What is Nutritional Secondary Hyperparathyroidism (NHSP)?
Nutritional secondary hyperparathyroidism (NSHP) is unfortunately a common type of metabolic bone disease that can occur in any animal but is most often seen in reptiles and amphibians. This condition most often occurs in captivity when an animal is not receiving the proper husbandry. NSHP can occur when the animal’s diet does not have enough calcium, or vitamin D3, or in the case of many reptiles when they do not receive enough UVB (ultraviolet B) light. Vitamin D3 is required by the body for calcium absorption, so as a result the parathyroid gland, which is found in the neck with the thyroid, begins to produce more parathyroid hormone (PTH). The primary function of the parathyroid gland is to tightly maintain calcium levels and keep them balanced. As a result of the decreased calcium and lack of vitamin D3 the secreted PTH stimulates osteoclasts in the bones, where most calcium is found, to begin resorbing the bones breaking them down causing the calcium to be released back into the bloodstream. Calcium is extremely important throughout the body where it is required for nerve transmission, muscle function, blood clotting and a multitude of other vital bodily functions. While the calcium needs to be in the blood it does so at the expense of the bones.
Why do we see NSHP in Wildlife?
When the bones are broken down to provide calcium it causes them to lose density making them more susceptible to injury. Additionally, there are developmental deficiencies associated with growth that can occur too. All of these make the lives of animals very difficult. NSHP is not as prevalent in the wild, because the animals tend to get enough sun and eat a proper diet. There are two main reasons we see this, first is when people have a pet and they don’t do proper research on housing and diet requirements and therefore don’t meet the needs of their pet. The second reason we see this is due to well-meaning individuals finding wildlife and then proceeding to care for them or keep them in captivity instead of bringing them to a licensed rehabilitator. Wildlife requires specialized diets and housing that are hard to meet in captivity and while people try their best, they often fail to meet the needs of these animals and don’t realize that for most wildlife, permits are needed to care for them, so keeping them in captivity is actually illegal if you don’t possess the proper permits. To further illustrate the effects of NSHP, we will review two cases we have recently seen in the Wildlife Medical Clinic.
Virginia Opossum Case
On September 9th, 2024, we received a juvenile male Virginia opossum that a finder found in their yard struggling to walk. Upon exam he struggled to walk and lacked coordination in his back legs. Additionally, his face was swollen and asymmetrical. Due to the possible orthopedic issue and significance of ataxia we opted to take radiographs.
The radiographs showed that the opossum had a decrease in bone density, and severe malformations of the long bones primarily at the femoral head which is the part of the femur that connects to the hip. They were so degenerated that they appeared to be absent. All the joints appeared to be affected in some way, but that was the most notable location. These changes to the bones and the facial asymmetry led to our diagnosis of nutritional secondary hyperparathyroidism. Our belief is that he was kept as a pet for a significant amount of time when he was younger by someone who did not have the proper knowledge or credentials and then he was released. He also had a very high body condition score indicating he ate well, which would not have been possible on his own, in the wild, due to his musculoskeletal abnormalities. Even though he ate well, he did not receive the proper nutrients needed for bone formation and maintenance. Unfortunately, due to the severity of the malformations and the fact that multiple joints were affected the most compassionate care we could provide was humane euthanasia. He likely had arthritis, which is painful and overall had a poor prognosis for surviving in the wild as the damage done was irreversible.
Common Snapping Turtle Case
While the Virginia opossum did not have the outcome we hoped for, our next patient, a common snapping turtle, has a more positive outcome. On November 11, 2023 we received a juvenile male common snapping turtle after it was found abandoned in a vacated apartment where he was owned for around two years. He was found dry docked and severely dehydrated. Upon physical exam he was severely dehydrated, his shell appeared too small for his body and was soft and flat. Additionally, he had signs of stunted growth. All of this points to NSHP, primarily the softening of the shell and stunted growth.
This was confirmed through radiographs, which showed decreased bone density and stunted growth Fortunately, unlike the opossum the damage was reversible. He was put on a proper diet along with consistent UVB and heat and now just over a year later he has grown a considerable amount and his body condition has greatly improved. While this is great news, he still is not releasable due to his friendly nature. Because of the time he spent in captivity, he is habituated to people. We have been working on finding him a permanent home and have received interest from an out of state nature center. However, if for some reason this home doesn’t work out, we will keep looking.
Lessons Learned from these Cases
These two cases illustrate the importance of nutrition and proper care for animals. If you want to own a pet, make sure you do the proper research and have everything set up and ready for them before you bring them home. Picking out a pet should not just be done on a whim. They are living creatures that require care and work. The snapping turtle shows the importance of doing research and being committed to owning a pet. Obviously, we don’t know the circumstances of his abandonment, but this is unfortunately an all too common occurrence when it comes to reptiles. Reptiles are unique in their dietary and husbandry needs, which need to be known by the owner, or else serious health issues like metabolic diseases can arise. The case of the Virginia opossum illustrates the importance of knowing who to contact, and only taking care of wildlife if you have the proper knowledge, credentials, and permits. The WMC is built on the idea of us working with the public to better the quality of life for wildlife. If you see an animal that you think needs help, don’t try to keep it and care for it on your own, because it can put you and the animal in danger. Contact a licensed rehabilitator or reach out to the Wildlife Medical Clinic and we can help provide guidance on what to do and who to contact. We hope these cases illustrated how important animal nutrition and husbandry is, why it is best to leave wildlife in the wild, and if help is needed to please contact a licensed rehabilitator.
Written By: Dylan, Class of 2026
