Vetoryl

Vetoryl for dogs

What does Vetoryl do?

Vetoryl reduces excess cortisol production in dogs with Cushing’s disease. 

Normally, cortisol is produced by a system of enzymes in the adrenal glands. Cortisol has many important functions (e.g. regulating immunity, metabolism and stress responses). However, if the adrenal gland overproduces cortisol, Cushing’s disease (hyperadrenocorticism) occurs.

Vetoryl is a man-made steroid that binds to cortisol-producing enzymes. As a result, these enzymes cannot bind to the molecules that they use to produce cortisol. Thus, cortisol production is decreased. 

In this way, Vetoryl manages the signs of Cushing’s disease (e.g. excessive drinking and urination, skin problems). Vetoryl also reduces the risk of serious consequences from untreated Cushing’s (e.g. diabetes, blood clots). It’s important to understand that Vetoryl manages the signs of Cushing’s diseases, but does not cure it.

What is Vetoryl used for?

Vetoryl is prescribed to dogs with Cushing’s disease. It regulates cortisol production in both types of Cushing’s disease (pituitary-dependent and adrenal-dependent Cushings). This addresses the symptoms of Cushing’s disease (e.g. increased thirst, appetite, lethargy).

For more information about the types of Cushing’s in dogs, our e-learning course for pet owners can help.

What are the side effects of Vetoryl in Dogs?

As with all medicines, Vetoryl can have side effects. These side effects of Vetoryl affect about 40% of dogs on Vetoryl and can be serious, so they’re worth understanding if your dog is on Vetoryl.

Known side effects of Vetoryl are:

• Vomiting or diarrhoea: Up to 1 in 100 pets may have temporary digestive upset when starting Vetoryl. This should improve as their body adjusts to the medication but may require a dose change. Prolonged, frequent or severe vomiting/diarrhoea should be reported to your vet immediately, as this is a sign of Addison’s disease (see below).
• Lethargy or weakness: Occasionally, pets might show signs of tiredness. This is usually mild and temporary, but it’s crucial to monitor to see if it develops to prolonged lethargy as this can be a sign of Addison’s disease (see below). Up to 1 in 100 dogs may show signs of lethargy as a side effect of Vetoryl.
• Little or no appetite: As Vetoryl reduces excess cortisol levels, your dog’s appetite and water consumption should return to normal. However, if your dog has below-normal appetite and water intake, contact your vet immediately, as this can be a sign of Addison’s disease.
• Unmasked arthritis: High cortisol can act as an anti-inflammatory, improving arthritis symptoms. Therefore, Vetoryl may sometimes unmask hidden arthritis in dogs. Signs include a stilted gait, stiffness, and not wanting to exercise as often. Your vet can treat arthritis pain, so if you notice this side effect of Vetoryl you should contact them.
• Incoordination and wobbliness: This is a rare side side effect (up to 1 in 1000 animals), and generally mild. However, you should report incoordination (aka ataxia) to your vet.
• Bloating: Bloating affects approximately 1 in 1000 dogs on Vetoryl and is usually mild. You should report this side effect to your vet if you spot it.
• Muscle tremors: Reported in 1 in 1000 dogs, muscle tremors are usually mild.
• Sudden death: There are isolated reports of sudden death of dogs on Vetoryl, especially dogs who are also on ACE inhibitors (see ‘Which Pets is Vetoryl Not Suitable For?‘ below).
• Cortisol gets too low: Another really important side effect of Vetoryl is abnormally low cortisol, aka Addison’s disease. This happens when too much Vetoryl is given for your dog’s Cushings, and their cortisol production stops too much.
  
  Addison’s disease usually presents in two forms. It can manifest as a collection of vague clinical signs (e.g. diarrhoea, vomiting, trembling, weakness) that mimic other diseases. However, if cortisol levels become critically low, an “Addisonian crisis” can be triggered. Dogs in an Addisonian crisis display signs such as severe vomiting and diarrhoea, sudden weakness or even collapse. Addison’s disease is an emergency that requires immediate veterinary attention.

Remember, not all pets will experience these side effects, and the benefits of using Vetoryl often outweigh the risks, especially as Cushing’s disease can cause further health risks. That said, your vet should closely monitor your pet if they’re on Vetoryl and will want to hear of any side effects you see, whether they’re listed above or not.

The Veterinary Medicines Directorate (the VMD) collects reports of suspected side effects, and monitors pet drug safety. As a pet owner, you can report a suspected side effect to the VMD yourself, or ask your vet to do it for you. For more information about drug monitoring from the VMD, our article on reporting pet drug side effects can be helpful.

Which pets is Vetoryl not suitable for?

