examination, the gelding was profoundly depressed and 10-12% dehydrated. The horse appeared very unstable, with a wide-based stance in the hind limbs, severe symmetric ataxia in all 4 limbs, and proprioceptive deficits in both hind limbs. Nasogastric intubation produced 4 L of brown, fetid reflux, and rectal examination revealed mild small intestinal and cecal distention. Hematologic abnormalities included neutropenia with toxic change, compatibl...
Encephalopathy with idiopathic hyperammonaemia and Alzheimer type II astrocytes in equidae. In 3 mature female horses of varying breeds, episodes of colic and depression for 14 days preceded an encephalopathic disorder with maniacal behaviour, anxiety, profuse sweating and, in one case, terminal opisthotonus. Blood ammonia levels were elevated approximately 10-fold. At necropsy, there were gastrointestinal serosal and mesenteric haemorrhages. Histologically, all 3 cases revealed diffuse Alzheimer type II astrocytes in the cerebral grey matter. Alzheimer type II astrocytes were glial fibrillary acidic protein (GFAP) negative or only weakly positive, weakly S-100 positive, and vimentin...
Persistent hyperammonemia in two related Morgan weanlings. Persistent hyperammonemia was diagnosed in 2 Morgan fillies with clinical signs that developed early in the postweaning period. Diagnostic evaluation, including routine serum chemistries, CBC, liver biopsy, hepatic ultrasonography, liver function test, and necropsy findings did not support a toxic, developmental, or infectious cause. Abnormal serum amino acid and urine orotic acid concentrations suggest that the foals may have had an inherited disorders described in humans as hyperornithinemia, hyperammonemia, and homocitrullinuria (HHH) syndrome. The disorder is thought to be caused by a defe...