Table 1.

A collection of selected papers describing the use of MSCs in the treatment of OA in animals. Abbreviations: OA —osteoarthritis, AD-MSCs—adipose derived mesenchymal stem cells, PBS—phosphate buffered saline, PRGF—plasma rich in growth factors, PRP—platelet rich plasma, HA—hyaluronic acid, UCB-MSCs—umbilical cord blood mesenchymal stem cells, SVF—stromal vascular fraction, BM-MSCs—bone marrow derived mesenchymal stem cells, PB-MSCs—peripheral blood derived mesenchymal stem cells.

Disease	Cell Therapy and Type of Injection	Species	Number of Test Animals	Control Group	Number of Control Animals	Observation Period	Effect of Therapy
OA hip joint [40]	autologous AD-MSCs, 4.2–5 × 106 cells, single intraarticular injection	dog	Group A (18 animals in total divided in groups)	yes, injection of placebo (PBS)	Group B	90 d	Positive therapeutic outcome of applied therapy.
OA elbow joint [95]	autologous AD-MSCs 3–5 × 106 viable cells, single intraarticular injection	dog	14	lack	0	30, 60, 90, 180 d	Positive therapeutic outcome of applied therapy.
Degenerative fetlock joint disease [96]	allogeneic chondrogenic induced MSCs 2 × 106, single intraarticular injection	horse	50	yes, injection of placebo	25	3, 6, 12, 18 w	Significant improvement in motor skills in the group of animals treated with MSCs.
OA hip joint [41]	AD-MSCs 30 × 106 versus plasma rich in growth factors (PRGF), single intraarticular injection	dog	18	yes, injection of PRGF	17	1, 3, 6 m	Significant improvement in motor skills and the abolition of pain sensation in both groups.
OA elbow joint [13]	autologous AD-MSCs 3–5 × 106 cells, single intraarticular injection with addition of PRP or HA as a scaffolds	dog	4	lack	0	1, 4 w	Positive therapeutic outcome of applied therapy.
OA metacarpophalangeal joint [93]	allogeneic UCB-MSCs, 10 × 106 cells, single and repeated intraarticular injections	horse	14	MSC1 group received MSCs in M0 and placebo in M1 (D-PBS).	14	1, 2, 6 m	Positive therapeutic outcome in both test groups.
OA elbow joint [94]	allogeneic UCB-MSCs 7 × 106 cells, single intraarticular injections	dog	30	saline (0,9% NaCl) placebo	25	1, 3, 6 m	Reduction in symptoms related to OA in the group of dogs that received a single injection of UCB-MSCs.
OA hip joint [97]	autologous stromal vascular fraction (SVF) 2–5 × 106 and allogeneic AD-MSCs 2–8 × 105, single acupuncture point injections	dog	9	lack	0	7, 15, 30 d	Positive therapeutic outcome of applied therapy.
OA lower hock joint [42]	autologous AD-MSCs, 5 × 106 cells, single intraarticular injection	horse	10	Horses in group II received betamethasone intraarticularly, animals from group III had only limited movement during observation.	6	30, 60, 90, 180 d	Long-term benefits of MSCs therapy have been observed, as opposed to the short-term effects of steroids.
OA hip joint [43]	autologous AD-MSCs, 30 × 106 cells, single intraarticular injection	dog	8	yes	5	30, 60, 90, 180 d	Increase in functionality and less discomfort associated with pain sensation caused by OA were found.
OA medial femoral condyle defect [98]	autologous BM-MSCs 20 × 106 with addition of HA	horse	10	In the control group, only the intra-articular injection of HA was performed in the opposite stifle joint.	10	12 m	No significant clinical improvement was found after the completion of the follow-up.
OA stifle joint [99]	allogeneic UCB-MSCs, 1 × 106 cells, single intraarticular injection	dog	4	Yes, saline injection of the same volume as in the group of animals tested.	4	3, 7, 14, 28, 35 d	Positive therapeutic outcome of applied therapy.
OA stifle joint [100]	allogeneic AD-MSCs 10 × 106 with the addition of PBS, multiple intraarticular injections	dog	6 dogs in group III MSCs with PBS and 6 dogs in group IV MSCs and PRP	Yes, intra-articular injection of PBS in the control group.	6 dogs in group I PBS and 6 dogs in group II PRP	1, 2, 3 m	Beneficial effect of the medicinal PRP and MSCs preparations were found.
OA spinal region [101]	Allogeneic SVF-MSCs, 2 × 106 cells per 1 kg of body mass, single intravenous injection	dog	10	Yes, blood samples were taken from the control animals to measure the level of VEGF.	10	2, 8, 24 w	Positive therapeutic outcome of applied therapy.
OA stifle, fetlock, pastern and coffin joints [102]	allogeneic PB-MSCs (chondrogenic induced and native) with PRP, single intraarticular injection	horse	165 (stifle n = 30, fetlock n = 58, pastern n = 34, coffin n = 43)	lack	0	6, 18 w	Positive therapeutic outcome of applied therapy.