As the wallaby found in East Rockaway on Tuesday recovers from starvation and steadily gains weight at the Mineola Animal Hospital, the Nassau County SPCA says it is considering criminal charges against the man they believe was responsible for its care.

When the full-grown, male wallaby was admitted to the animal hospital on Tuesday after being found inside a dog-run type enclosure in a garage on Seawane Road, it weighed 17.8 pounds, veterinarian Dr. David Kolins said.

A day later the animal, a smaller cousin of the kangaroo and a native of Australia, had gained 1.6 pounds — still far less than the “just under” 40 pounds it should weigh. The veterinarian said the wallaby has “essentially no muscle and no body fat.”

“He got lucky that the weather’s been as mild as it’s been,” Kolins said Thursday at the animal hospital. “If this was a cold winter, he’d be dead.”

The wallaby’s liver was shutting down from starvation, blood tests and an ultrasound procedure showed. Thankfully, Kolins said the cure is food and water — which the unnamed animal has been devouring “like there’s no tomorrow.” Special “wallaby chow” pellets — $36 for a 40-pound bag, $217 for shipping — were expected to be delivered soon.

“He’s marginally tougher to hold than a bunny,” Kolins said. “You can feel each individual disc in his spine.”

advertisement | advertise on newsday

On Thursday, veterinary staff fed the wallaby apples as it stared at its reflection and groomed its gray body, with a reddish pattern down its neck and back. The animal hospital had roped off a small area for it with a sheet and it occasionally hopped around.

Meanwhile, SPCA investigators are looking at both summonses and criminal charges for Larry Wallach, spokesman Gary Rogers said.

The SPCA has spoken with Wallach briefly, Rogers said, but officials don’t know how he got the wallaby or if he has other exotic animals.

Asked if Wallach had offered any explanation for the wallaby’s condition, Rogers said “not really” and declined to say where officials had spoken with him.

Kolins and Rogers both said the animal’s severe malnutrition did not occur in a matter of days or weeks. Kolins estimated “at the very least” it would have happened over months.

Now that the wallaby is safe and recovering, “we have time now to conduct a thorough investigation,” Rogers said.

If pursued, any summonses would be filed by Hempstead Town’s building department for harboring an animal that is considered wild in its natural habitat.

The U.S. Department of Agriculture filed a complaint against Wallach in 2012 for violating the Animal Welfare Act with regards to the treatment of several exotic animals — including a wallaby housed in a small enclosure — in multiple states between 2008 and 2011, according to documents. The complaint was dismissed as the parties engaged in a settlement.

The wallaby will likely be at the Mineola Animal Hospital for another week or two, Kolins said. Then it’ll head to a preserve or other program, such as the Save The Animals Rescue Foundation in Middle Island. The wallaby is expected to regain its full weight and strength through exercise, a proper diet and water.