What if your pup vomits after weaning?

Food intolerance
Food intolerance is a non-immunologic, abnormal physiologic response to a food or food additive (Ettinger 6^th ed). Food intolerance is similar to food allergy except that it can occur with the first exposure to a food or food additive, because non immunologic additives are involved.

Another cause of food intolerance is pharmacologic reactions to substances found in food. Vasoactive or biogenic amines such as histamine cause clinical signs when present in excessive amounts in food.

The exact mechanism of food intolerance has not been depicted in dogs. Intolerance to solid food commonly occur secondary to rapid food changes. Loss of gastric mucosal enzyme activity contributes to vomiting and associated enteritis. Inadequate gastric enzymes are another factor contributing to vomiting subsequent to rapid food changes. More time is required for gastric enzyme activity to get adapted to changes in food carbohydrate and protein sources. Sudden or rapid dietary changes could also lead to diarrhoea , flatulence or abdominal discomfort depending on the type of food ingested and the level of abnormal physiologic response in the animal.

A CLINICAL CASE REPORT ON CANINE FOOD INTOLERANCE

Case presentation

PUPPY, a 1 month year old male Doberman pinscher weighing 900g was presented to the Veterinary Teaching Hospital on 15^th May 2018, with the complaint of vomiting and reduced appetite since one day. History suggested that the dog had been fed with an excessive amount of commercial dog food (“Pedigree”) two days back and that the clinical signs occurred ever since then. The pup had been treated with ondansetron 4mg tablets but vomiting had not subsided. On the next day, 16^th  May 2018 the puppy was presented back with the complaint of vomiting thrice that day morning. The patient had a deworming history on the previous day with ¼ tab of pyrantin. The pup had had a loss of appetite and water intake, normal urination and normal defecation. The patient was not vaccinated and was not in association with any other adult dogs except its own dam. 

At presentation PUPPY was Bright, Alert and Responsive (BAR). General Clinical Examination revealed a mild dehydration (7%) and yellowish frothy vomitus.

Differential Diagnosis

According to the GCE findings and history the differential diagnosis were

1.      Food intolerance

2.      Gastritis

3.      Gastroenteritis

4.      Pancreatitis

Food intolerance was the first diagnosis since the patient had a history of excessive commercial dog food introduction for the first time and thereafter vomiting. Gastritis was taken as the second differential diagnosis as the pup had frothy vomiting and loss of appetite. Gastritis was taken as the second differential diagnosis as the pup had frothy vomiting and loss of appetite for more than a day. The third differential diagnosis was gastroenteritis because the pup was not vaccinated against any disease. Pancreatitis was the last differential diagnosis due to several episodes of vomiting.

Laboratory and other investigations

To approach a diagnosis a blood smear analysis, a faecal smear analysis and a faecal wet mount analysis was performed.

The blood smear revealed normochromic normocytic erythrocytes and normal levels of leucocytes indicating absence of ongoing eosinophilic enteritis. The blood smear was also negative for haemoparasites. The faecal smear was negative for leucocyte infiltration and the faecal wet mount was negative for any worm infestation. At this stage pancreatitis, gastroenteritis and gastritis were ruled out and the condition was diagnosed as food intolerance.

Treatment and management

PUPPY was managed as an outpatient and treated with Normal Saline IV infusion, Dextrose 10% IV infusion (fluid requirement annexed) and promethazine (0.2 mg/kg) IV injection at the OPD. The prescribed drugs include Amoxicillin (20mg/kg PO q12h) as an antibiotic to overcome the ongoing bacterial infection if any, Promethazine (0.2mg/kg PO q24h) as an anti-emetic to stop vomiting and “Gastryl” Syrup (2ml PO q12h) to overcome the flatulence caused by food intolerance.

Prognosis

Upon following up of the case on the next day it suggested that PUPPY’s condition was improved and that vomiting had ceased.

Discussion

Food intolerance and food hypersensitivity are two terms that are often misused. On a practice level, these two terms are frequently interchanged because the precise immunologic processes of most adverse reactions are usually not known. The only way to diagnose food intolerance is by the rule of exclusion of all other possible differential diagnosis and by history taking. A sudden dietary change especially to a puppy does not withstand its stomach and therefore it is important to do gradually introduce food allowing time for adaptation.

 Pediatric canine patient treatment protocols need high considerations since their renal therapeutic function is immature until around six weeks, slower gastrointestinal transit time, increased gastric pH and more permeable blood brain barrier when compared with adult canine patients. Beta lactams are the safest antibiotics that could be used on pediatric patients.

Amoxicillin is a broad spectrum antibiotic which binds to penicillin-binding proteins involved in bacterial protein synthesis thereby decreasing cell wall strength and rigidity, affecting cell division, growth and septum formation. Promethazine is an anti-emetic that binds to H1 histamine receptors and prevents histamine from binding. “Gastryl” syrup is an appetizer, digestive, anti-flatulent and anti-spasmodic.

The animal fully recovered with the treatment with no signs of vomiting.

Reference

·         Ettinger S.J Feldman E.C Text Book of Veterinary Internal Medicine (2005) 6^th ed.

·         Saunders Manual of Small Animal Practice 3^rd ed.

 Annex

Fluid Requirement:

Normal Saline = 77 ml , D10% = 194 ml