A South Otago dairy farmer is mourning the death of his pet dog Oscar. Harry Cotter talks to reporter Southern Rural Life’s Shawn McAvinue about how a sweet-smelling calf milk replacer can be lethal to man’s best friend.

A South Otago dairy farmer is warning about the dangers of calf milk replacer after the death of his beloved pet dog.

Harry Cotter contract-milks 550 cows on a 150-ha farm in Stirling.

On the farm about two years ago, his pet Labrador-cross dog Oscar licked some leftover milk replacer in a calf feeder.

About 30 minutes later, after noticing Oscar panting and dragging his legs, he rushed him to a veterinarian.

The vet gave Oscar medication to make him throw up and discovered the milk replacer in his vomit.

Cotter was unaware some milk replacer was toxic to dogs.

 “There’s no treatment for it - they have to give them an intravenous drip and you hope for the best.”

Oscar recovered and returned home.

Cotter inspected the bag of replacer and discovered a warning to keep it away from dogs on the bottom of the bag “in very, very, very small writing - smaller than the instructions”.

To stop Oscar from eating any more of the replacer, which had a vanilla scent, he installed a range of strict measures, such as locking it away.

“You don’t want to take any risk - he’s a member of the family.”

Despite his vigilance, he noticed Oscar panting and had limp limbs last month.

Oscar was rushed to a vet and made to vomit, which showed the nearly 40kg dog had ingested a tiny amount of the replacer.

As the vet worked on him, Oscar’s heart rate dropped and he died.

“It was just enough to shut his heart down - the poor bugger.”

His vet told him as Oscar’s heart was damaged from previously eating milk replacer, existing scar tissue on his heart would have ripped from the second attack.

Many people in the rural community were unaware of the toxicity of replacer to dogs and he hoped talking to Southern Rural Life would save the life of at least one dog.

Cotter got Oscar cremated because he was seeking his next step in the industry, such as an equity partnership, and was expecting to move farm at the end of the season and wanted Oscar to come with him.

Labrador-cross dog Oscar died after eating calf milk replacer in South Otago. Photo / Supplied

Oscar was 6 years old when he died and had been part of the family since he was rescued from the pound.

“He’s been part of my life since he was a puppy.”

New Zealand Veterinary Association head of veterinary services for companion animals Sally Cory said some calf milk replacers contained substances called ionophores, which are compounds added to reduce the risk of significant clinical coccidiosis infection in calves.

Ionophores could be toxic to species such as alpacas, cats, dogs, cats, goats, horses, llamas and sheep.

Dogs were particularly sensitive to the effects of ionophores in calf milk replacers, and clinical signs could develop within 12 hours of ingestion. Neurological signs usually developed first with generalised weakness and wobbliness.

Dogs would develop weakness in all four limbs, which could progress to full paralysis.

Drooling was common, along with a loss of tongue control.

Body temperature would increase and dogs would develop breathing problems as a result of paralysis of the muscles which control breathing.

Often a dog’s pupils were different sizes and it becomes especially sensitive to external stimuli, such as noise and sudden movements.

The paralysis could be profound, and dogs were often left able to only wag their tails and move their eyes.

Ionophores could also have an effect on the heart muscle, leading to heart problems.

Milk replacer should be mixed at the correct ratio of water to powder for the age and weight of the animal, as indicated by the instructions on the label.

Open bags of milk replacer should be stored in a container which could be completely sealed and out of reach of all animals.

Farmers should never leave empty bags or storage containers lying around as the remnants of the product could be toxic.

All equipment used to prepare and store milk replacer should be immediately cleaned to ensure dogs were not able to access milk remnants.

If a dog had recently accidentally ingested milk powder, it should be taken to a vet, where it might be made to vomit to help retrieve some of its stomach contents and reduce the absorption of the potential toxins.

Activated charcoal might then be given to help bind any further toxins within the gastrointestinal tract and reduce the risks of absorption.

“If clinical signs develop then unfortunately there is no specific antidote.”

Treatment would be supportive and often intensive. Animals might be in hospital for extended periods of time and could be left with ongoing heart problems if they survived.