The world of veterinary medicine is constantly evolving. Stem cell therapy has been used with good success in human medicine, and we are now seeing options open for animals, too. The science of regenerative medicine is relatively new, and there is a lot still to learn. But with pet owners wanting to explore all the options available to them, we thought it would be worth delving into stem cell therapy and its uses in more detail. 

What is stem cell therapy? 

Stem cells are self-renewing, unspecialised cells that, under the right conditions, can become a specific tissue or organ cell. This process is called differentiation, and it is controlled by the way the cell’s genes interact with its surroundings. Signalling pathways involving proteins from other nearby cells cause the stem cells to develop the features of specialised cells. For example, stem cells can turn into chondrocytes to form new cartilage, or they could become liver cells. Think of stem cells as a way of repairing or renewing existing damaged tissues, hence the term ‘regenerative medicine’. 

In stem cell therapy, stem cells from the body are placed in an area that is damaged, such as a joint suffering from ligament disease or osteoarthritis. These stem cells are currently gathered from the bone marrow and fat (adipose tissue) in cats, dogs, and horses. While other cells from another animal may be used, often it is the pet’s own cells that are utilised, which minimises the risk of adverse effects. More on how this works later! 

How can stem cell therapy be used in pets? 

Stem cell therapy has various potential uses in our pets; however, it is currently most often used to treat osteoarthritis in dogs. Stem cells can be used in a variety of joints in the body to help treat this condition. They have potent anti-inflammatory effects in arthritic joints with the potential to form new cartilage, a substance essential to joint health. This can lead to a better range of motion, increased comfort levels, and better mobility, and may make them less reliant on painkillers.  

Clinical research is ongoing, but other potential uses may include –  

  • Ligament injuries 
  • Spinal cord injuries 
  • Bone repair 
  • Liver disease 
  • Kidney disease 
  • Cardiomyopathy (a type of heart disease affecting the heart muscle) 
  • Diseases of the skin 
  • Inflammatory gut diseases 

Treating cancer with stem cells is not advisable at this time, as the stem cells could encourage more growth and spread of the cancerous cells (a phenomenon known as “neoplastic promotion”).  

Accessing stem cell therapy 

Not all vets routinely offer stem cell therapy, and they may suggest referring you to a practice that carries out this sort of procedure. Your vet will also need to ensure they have made a definitive diagnosis of your pet’s problem and explored other treatment options with you. If your pet is deemed suitable, then they will usually undergo the following procedures (this describes stem cell collection from fat) – 

  1. An anaesthetic to allow collection of fat, usually from a small incision in the groin, abdomen, or shoulder region. 
  1. These fat cells are transported to a specialist laboratory where the stem cells are extracted and made into a concentrated form. This process could take a few weeks, depending on the number of cells required. Larger numbers of cells are needed for multiple joints or for spinal injections. These cells are tested for sterility and cryogenically frozen before being sent back to the veterinary practice. The stem cells can be stored in frozen form for an extended period of time if necessary.  
  1. The stem cells will need to be injected into the affected area of your pet. This usually involves another anaesthetic to allow for sterility and accuracy. The vet may use an ultrasound probe to help guide the needle into the right position. Getting the injection in the right place is crucial, which is why the vet performing the procedure must be suitably competent.  

There shouldn’t be a need for pets to be hospitalised for long periods during the process. Most are treated as day patients and recover quickly. Also, a sample of the patient’s stem cells may be stored at the lab in case more are needed in the future. This saves the animal from having to undergo another ‘harvesting’ procedure.  

Is stem cell therapy safe for cats and dogs? 

Stem cell therapy is generally considered safe with minimal risks. Using the pet’s own cells means the risk of rejection is extremely low. Most of the reported side effects are due to the mechanical action of the injection into the joint. These include mild pain, joint swelling, and the risk of introducing infection.  

Your vet will also discuss any risks associated with the sedation or anaesthetic, which may be dependent on your pet’s health and any concurrent medical issues. 

Will stem cell therapy help my pet? 

It is impossible to predict how each animal will respond to stem cell therapy. It may depend on multiple factors, including your pet’s age and breed, as well as the type of disease being treated and how advanced it is. Some patients may show improvement after just a few days, and others could take several weeks. They could also show initial improvement and then relapse. 