Vetoryl is not generally suitable for dogs with certain health issues or who are taking other medications, like:

• Dogs with liver or kidney issues
• Pregnant or lactating dogs, or those intended for breeding
• Dogs that are allergic to Vetoryl or any of its ingredients
• Dogs taking ACE inhibitors, such as benazepril (Benazecare, Arixil, Banacep, Benazevet, Benefortin, Cardalis, Fortekor (including Fortekor Plus), Kelapril, MiPet Benazepet, Nelio, Prilben) and enalapril
• Dogs taking potassium-sparing diuretics such as spironolactone (Cardalis, Prilactone)
  

However, Vetoryl can still be given to these dogs if a vet has done a risk-benefit analysis and decided that, on balance, a Vetoryl prescription is still in your dog’s best interests.

How to give Vetoryl safely

1. Follow vet instructions: Always use Vetoryl exactly as your vet has prescribed. This includes the right dose and frequency. Never adjust the dose on your own, even if your dog seems to be feeling better or worse. If you aren’t sure of the dose prescribed, please call your vet to confirm.
2. Do not break capsules: Vetoryl capsules should be given whole. You should not attempt to break or split trilostane capsules.
3. Give Vetoryl with food: Vetoryl is more effective when given with food. Generally, Vetoryl is best given in the morning – but do check with your vet regarding the best timing for your dog.
4. Check with your vet if giving anything else: There is a higher risk of side effects if Vetoryl is given along with certain drugs (e.g. ACE inhibitors like Benazecare). Therefore, check with your vet before giving Vetoryl if your dog is on any medications. While your vet should be aware of other drugs your pet is on, it’s always worth double-checking in case there’s been a miscommunication somewhere. If your dog is on supplements or non-prescription treatments you should also tell your vet when they prescribe Vetoryl, as they may not be suitable to be given together.
5. Storage and Handling: Store Vetoryl  according to the instructions on the label, usually in a cool and dry place. Make sure it’s out of reach of children and other pets. Women who are pregnant or are intending to become pregnant should not handle Vetoryl.
6. Report any accidental overdose to your vet immediately: If you have mistakenly given too much Vetoryl, report it to your vet as soon as you realise the error. Your dog may be at risk of Addison’s disease, which can be serious. Your vet may recommend blood tests, intravenous fluids, medication, or monitoring, depending on the severity of the overdose.

How much monitoring do pets need on Vetoryl?

Because every case of Cushing’s is different, the dose of Vetoryl varies depending on the individual dog. Some dogs need more Vetoryl than others, even if they’re the same size. This means your vet will need to ‘titrate’ the Vetoryl dose to your dog’s response – they’ll choose a starting dose, then check their blood a few days later. If all is ok, they’ll check the blood again a little while later again. Usually, blood results are needed at 10 days, 4 weeks, and 12 weeks, and it’s then recommended that dogs have tests every 3 months to make sure the right dose is being given. If a dose change is needed, dogs will need to start this testing regime again.

What does Vetoryl cost?

The cost of Vetoryl depends on the dose your pet needs, which varies with their individual response to it. A 10kg dog usually starts at a dose costing £60-80 per month, but this may not be the dose they require long-term. Large-breed dogs of 50kg+ are likely to start at a dose costing over £150 per month. It is therefore fairly expensive to treat a dog with Cushing’s disease in the UK.

You don’t have to buy Vetoryl from your vet, and it may be cheaper online, but if you choose to buy it elsewhere your vet will need to give you a written prescription. Vets are allowed to charge a reasonable fee to cover their professional time checking doses and writing a written prescription for use elsewhere. Don’t forget to include this charge and postage/dispensing fees when working out the cost of Vetoryl from your vet vs online.

Vetoryl FAQs

Vetoryl Alternatives

Unfortunately for pet parents, there aren’t many good alternatives to Vetoryl for Cushing’s disease in dogs, and Vetoryl is the only Cushing’s treatment licensed by the VMD.

That said, vets may recommend using the following treatments off-license if Vetoryl isn’t working:

• Mitotane
• Ketoconazole

In addition, for some types of Cushing’s, surgery may be a permanent option to treat it.

For more information about the Cushing’s treatment options, our vet-written e-learning course about Cushing’s can help.

Vetoryl Datasheet

All drugs have a manufacturer’s datasheet, which gives information about the drug’s use and possible side effects. There is usually one in your Vetoryl box, but if you have lost it you can click on the button below to be taken on an online version.

Information for pet parents about Cushings

If your dog is on Vetoryl, you might be interested in learning more about their condition with our interactive, vet-written courses. We’ve discussed everything vets and modern science know about Cushing’s disease in dogs, and you have access to it – including all updates – for the rest of your pets’ life.

---

Please note that the information contained herein is provided for informational purposes only. Although it has been written by a vet, we cannot consider the individual nature of your pet’s problems so it does not constitute veterinary advice. If you have questions about your pet’s medication or their health you should contact a vet, who will be able to help.

---