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WSV18-0242
INFECTIOUS DISEASES AND GASTROENTEROLOGY (TRANSLATED INTO MANDARIN CHINESE)
PRACTICAL APPROACH TO ACUTE HEMORRHAGIC DIARRHEA SYNDROME IN DOGS
F. Gaschen1
1Louisiana State University School of Veterinary Medicine, Baton Rouge, LA USA
INTRODUCTION
Acute Hemorrhagic Diarrhea Syndrome (AHDS) is a new name proposed to describe the syndrome known for decades as Hemorrhagic Gastroenteritis (HGE). The new name defines the disease better since a studies out of Germany have demonstrated that affected dogs do not display any gastric inflammation. The syndrome can affect dogs of all breeds and all ages, although middle aged dogs of small and toy breeds seem to be predisposed.
ETIOLOGY
The etiology of AHDS is not known, although abundant Clostridium perfringens were shown to be present
in the duodenum of affected dogs. Other hypotheses about the etiology include dietary or microbial toxins, and severe dietary indiscretion. It is unclear if clostridial proliferation is a cause or a consequence of the disease. C. perfringens enterotoxins and C. difficile toxins A/B
do not appear to be involved in the pathogenesis. However, a newly discovered pore-forming cytotoxic toxin (NetF) produced by Type A C. perfringens has been co-localized with severe necrotic intestinal lesions in affected dogs. In addition, acute enteritis strongly impacts the intestinal microbiota, particularly with respect to species diversity, and causes acute dysbiosis.
CLINICAL PRESENTATION
Most affected dogs are small breed and middle-aged. A large German study reports a predisposition in Yorkshire terriers, miniature pinscher, miniature schnauzer, and Maltese, and a mean age of 5 years. Dogs with AHDS are typically presented with acute onset bloody diarrhea, possibly with vomiting and anorexia. They are usually very dehydrated and in various stages of hypovolemic and/or distributive shock. Lethargy and abdominal pain are also common.
DIAGNOSTIC APPROACH
Dogs with AHDS typically have a high PCV (often above 65%) and a normal or low serum concentration of total solids (or total proteins, albumin, or globulins). White blood cell counts may be normal, high or low depending on the severity of disease. Mild thrombocytopenia
is common. Other serum biochemistry changes may include pre-renal azotemia, increased liver enzymes, hypoglycemia, and electrolyte abnormalities. Metabolic
43RD WORLD SMALL ANIMAL VETERINARY ASSOCIATION CONGRESS AND 9TH FASAVA CONGRESS
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gas-filled or made out of mineral/metal. Cut-off fingers of plastic gloves filled with water and knotted tightly make excellent cystic targets to practice cystocentesis. Once the ultrasonographer is comfortable reliably reaching targets in a phantom and to always fully visualize the needle tip throughout the procedure, the move to a live patient is justified. Keeping in mind that it is much easier to see the needle in a phantom than in a real patient where heterogeneity of the subcutaneous fat partially obscures the needle signal in some cases. Easy targets should be chosen first such as cystocentesis, or fine needle aspirates of a large spleen or a large superficial mass that is not well perfused (check with Doppler ultrasound). The most challenging types of FNA should only be attempted when the ultrasonographer is very comfortable with needle guidance. Lymph nodes can be challenging as they are always closely associated with vascular structures. Additionally, they tend to move away from the needle as they are relatively loosely attached in the surrounding fat. Gallbladder aspirates carry the risk of bile peritonitis if leakage occurs after aspiration and to make things more difficult the gallbladder is located very cranially and affected by respiratory motion even
in sedated patients. Other higher risk aspirates include lung aspirates where there is a risk of pneumothorax, and aspirates of highly perfused lesions such as thyroid carcinomas. Finally, prior to performing fine needle aspirates a risk – benefit analysis should always be made keeping in mind possible complications and
the sensitivity and specificity of FNA in different organ systems.
References
1. Vet Radiol Ultrasound. 2013; 54(6): 638-645.
2. Vet Radiol Ultrasound. 1993; 34(6): 438-444.










































































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