It is important to be aware that not all animals show a good response to stem cell therapy, so you must manage your expectations from the outset. This is certainly not a miracle, science-fiction cure-all medicine. But in some cases, it could prove to be very helpful. 

As such, the British Small Animal Veterinary Association (BSAVA) released a statement which includes the following: ‘Autologous, allogenic and xenogeneic mesenchymal stem cell therapies show promise for treatment of a variety of canine and feline conditions. Although supportive data is available for canine osteoarthritis, the BSAVA would still encourage further well-designed clinical trials to fully establish the role of these cell types in clinical management of this condition.’ 

The BSAVA is suggesting that more research is needed in this field of medicine to truly understand its applications. They also go on to say that stem cell therapies being used outside of canine osteoarthritis should not be used routinely at this time. 

The BSAVA also hints that other treatment options should be considered ahead of stem cell therapy in some cases – 

‘Veterinary medicines containing stem cells have been authorised in the UK for use in several animal species and indications. However, it may be appropriate under certain circumstances to use alternative treatments which may include cell therapies (e.g., use of an autologous stem cell product from a non-food animal stem cell centre) or conventional non-biological veterinary medicines (e.g., non-steroidal anti-inflammatory drugs).’  

Stem cell therapy is clearly not a first-line treatment for all animals yet, and owners should be counselled on other, more traditional treatment options first. 

Pros and cons of stem cell therapy 

Let’s summarise some of the pros and cons of this type of treatment in the management of osteoarthritis:

Pros 

  • Potential for long-term results – the effects of stem cell therapy may last for months or years, according to some studies. This can make this type of treatment cost-effective in the long term and may reduce the requirement for other treatments needed. 
  • Non-invasive option – Stem cell therapy can be much less invasive than other surgical interventions. The recovery is relatively easy, and the procedure is much shorter than more major joint surgeries. 
  • Reduced pain and inflammation – Stem cells can reduce pain and inflammation, and they may even slow disease progression. An improvement in quality of life is noted in successfully treated pets. 
  • Improved mobility – With a reduction in pain and inflammation comes an improvement in mobility. Regenerated cartilage in the joints reduces friction, allowing for smoother movements. Pets that can move comfortably will be happier and less prone to other issues like weight gain and muscle wastage. 
  • Low risk of side effects – Using an animal’s own cells means this treatment carries a low risk of any side effects. Those experienced are usually mild and related to the injection process itself. 

Cons 

  • Cost – The upfront cost can be prohibitive for many pet owners. It’s not clear whether all pet insurance companies cover stem cell therapy currently, so owners would need to check this. 
  • Availability – Stem cell therapy is not available in every veterinary practice. Often, pets will need to be referred to a clinic that regularly carries out this sort of procedure, due to its technical nature. 
  • No guarantees on effectiveness – As discussed previously, effects are variable between different patients. While some respond really well, this is not true for all. In some cases, stem cell therapy may help improve your pet’s condition, but other treatments may still be required alongside. 
  • Experimental treatment – In some countries and US states, stem cell therapy is still classed as an experimental treatment. This means that it may not have undergone the same rigorous testing and approval as other conventional treatment options. This is still certainly the case when it comes to treating conditions other than osteoarthritis. According to one source ‘It is not currently a legal requirement for canine stem cells in the UK to be manufactured to Veterinary Medicines Directorate standards (as it is in equines), but centres adhering to these standards are recommended’. 

It is worth noting that any form of treatment or medication will have its own list of pros and cons. There is no one-size-fits-all solution when it comes to osteoarthritis management. Your vet is best placed to advise you on the various options available to your pet, especially as some treatments are more suited to certain animals than others. 

Summary 

Stem cell therapy is certainly exciting, and while its uses in osteoarthritis management are evident, more research is needed into the treatment of other conditions. If you are interested in stem cell therapy for your pet, then have the conversation with your veterinary practice. Even if they can’t perform the treatment themselves, they may be able to refer you somewhere that can. 

Remember, the effects of stem cell therapy will vary between patients, so it is important to manage your expectations when having these discussions. Osteoarthritis can be a complex disease to manage, and many pets require a multi-modal approach to their condition. As well as stem cell therapy, this may include lifestyle changes, weight loss, traditional pain relief, joint supplements, and complementary therapies like hydrotherapy.