Before administering Tildren or Osphos to our patients, we always warn clients that their horse might colic during or after treatment. Data shows that 44% of horses will colic from Tildren 0.9% from Osphos, but the colic is short-lived and easily treated. It is crucial to remember that non-steroidal anti-inflammatories such as bute, banamine, or equioxx must be AVOIDED for 48 hours. This is to protect your horses’ kidneys after Tildren or Osphos. We often recommend bloodwork to rule out kidney disease prior to this treatment.
So why do horses colic after Tildren or osphos is given?
The simple answer is because Tildren and Osphos alter Calcium levels in the bloodstream. This creates intestinal muscle spasm which slows down gastrointestinal movement….If you want to learn more about the specific mechanisms that cause colic keep reading….
It is important to know how the drugs are absorbed in the body. Lets start with the basics: Tildren (Tiludronate) or Osphos (Clodronate) are bisphosphonates which inhibit osteoclast activity in bone. Once injected, a portion of Osphos and Tildren are absorbed directly into the bone unchanged. The other portion of Tildren and Osphos is unable to be filtered into bone because it binds to proteins, minerals, and electrolytes including calcium in the bloodstream. A transient hypocalcemia can occur in some horses due to this calcium binding.
This transient hypocalceima is responsible for most of the colic signs horses show. Hypocalcemia will decrease smooth muscle excitability in the intestinal tract leading to slower moving intestines (ileus) and GI tract pain. Some horses will develop muscle tremors/fasciculations as a result of the low calcium. These signs are short lived due to the short half life of Tildren and Osphos, so these adverse affects should only last 2-4 hours after administion.
How long does colic after Tildren and Osphos last?
The fraction of Tildren or Osphos that is not absorbed into the bone right away is eliminated quickly within 2-4 hours after administration. You should monitor your horse for 2-4 hours after Tildren or Osphos is administered for signs of colic. If your horse colics after Tildren or Osphos is given, be sure to call your veterinarian.
Is the mild colic worth the risk of administering Tildren or Osphos?
It is important to remember that colic is mild and always short lived. The effects of Tildren or Osphos in the bone are long lived and even found to be active in the bone 2 years later. There are no other drugs as effective as these for treating bone disease.
If you have any questions please contact us at 561.515.2685