Protein losing enteropathy in a dog

25 Protein losing enteropathy in a dog




Initial presentation


Diarrhoea and weight loss


Signalment: 9-year-old neutered male Jack Russell terrier, body weight 5.3 kg



Case history


The dog presented with a 3-month history of diarrhoea, which had initially been intermittent, but had become more persistent during the previous month. The faeces were described as soft to watery, containing no blood or mucus. He produced large volumes two to four times a day. He did not strain to defecate. He had lost about 0.5 kg during the previous month. He rarely vomited, but his appetite had decreased. His exercise tolerance was decreased and the owners thought he had become a bit quieter and less active in the house.


He had previously been a healthy dog and was fully vaccinated yearly. He had been treated for internal parasites with a commercial product (unknown type) about 4 months prior to consultation. His usual diet was a commercial dry dog food and during the month prior to his consultation the owners had been adding canned tuna and other foods to encourage him to eat.



Physical examination


On physical examination the dog was quiet but alert and responsive. His body condition score was 4/9, with evidence of recent weight loss.


His mucous membranes were pink with a capillary refill time of <2 seconds and his hydration appeared adequate. His abdomen was slightly distended and had a fluid thrill. On abdominal palpation, the intestines felt thickened and ‘ropey’. Thoracic auscultation and percussion revealed dullness in the ventral thorax and muffled heart sounds. His heart rate was 106 beats per minute. Peripheral pulse quality was adequate and pulses were matched with the heart rate. The respiratory rate was moderately elevated at 48 breaths per minute, with an increased inspiratory effort. Rectal temperature was 37.9° C and soft faeces were present on the thermometer.



Problem list and discussion of problems


The dog’s primary problem was diarrhoea, which was thought to be small intestinal in origin due to the presence of weight loss, the lack of blood or mucus in the faeces and to the lack of tenesmus during defecation. There was an increase in frequency of defecation, which is commonly seen in diarrhoea of large intestinal origin, but can also be seen when the storage capacity of the colon is overwhelmed by the volume of faeces. Another problem was the apparent presence of fluid in the abdomen.



Differential diagnosis


Differential lists for the diarrhoea (small intestinal):


• Dietary
• gluttony – unlikely as the dog’s appetite was decreased rather than excessive

• changes of diet – possible with a variety of food being fed; however, the diarrhoea started prior to the variations in diet

• adverse reaction to food: intolerance or allergy

• Gastric disorders
• rapid gastric emptying

• Small intestinal disease
• infectious (e.g. bacteria, virus, fungus)

• gastrointestinal parasites

• infiltrative neoplasia (e.g. lymphoma, mastocytosis)

• partial obstruction (e.g. intussusception, foreign body)

• lymphangiectasia

• brush border defects

• inflammatory bowel disease (IBD)

• Pancreatic disease
• chronic pancreatitis

• exocrine pancreatic insufficiency

• pancreatic neoplasia

• Liver disease
• bile duct obstruction

• liver failure

• Kidney disease – unlikely as he did not have polyuria/polydipsia (pu/pd), although glomerular disorders may present without pu/pd

• Miscellaneous
• congestive heart failure – no other signs consistent with this

• immunodeficiencies (e.g. IgA deficiency)

• hypoadrenocorticism

Another problem in this case was the increased fluid palpated in the abdomen (and suspected in the thorax). Differential diagnoses for ascites rely on first determining the type of fluid:


• Transudate

• Modified transudate

• Exudate

• Chyle

• Pseudochyle

• Blood


Case work-up



Minimum data base


Routine haematology revealed a moderate leucocytosis with a total WBC count of 23 × 109/l (reference range 6.0–15.0 × 109/l), due predominantly to a mature neutrophilia of 20 × 109/l (reference range 3.6–12.0 × 109/l). Lymphopenia was present with a lymphocyte count of 0.46 × 109/l (reference range 0.7–4.8 × 109/l).


Serum chemistry results showed panhypoproteinaemia with a total serum protein concentration of 28 g/l (reference range 58–75 g/l), due to a decreased albumin concentration of 13.7 g/l (reference range 26–35 g/l) and decreased globulin concentration of 15.3 g/l (reference range 18–37 g/l). Total serum calcium concentration was decreased to 2.0 mmol/l (reference range 2.3–3.0 mmol/l), likely due to the decrease in the albumin bound fraction of calcium.



Clinical tip on hypocalcaemia with hypoalbuminaemia


Normally about 40% of the total serum calcium is bound to albumin, with about 10% chelated to anions and about 50% ionized and unbound. The ionized fraction is the biologically active fraction. With decreased albumin, the bound fraction is decreased, but the ionized fraction is often within the reference range and therefore clinical signs of hypocalcaemia are usually not seen. Ionized calcium can be measured to ensure that it is within the reference range.


The total calcium can also be ‘corrected’ for hypoalbuminaemia and while the accuracy of this calculation is questionable, it is useful as an estimation. The SI units must first be converted to conventional units, e.g. for this case:



image



To convert this back to SI units, divide by 4, e.g. 10.13/4 = 2.54 mmol/l, which is within the reference range.


Serum cholesterol concentration was decreased to 1.7 mmol/l (reference range 3.8–7.0 mmol/l). Serum liver enzyme concentrations were moderately increased, with an alkaline phosphatase of 242 IU/l (reference range 20–60 IU/l) and ALT of 174 IU/l (reference range 21–102 IU/l).


Serum cobalamin concentration was decreased at 112 ng/l (reference range 215–908 ng/l) as was serum folate at 4.5 µg/l (reference range 7.7–24.4 µg/l).


Urinalysis results were unremarkable, with a urine specific gravity of 1.040. Urine protein to creatinine ratio was 0.05 (reference range <0.5).


Faecal analysis was negative for parasites and also negative on culture for enteropathogenic bacteria.



Imaging


Abdominal ultrasound revealed changes (speckling and increased thickness) in the small intestinal mucosa, consistent with lymphangiectasia and a protein losing enteropathy. Free fluid was noted within the pleural and peritoneal spaces. Thoracocentesis was performed and 340 ml of a clear fluid was removed from the pleural space. Analysis of this was consistent with a pure transudate.



Clinical tip on fluid analysis


The type of fluid present in an effusion gives an indication of the source. Modified transudates, transudates and exudates are distinguished by the specific gravity, total protein, number of nucleated cells, the cell type and the presence of bacteria (see Table 25.1).



Table 25.1 Determination of the type of fluid present in an effusion

image

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Sep 22, 2016 | Posted by in SMALL ANIMAL | Comments Off on Protein losing enteropathy in a dog

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