The consumption of grapes and raisins presents a potential health threat to dogs. Their toxicity to dogs can cause the animal to develop acute kidney injury (the sudden development of kidney failure) with anuria (a lack of urine production). The phenomenon was first identified by the Animal Poison Control Center (APCC), run by the American Society for the Prevention of Cruelty to Animals (ASPCA). Approximately 140 cases were seen by the APCC in the one year from April 2003 to April 2004, with 50 developing symptoms and seven dying.[1]
It is not clear that the observed cases of kidney failure following ingestion are due to grapes only. Clinical findings suggest raisin and grape ingestion can be fatal, but the mechanism of toxicity is still considered unknown.[2]
The reason some dogs develop kidney failure following ingestion of grapes and raisins is not known.[3] Types of grapes involved include both seedless and seeded, store-bought and homegrown, and grape pressings from wineries.[4]Amycotoxin is suspected to be involved, but none has been found in grapes or raisins ingested by affected dogs.[5] The dose-response relationship has not been determined,[2] but one study estimated 3 g/kg or greater for grapes or raisins.[6] An April 2021 letter to the editor of JAVMA hypothesized that the tartaric acid in grapes could be the cause.[7]
The most common pathological finding is proximal renal tubularnecrosis.[8] In some cases, an accumulation of an unidentified golden-brown pigment was found within renal epithelial cells.[6]
Vomiting and diarrhea are often the first clinical signs of grape or raisin toxicity. They often develop within a few hours of ingestion. Pieces of grapes or raisins may be present in the vomitus or stool. Further symptoms include weakness, not eating, increased drinking, and abdominal pain. Acute kidney failure develops within 48 hours of ingestion.[5]Ablood test may reveal increases in blood urea nitrogen (BUN), creatinine, phosphorus, and calcium.
The prognosis is guarded in any dog developing symptoms of toxicosis. A negative prognosis has been associated with oliguria or anuria, weakness, difficulty walking, and severe hypercalcemia (increased blood calcium levels).[8]
^ abEubig P, Brady M, Gwaltney-Brant S, Khan S, Mazzaferro E, Morrow C (2005). "Acute renal failure in dogs after the ingestion of grapes or raisins: a retrospective evaluation of 43 dogs (1992–2002)". Journal of Veterinary Internal Medicine. 19 (5): 663–74. doi:10.1892/0891-6640(2005)19[663:ARFIDA]2.0.CO;2. PMID16231710.
^"News and Views". Veterinary Forum. 23 (1). Veterinary Learning Systems: 12. January 2006.
