Clinico-biochemical, ultrasonographic and pathological findings of hepatic abscess in feedlot cattle and buffaloes

Diagnostic utility of ultrasonography for thoracic and abdominal bacterial and parasitic diseases in ruminants: a comprehensive overview

This review article describes the roles of ultrasound in assessing thoracic and abdominal infectious diseases, mainly bacterial and parasitic ones that affect farm animals, including cattle, camels, sheep, and goats. Ultrasonography is a non-invasive imaging technique used to diagnose infectious diseases affecting the cardiovascular, respiratory, digestive, urinary, and hepatobiliary systems. In cases of thoracic and abdominal infections, ultrasound typically reveals abnormalities in echogenicity and echotexture, the presence of unusual artifacts, and mass formation exerting pressure on surrounding structures. Inflammatory and degenerative changes within the viscera can be identified ultrasonographically by comparing the echogenicity of affected areas with that of the surrounding normal parenchyma, such as in fascioliasis. Bacterial and parasitic infections often result in capsular mass lesions with anechoic contents, as observed in hydatid cysts and cysticercosis, or varying echogenic contents, as observed in liver abscesses. Effusions within the pericardium, pleura, and peritoneum are common ultrasonographic findings in infectious thoracic and abdominal diseases. However, these effusions' echogenicity does not always allow for clear differentiation between transudates and exudates. The routine use of ultrasonography in the evaluation of the chest and abdomen in affected or suspected ruminants is highly beneficial for detection, guiding therapeutic decisions, assessing prognosis, and aiding in the eradication of highly contagious diseases that cause significant economic losses.

Effects of supplemental zinc on growth, carcass characteristics, and liver abscess formation in steers with experimentally induced ruminal acidosis challenge

The study's aim was to evaluate the effect of dietary Zn supplementation on steer performance, biomarkers of inflammation and metabolism, and liver abscess formation in response to a mild acidosis challenge. Forty-two steers (417 ± 3.99 kg; n = 6/pen) were housed in pens with bunks designed to measure individual dry matter intake (DMI) and fed one of two diets containing either 0 (CON; n = 18) or 90 mg Zn/kg from a Zn-amino acid complex (Zn-AA; n = 18; AvailaZn; Zinpro) for 109 d. Six additional steers were fed the CON diet and did not undergo the acidosis challenge (NON; n = 6). The acidosis challenge included restricting steers to 50% of the previous 7 d daily DMI on days 46 and 47, steers were individually provided 10% of DMI as cracked corn (as-fed) at 0800 h followed by ad libitum feed access 2 h post-grain consumption. Steer was the experimental unit, and two contrasts were constructed: NON vs. CON and CON vs. Zn-AA. Blood samples were collected on days 40, 48, 53, 69, 80, and 108 and analyzed as repeated measures. Final body weight and overall average daily gain (2.29, 2.30, and 2.31 ± 0.920 kg/d for CON, Zn-AA, and NON, respectively) were not different (P ≥ 0.74) between treatments. By design, DMI was greater (P < 0.01) for NON compared to CON on day 46 but was not different (P ≥ 0.41) for the rest of the experiment. While hot carcass weight (423, 428, and 424 ± 7.9 kg for CON, Zn-AA, and NON, respectively) and ribeye area were not different (P ≥ 0.53) due to treatment, marbling score tended (P = 0.06) to be greater in CON compared to Zn-AA. The 12th rib backfat thickness was greater (P = 0.05) in NON vs. CON steers. Liver abscess incidence tended to be greater (P = 0.12) in CON (24% abscesses) vs. Zn-AA (6% abscesses). NON had a greater incidence (P = 0.05; 50% abscesses) compared to CON. Overall, blood fibrinogen and leukocyte counts were not different between treatments (P ≥ 0.67); however, neutrophil-to-lymphocyte ratio tended to be greater in NON vs. CON (P = 0.08). Serum aspartate aminotransferase and gamma-glutamyl transferase concentrations were greater in NON vs. CON (P ≤ 0.02), and serum alkaline phosphatase concentration was lesser in CON vs. Zn-AA (P < 0.01). Overall, dietary Zn supplementation tended to lessen incidence of liver abscesses with limited impacts on overall cattle performance. Shifts in liver enzymes may represent opportunities to identify cattle with liver abscesses earlier in the feeding period.

