Signalment: 9-year-old male neutered domestic shorthair cat
History: Presented to the Emergency Service as a transfer from his primary veterinarian for further evaluation of abdominal distention. The patient’s abdomen had become distended over the past several days. He was still acting normally with no vomiting, diarrhea, or change in appetite or labored breathing. He is indoors only. He was adopted as a kitten, only animal in the household, no travel history, and up to date on vaccinations.
Physical Exam Findings: Markedly distended, tense, abdomen with palpable fluid wave. Remainder of exam within normal limits.
Initial treatments: Abdominocentesis was preformed and 1325mls of milky white fluid was removed without complication.
Diagnostic Evaluation: A CBC performed at RDVM prior to referral showed neutropenia (0.07 k/ul, RR: 2.5-15 k/ul) and thrombocytopenia (clumping?), chemistry was normal with a low normal albumin (2.6, RR: 2.3-3.9 g/dl). Thoracic radiographs were normal. He was Felv/FIV neg. Abdominal Ultrasound showed a moderate volume of echogenic effusion. The mesentery and omentum were thickened and hyperechoic. Echocardiogram showed no cardiac disease. Abdominal Fluid analysis was consistent with chylous effusion, nucleated cells were predominantly small mature lymphocytes, with triglycerides >3200 and TP 6.1.
Assessment: Possible causes for chyloabdomen included neoplasia such as lymphosarcoma or other cancer, lymphangiectasia, FIP, or cardiac disease, but the later had been excluded based on normal echocardiogram and FIP was considered less likely given age and lack of exposure.
Plan: He was started on Rutin (250 mg PO q8 hours) with a plan to follow up with internal medicine.
Follow-up exam with Internal Medicine: Since discharge from the ER, the patient’s appetite had been slightly decreased since starting the Rutin and it was decreased to twice daily. Otherwise doing well.
On recheck exam, the patient had a palpable abdominal fluid wave and had muscle wasting along his spine. He had gained weight (0.4 kg since discharge). A brief ultrasound showed a moderate amount of echogenic effusion, no pleural effusion was noted. There was not enough peritoneal effusion to do an abdominocentesis. An FIP PCR on the abdominal effusion was discussed. An abdominal exploratory was recommended for a more definitive diagnosis.
Abdominal Exploratory Findings: The omentum was very friable. The mesentery was diffusely friable and dark in color. A dark red mass was noted at the ileocolic junction. There were numerous small nodules on the surface of the intestines, the majority on the jejunum but also present on the deudenum, ileum, and large intestines. There was peritoneal effusion in the abdominal cavity. The right lobes of the liver contained a large amount of what appeared to be fibrin and the lobes were rounded.
The surgical findings were discussed with the owners. They opted for humane euthanasia due to concern for quality of life, and amount and severity of widespread disease on exploratory.
Histopathology findings: The ileocecocolic mass, jejunal and liver biopsy were submitted for histopathology.
Moderately differentiated serosal hemangiosarcoma, intestines; Mild lymphoplasmocytic portal hepatitis.
Chylous effusion are predominantly composed of chyle, the lymphatic fluid that flows thru the lacteals of the small intestines and the thoracic duct. The effusion has a characteristic milky white appearance. Underlying causes for chylous effusion include cardiac disease, mediastinal masses, heartworm disease, trauma, granulomas, congenital thorax duct abnormality, biliary cirrhosis, Vitamin E deficiency and diffuse lymphatic disease such as lymphangiectasia or lymphosarcoma (Borku et. Al 2005). Unlike chylothorax, chyloabdomen is uncommon in cats. There are various causes of chylous abdominal effusion in cats such as trauma, lymphoma, chronic pancreatitis, feline infectious peritonitis (FIP), cancer. In one study, seven out of nine cats with chyloabdominal had intra-abdominal neoplasia. Hemangiosarcoma (3 cats), paraganglioma (1 cat) lymphoma (2 cats, small intestinal), lymphangiosarcoma (1 cat, abdominal wall). Unfortunately, four of the cats had unresectable tumors. Survival times varied depending on location and type of neoplasia ranging from euthanasia at the time of surgery, 5 cats were euthanized within 3 months of surgery, one cat with lymphoma lived for 14 months after surgery and also received chemotherapy. Of the two cats with non-neoplastic disease, one had severe biliary cirrhosis and the other had vitamin E deficiency (Gores BR et al 1994). There have also been several case reports of cats with chylous abdominal effusion with FIP, one cat had chylous effusion in the thorax and abdomen (Boreu et al 2005).
Hemangiosarcoma (HSA) in cats is also uncommon and accounts for less than 2% (visceral and non-visceral HSA) of feline malignancy. The frequency of feline visceral HSA was estimated to be 0.04%. HSA typically has a poor to guarded prognosis since it is highly metastatic. One study, reports 77% of cats had multifocal disease at the time of diagnosis (Culp et al. 2008). Chemotherapy with doxorubicin and vincristine have been used in select cases.
Submitted by: Sarah Muhrer, DVM
1. Borku MK, Ural K, Karakurum MC, et al: Chylous pleural and peritoneal effusion in a cat with feline immunodeficiency virus; diagnosis by lipoprotein electrophoresis. Revue Med.Vet 12: 612-614, 2005.http://www.revmedvet.com/2005/RMV156_612_614.pdf2.x/full
2. Culp WN, Drobatz KJ, Glassman, MM et al: Feline visceral hemangiosarcom: Journal of Veterinary Internal Medicine 22: 148-152, 2008 http://onlinelibrary.wiley.com/doi/10.1111/j.1939-1676.2008.002
3. Gores BR, Berg J, Carpenter JL et al:Chylous ascites in cats: nine cases (1978-1993): Journal of the American Veterinary Medical Association 8: 1161-1164, 1994. https://www.researchgate.net/publication/15307805_Chylous_ascites_in_cats_Nine_cases_1978-1993
4. Savary KC, Sellon RK, and Law JM: Chylous abdominal effusion in a cat with feline infectious peritonitis. Journal of the American Animal Hospital Association 37: 35-40, 2001. www.jaaha.org/doi/pdf/10.5326/15473317-37-1-35