Eight more varieties of canned dog food are being recalled for potentially toxic levels of vitamin D, Hill's Pet Nutrition announced Wednesday.
The company voluntarily recalled 25 products for the same concern earlier this year. The number of dog food affected now totals 33. Varieties of the company's canned Prescription Diet and Science Diet foods, sold and recommended at a variety of veterinarian offices across the nation, were affected.
In a letter to veterinarians, Hill's said a review of its products determined the issue was isolated to a vitamin premix used in its canned dog foods that is limited to specific production lots.
None of Hill's dry dog foods, cat foods or treats were affected, according to the company.
Dogs who eat too much vitamin D can experience vomiting, loss of appetite, increased thirst, frequent urination, excessive drooling and weight loss, according to the Food and Drug Administration. High doses of the vitamin can also cause kidney failure.
After the initial recall announcement earlier this year, Hill's faced backlash from pet owners and veterinarians that the company was slow to communicate the issue.
"We understand that this recall has caused pet parents considerable anxiety and that the well-being of their pets may have been affected ... we are working to make this right," company vice president Jesper Nordengaard said in a statement.
In December, several other dog food brands also recalled pet food also over toxic levels of vitamin D.
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This article originally appeared on USA TODAY: More dog food recalled over potentially toxic vitamin D levels, Hill's Pet Nutrition says