Ivan Bridge BVSc

Neil Houston BVSc, MACVSc (EqMed), Director

Lacy Kamm DVM, MS, DACVS, Director

Jenny Sonis DVM, MS, DACVIM, Director

Kevin Miers BVSc, Director

Jeremy Bullock BVSc (Dist), BSc, Director

Felicity Wade BVSc, Director

Alex Fowler BVSc, DACVS

Ben Vosloo BVSc

Jordana Del La Varis BVSc (Dist)

Kaylin Touché DVM

Tarryn Walker BVSc

www.vetassociates.co.nz

Stable talkJuly 2020

At this time of year it is important to monitor your foal’s limbs closely. We frequently see physitis in 3-9 month old

foals, particularly the larger, rapidly-growing ones. Physitis is defined as inflammation of a physis, which is a growth plate. At the growth plates, cartilage is getting transformed into bone through a process called endochondral ossification, and the

horse is getting taller. Damage to these growth plates can result

in permanent damage to the foal’s limbs. This can be caused by excessive growth from nutrition and/or genetics, or from infection or trauma. Nutritional

causes are common and often due to excessive feeding

and mineral imbalances (mainly calcium and phosphorous). Physitis can also occur in a foal following an injury to the opposite leg due to the extra weight put on the “good leg.” The proposed mechanisms are inflammation due to excessive loading or weakened bone and/or cartilage, or a combination of these factors.

Common sites include the distal cannon bone (proximal fetlock), distal radius (proximal knee) and distal tibia (proximal hock) (Figure 1). Fetlock swelling is usually seen between 3-6 months of age, and the distal radius

» Figure 1. This foal has what we would consider good normal forelimb conformation at 3 months old. As different bones go through rapid growth at different times it is important to continually monitor your foal’s limbs through to 2 years of age. During this time angular limb deformities can develop (limbs become crooked). The white arrows show where the proximal growth plates of the knee and fetlock are.

12 Sim Road, KarakaPO Box 135 Drury, Auckland

with a satellite practice based in Kumeu

T: 09 294 7307

E: vets@vetassociates.co.nz

Equine Hospital & Referral Centre

Providing outstanding field and hospital care for your horse

Serving the greater Auckland area, including Kumeu

Physitis

July Event Location

1 Harness Racing Alexandra Park

4 DSE Taupo Indoor SJ NEC, Taupo

5 DSE Taupo Outdoor XC NEC, Taupo

5 Northgate Lodge Dunstan SJ Day 2 Northgate Lodge

11 Winter Race Day Ellerslie

11 Reyna Mini ODE - Day 1 NEC, Taupo

12 Reyna SJ - Day 1 NEC, Taupo

15 Harness Racing Alexandra Park

15 Race Day Pukekohe Park

19 Northgate Lodge Dunstan SH Day 2 Northgate Lodge

25 Race Day Pukekohe Park

25 Reyna Mini ODE - Day 2 2020 NEC, Taupo

26 Reyna SJ - Day 2 2020 NEC, Taupo

26 Northgate Lodge Dunstan Dressage - Day 2 Northgate Lodge

29 Harness Racing Alexandra Park

between 8 months and 2 years of age. The swelling is firm, round and can be painful and hot to touch. Affected joints get an hourglass appearance (Figure 2), and only in severe cases are the horses lame. Affected horses may walk more on the outside of their foot, as commonly the medial (inside) side of the growth plate is worse affected. The medial, inflamed growth plate then grows less and can cause a varus (“toe in”) conformation which is permanent without intervention.

Treatment may include rest (confinement) and pain relief. It may take 2 weeks to 2 months to settle. Corrective trimming may also need to be done on the side of the physitis. Dietary modification of reduced energy intake and ensuring adequate levels of minerals in the right ratios is important. Most horses have a good prognosis if diagnosed early enough. Severe cases may require surgery and it can be a career limiting condition if an angular limb deformity (ALD) forms. See figures 3, 4, and 5.

www.vetassociates.co.nz

Stable talk: July 2020

We are excited to announce that Alex Fowler has officially joined the surgery team at Vet Associates. Alex hails from Christchurch and spent a lot of time working on a family sheep and beef farm in the MacKenzie country. This led him to Massey University and veterinary school in Palmerston North. During his training he developed a passion for equine surgery which drove him to pursue an internship at Pioneer Equine Hospital in California after graduation. Following his internship Alex completed a residency in equine surgery at North Carolina State University and became a Diplomate of the American College of Veterinary Surgeons in 2020. He is excited to be back in New Zealand and have time on his hands to enjoy the outdoors again!

We welcome another surgeon to the team!

Auckland Area Calendar

» Figure 2. The bell shape of the bone indicated by the arrow is abnormal and due to physitis (large white arrow). The smaller black arrow shows a lytic (black) area in the growth plate, this is abnormal and a sign of inflammation.

» Figure 3. This is the lateral fetlock image of the same joint Figure 2, showing the sclerosis (increased whiteness or density) around the lytic lesion, all are indications of an inflamed physis. This foal was treated with confinement and diet restrictions and was not lame at the time of diagnosis (3 months of age).

» Figure 4 & 5. This is the same foal nearly two months later, you can see the lytic lesion has resolved and there is some sclerosis (increased density/whiteness) still present but less than the previous set of x-rays.