The effects of feeding benzoic acid and/or live active yeast (Saccharomyces cerevisiae) on beef cattle performance, feeding behavior, and carcass characteristics

Fifty-nine Angus-cross finishing steers were used to evaluate benzoic acid, active dry yeast (Saccharomyces cerevisiae), or a combination of benzoic acid and active dry yeast when supplemented in a high-grain finishing diet on live animal performance, feeding behavior, and carcass characteristics. Steers were fed a high-grain diet for the final 106 d of finishing. Treatments were as follows: no additional supplementation (CON), 0.5% benzoic acid (ACD), 3 g per head per day active dry S. cerevisiae (YST), or both 0.5% benzoic acid and 3 g/head per day S. cerevisiae (AY). Steers were weighed every 14 d, and ultrasound was performed for rib and rump fat thickness at the beginning (day 1), middle (day 57), and end (day 99) of the experiment. Insert feeding stations were used to collect individual feeding behavior data and DMI daily throughout. Blood samples were collected on days 21 and 22 and days 99-101 to assess plane of nutrition and metabolism. Ruminal fluid samples were collected by oral gavage 4 wk prior to slaughter. Carcass characteristics were examined at a federally inspected slaughter facility. Data were analyzed using PROC GLIMMIX of SAS with initial body weight (BW) as a covariate. Benzoic acid supplementation increased (P = 0.002) overall dry matter intake (DMI) compared to YST and CON steers, which may be due to a faster eating rate (P ≤ 0.008). Animal performance parameters (BW, average daily gain, feed conversion, and ultrasound fat depth) were not different (P ≥ 0.11) among treatment groups. Aspartate aminotransferase concentration was greatest (P ≤ 0.01) for YST steers, which may have been reflected in numerically greater liver abscesses. Carcass traits did not differ (P ≥ 0.33) among treatment groups. Ruminal pH was greater (P = 0.006) for ACD steers than AY steers (pH of 6.16 vs. 5.66, respectively), which indicated that there may be an interactive effect between benzoic acid and active dry yeast. To summarize, steers fed a high-grain finishing diet supplemented with benzoic acid, active dry yeast, or both benzoic acid and active dry yeast had similar growth performance and carcass characteristics compared to those without supplementation. However, the addition of benzoic acid alone increased DMI, variation in DMI, eating rate, and ruminal pH. Future studies are warranted to further investigate the impacts of benzoic acid on the ruminal environment of feedlot cattle.

Clinical and ultrasonographic investigations of 30 water buffaloes (Bubalus bubalis) with hepatomegaly

Background and Aim:

Knowledge of normal ultrasonographic dimensions of the liver and associated vascular structures is an important indicator for the diagnosis of hepatic diseases. Enlargement of the liver beyond its normal dimensions is the term of hepatomegaly and ultrasonography is the primary and the suitable diagnostic technique for this condition. Therefore, this study aimed to describe the clinical and ultrasonographic findings of liver diseases causing hepatomegaly in 30 buffaloes as well as to provide a range of liver dimensions and its blood vessel measurements in normal and diseased buffaloes.

Materials and Methods:

The study population included 30 buffaloes that were admitted to the clinic of the Faculty of Veterinary Medicine – Zagazig University for investigation of clinical signs associated with gastrointestinal diseases such as anorexia, chronic weight loss, and variable degrees of diarrhea or constipation. The animals were subjected to thorough clinical and ultrasonographic investigations. In addition, 10 healthy buffaloes were investigated ultrasonographically and post-slaughtering for comparison of liver dimensions and physical appearance.

Results:

Three conditions causing hepatomegaly were identified in this study as multiple focal hepatic lesions, diffuse fatty liver, and hepatic congestion. Clinically, it was difficult to differentiate between each condition while ultrasonography was the ideal tool for diagnosis after comparing with necropsy as a gold standard tool. Hepatomegaly was recorded in all affected animals with a significant decrease in the size of the portal vein (PV) and caudal vena cava (CVC) in animals affected with multiple focal hepatic lesions and fatty liver disease while the size of the PV and CVC was significantly increased in buffaloes with hepatic congestion.

Conclusion:

Ultrasonography can aid to accurately identify buffaloes with hepatomegaly and differentiate between different lesions involved.

Hepatobiliary diseases in buffalo (Bubalus bubalis): clinical, laboratory, and ultrasonographic findings

This study describes ultrasonographic observations of five hepatobiliary diseases in buffalo (Bubalus bubalis). Fifty buffalo, including 20 clinically normal and 30 hepatobiliary diseased buffalo were enrolled in the study. Complete clinical, radiographic and ultrasonographic examinations and laboratory analyses were conducted. Focal parenchymal lesions including liver abscess (n = 12) and hepatic cyst (n = 6), diffuse parenchymal lesion (hepatobiliary cirrhosis, n = 5) and obstruction of hepatobiliary passages including cholestasis (n = 4), and hepatocholelithiasis (n = 3) were successfully imaged by ultrasonography. Hepatic abscess imaged as a hypoechoic to echogenic circumscribed mass of various diameters with a distinct echogenic capsule. Hepatic cyst imaged as a pear-shaped sac with a bright echogenic margin, anechoic content, and distal acoustic enhancement. In hepatobiliary fibrosis, the liver showed linear bands of increasing echogenicity with less distinct imaging of the portal vasculature. Cholestasis was imaged as dilatation of the gallbladder (GB) with wall thickening and homogeneous or heterogeneous contents. Hepatocholelithiasis imaged as an echoic structure within the hepatic parenchyma, or within and around the GB and bile duct, with more echogenicity of the hepatic parenchyma than normal. Ultrasonography can be an efficient rapid, noninvasive tool for screening of common hepatobiliary diseases in buffalo under field conditions.