Our health care team at St. Francis Vet Hospital all have one thing in common – they are passionate about pets! From our highly experienced vets, to our dedicated nurses/kennelman and welcoming reception staff, everyone at St Francis Veterinary Hospital works together to provide you and your pet with the best possible care.

Our team is dedicated to providing a service to our patients and clients of the highest possible standard. The team continually review their facilities, equipment and training in order to implement their policy of always striving to exceed the expectations of all who visit the hospital.

Our comprehensive patient record system allows us to care for your pet as a team, however you can request which vet you would like to see, and our friendly reception team will gladly assist you with booking your appointment.

Dr Simon Rigby

BVSc (Hons)

Dr Simon Rigby graduated from Onderstepoort in 1999 achieving a Distinction in Small Animal Medicine. Simon was a part of the clinic group that was awarded the Final Year Clinic Group of the year award. After graduating, he registered with the Royal Veterinary College in the United Kingdom and worked at the Burghley Veterinary Centre for four and a half years, before returning back to South Africa.

Simon joined St Francis Veterinary Hospital as an assistant in December 2003 before becoming a Junior Partner in February 2006 and then a Senior Partner in 2008. During this time, he studied for and achieved his BVSC (Hons) in veterinary science.

He was a nominee for the 2007 Edenvale and Bedfordview Rotary Community Service Award and is also a member of the South African Veterinary Association, serving on the committee for 6 years between 2005 –2011. Simon is also a member of the Institute for Veterinary Practice Development (IVPD) serving as a director from 2011-2015.  His passion lies mainly with small animal medicine with an interest in preventative and geriatric health care. He is married with 2 daughters and shares his home with three cats and 1 dog. When time allows, he enjoys a competitive game of golf.

Melissa Lehman Calitz

Melissa Lehman Calitz has been a valued member of St Francis Veterinary Hospital since 2008 and has worked in the veterinary field for over 10 years, gaining experience in all areas of a veterinary practice and continues to attend professional seminars on a regular basis.

“A different day, a different hat” – human resources, facilities repair, budgeting, marketing, project management, client relations- you-name-it!  Working together with our Owners, Dr Simon Rigby and Dr Marlene Norton, Melissa makes sure we have our bases covered. Melissa began her journey as a veterinary receptionist – part time while studying through UNISA, and quickly worked her way up to Practice Manager.  She passionately believes in our mission to provide the highest quality of patient care in a compassionate environment that provides exceptional client service and education.

Upon matriculating from Edenglen High School Melissa completed a diploma in Travel and Tourism with Hartwell Business Institute for which she graduated Cum laude. Her passion for travel inspired her to explore America where she joined Greencove girls summer camp coaching tennis, one of her hobbies she enjoys when time allows it. Upon returning home she continued her studies and completed her degree in Public Relations with Management/Marketing as a sub division through the University of South Africa (UNISA).

Melissa has a passion for animals and runs our very successful petslimmer programme, she has over the years helped many pets in achieving their goal weight. Outside of the practice Melissa enjoys everything outdoors, from fresh farmers markets to country getaways, scuba diving and of course building memories with her husband and son.

Dr Leigh-Anne Ehmke


Dr Leigh-Anne Ehmke joined the St Francis family in January 2019. Leigh-Anne grew up in Sandton and matriculated from St Mary’s School for girls in Waverley where she obtained 7 distinctions.

Leigh-Anne has a huge passion for sport! She was involved in the Onderstepoort girls’ soccer team and enjoys watching Liverpool with her family. Dr Ehmke commented “No one is perfect, however being a Liverpool fan is close enough”. When time allows it, she enjoys a game of tennis or league netball with her friends.

2009 -2011 Dr Leigh-Anne completed a Bachelor of Sciences specialising in genetics with distinction. In 2011 she was awarded the Genetics Achievement Award which is given to the most outstanding final year BSc student in Genetics. Dr Leigh-Anne graduated from Onderstepoort in 2016 and spent her CCS year working at the PDSA hospital in Bridgetown, Cape Town. In 2018 she joined Bryanston Veterinary Hospital as an intern, this provided her an opportunity to improve her veterinary skills in a busy referral centre.

Her passion is primarily in surgery and her future plans in the veterinary field will be to further herself in this area. Dr Leigh-Anne shares her home with her 5-year-old cat Lilla.

Dr Sanam Daya


Dr Sanam Daya joined the St Francis Family in January 2019. Sanam grew up in Durban and matriculated with full colours in Academics. In 2017 Dr Daya qualified from Onderstepoort as a Veterinarian after which she completed her community service year at Kwaggafontein Veterinary Clinic and Sybrandskraal Veterinary Clinic.

Her time working at both these clinics has afforded her with the opportunity of gaining experience in primary animal health care and minor surgeries. Dr Sanam treated the production and companion animals of the area and educated the community on basic animal handling and welfare as well as farm management. Her passion lies with small animal medicine and she is very eager to learn from the highly experienced owners of St Francis Vets with their high standards of patient care and medical practice. Sanam enjoys spending time with her family and especially enjoys being the favourite Aunty. When time allows it, she enjoys sitting down with a good book or cooks up a storm.

Dr Daya would like to focus her career on the following quotation:

“No matter how much experience you have, how many degrees you have, or how well known you have become – there is always something new to learn.” – Laura Spencer

Dr Marissa van der Merwe


Dr Marissa grew up in KwaZulu-Natal and matriculated as her school’s Dux-Pupil. After school she completed a BSc Zoology degree at the North West University where she received the Faculty of Natural Sciences award for the Best Final Year Student. She then went to study Veterinary Science at Onderstepoort where she served on the House Committee for several years and was a part of the clinic group that received the Final Year Clinic Group of the Year award. She qualified as a veterinarian in 2000 and left South Africa to work as a vet in Birmingham, United Kingdom.

Upon returning to her home country in 2003 she worked at various clinics in Pretoria before moving with her husband to Knysna , Western Cape in 2005. Here she worked at the Garden Route SPCA as well as in private practice before moving to Cape Town in 2008. There she worked at various clinics in Gordon’s Bay, Somerset West and Strand before relocating with her family back to Gauteng in 2017. She joined the St Francis team in July 2019.

Dr Marissa has a keen interest in surgery, diagnostic imaging and dentistry.

She is married with one daughter and shares her home with one cute Schnauzer, Heidi and her old cat, Ziggy.

In her spare time she loves to be creative completing cross stitch work, crocheting, building puzzles and enjoys singing Her family loves to go camping and enjoys being outdoors in nature.