Vomiting and Diarrhoea

Benji has a 7 day history of diarrhoea – what questions do we have for the owner?

Vomiting in addition to diarrhoea helps guide management, rather than our differentials.

Vomiting can be a useful indicator of a complete or partial obstruction (think foreign body, intussusception, tumour such as adenocarcinoma or lymphoma) but otherwise vomiting and diarrhoea are both seen with GI and non GI disease (liver, pancreas, renal, hypoadrenocorticism).

Most importantly, remember vomiting is seen frequently with intestinal disease.

What about if other pets are affected? What does this information help to rule in or rule out?


After questioning, the owner reveals Benji has soft/watery yellow diarrhoea, his appetite is still good and he is bright and well in himself. He has vomited yellow bilious fluid twice. There is no change in his drinking and no weight loss has been noticed. No other pets are unwell. The grandchildren visited last week and he may have had some more treats than usual …


Remember that a tense abdomen in a fat dog will be difficult! Rectal exam is more helpful in LI disease but can be used to assess faeces, as well as LNs and rectal wall.

More infomation!

The abdomen is not painful and SIs feel gassy or fluidy. There are no obvious mass lesions and the rectal exam is normal.

So the history and physical exam suggest a dietary intolerance. Acute gastroenteritis is often self limiting and further investigations are difficult to justify at this point.

Giardia is a differential at this stage but unlikely because he is not juvenile. Treating this self limiting disease may be misinterpreted as a response to treatment.

Should we starve Benji and, if so, for how long? If not, why not? When should we feed him and what should be advise?

Feed small, frequent, low fat (promotes stomach emptying), bland and easy to digest meals, such as rice/pasta and lean meat or eggs. We should feed this diet until the diarrhoea resolves and then gradually reintroduce normal food. This is not suitable for a long term (weeks to months) diet.

If everything goes well, a follow up appointment might be considered a “waste of money” by Benji’s owner. But we should see Benji if the vomiting deteriorates, he goes off his food or seems unwell or the diarrhoea persists or changes.

We would usually expect his stools to be much improved within 5-10 days (often much sooner) for a simple gastroenteritis. So… we don’t need to see them all back but we do need to make the owners aware of their responsibility to come back if in any doubt.

Benji returns 6 weeks later …

Benji has vomited 3-4 times since we last saw him He is less keen to eat, polydipsic and lethargic, especially over the last 10 days. His owner is still worried about the diarrhoea …

Benji was also weighed in the waiting room before your consult and has gained weight, from 11.5kg to 12.3kg. What could account for his weight gain?


Benji is quiet but alert and responsive. His abdomen is tense and distended with a palpable fluid thrill and organs are not palpable.

HR 112bpm, T 38.5, MM pink and slightly tacky with CRT 1-2s. His murmur is unchanged but he has a mild tachypnoea (RR 36bpm) with shallow breathing.


Sometimes we need to be cautious with IVFT, even if our patient is dehydrated.

In a hypoalbuminaemic patient, IVFT could worsen ascites +/or pleural effusion.

In a patient with heart disease, IVFT could cause or worsen pulmonary oedema- cats love to do this!

If in doubt we should at least give maintenance fluids for a while after collecting blood/urine samples.

What would you like to do for Benji next, and why? We need a plan and be able to explain it to Benji's owner.

Time for some tests then!


Radiography is not likely to be helpful when we already know we have a very ascitic abdomen but ultrasound can help.

As a general rule:radiography loves fat and hates fluid, ultrasound loves fluid and hates fat.

BUT if we are worried about pleural fluid then thoracic radiographs will help us rule that in or out.

Very mild elevation of ALT is likely secondary to GI disease, rather than indicating a primary liver disease. The low total Ca reflects hypoproteinamia (as Ca is bound to albumin in blood) – if in doubt, check iCa. Hypoproteinaemia reduces plasma oncotic pressure so fluid leaks into potential spaces.

Do we need need to be worried about Benji's tachypnoea?

What are the major differential diagnoses for Benji's PLE?

So, let's do some diagnostic imaging.

What treatment can we offer Benji? What is the prognosis?


Treatment Plan

Rule out parasites: treatment trial (fenbendazole) or faecal analysis

Consider antibiotic treatment trial for ARD if bacterial flora deranged due to leakageof fat/lymph in to lumen +/or malabsorption. Sometimes we use metronidazole-might have immunomodulatory properties.

Fat restricted diet +/- rule out diet intolerance as cause of inflammation- single source protein or hydrolysed protein exclusion diet

Anti inflammatory/immune suppressive treatment: prednisolone likely to be the first line treatment. Might need to consider other drugs such as cyclosporine if inadequate response to treatment

Diuretics?-often not needed but spironolactone seems to be more effective at managingascites than frusemide. Would consider if ascites was causing discomfort-potential to have an adverse effect on GI blood flow due to increased abdominal pressure.

Supplement cobalamin if low- worth checking serum cobalamin this in any chronic GI case


Ascites can resolve very quickly if the albumin improves in to the high teens or higher. We want Benji to lose fluid (one of the few times we want weight loss from a diarrhoea dog!) Polydipsia should resolve as ascites resolves. He will become polyuric when he shifts fluid from the abdomen.

PU/PD is hard to interpret once dogs are on prednisolone.

We can also check PCV/TS as a cheap monitoring tool rather than running biochemistry each time.


The prognosis can be guarded, although Yorkies seem to have a very steroid responsive form of PLE.

Benji did well on prednisolone and an exclusion diet. He had cobalamin supplementation but no diuretics.

He stayed on the diet long term but also had recurrent signs when he stopped prednisolone so stayed on these on a relatively low anti inflammatory dose.