Vitamin D and Alpacas
The Importance of Vitamin D Supplementation in Alpacas
By Sarah Donahoe August 21, 2013
Revision May 2018 and March 2019
Over the past several years, I have seen firsthand, the importance of vitamin D supplementation and unfortunately, the consequences of vitamin D deficiency. In the most severe form of vitamin D deficiency, commonly referred to as rickets, problems include permanent deformities, bone fractures and ultimately death if not corrected in time. Additionally, well-meaning owners can cause harm by overdosing with vitamin D in hopes of counteracting the downward spiral of vitamin D deficiency.
Vitamin D is an essential vitamin and critical for bone growth and development. It is one of the fat soluble vitamins (A, D, E and K) which means they are stored in the body and thus have the potential for causing toxic side effects with high levels. Vitamins B & C are water soluble and for the most part do not cause toxicity, although in humans you can have a neuropathy from excessively high levels of one of the B vitamins. In the simplest of terms, Vitamin D is activated by sun exposure. In South America, alpaca's exposure to sunlight and resultant vitamin D absorption is much higher than in US. Think higher elevation and thus thinner atmosphere.
Early signs of Rickets are trouble with their gait as seen in this video. Examples include not stretching out fully when walking, short striding, crouching, slower to move and get up and less likely to get up when approached. Alpacas will lie around more, even grazing in an area lying down. Rickets is painful. Crias stop growing. Limbs will eventually become "deformed" meaning incorrect angulation will occur. Hind quarters start to cow sickle, and you might see sickle-hock. Calf-kneed in the front, buck-kneed or knock-kneed also in the front. The alpaca will appear unsteady, which they are, and will walk with their hind legs crossing under them. They don't run.
My first encounter with vitamin D deficiency was several winters ago. That winter was particularly gloomy and my Fall crias presented with subtle gait changes. They looked like they were in pain, took on a crouch appearance, and were less active. This was particularly noticeable in the darker animals. We started them on vitamin D injections and their symptoms began to subside within a week. At that point we instituted a vitamin D protocol on our farm.
Several years ago, I boarded a female with a 7 month cria at side. The two had been living on extremely poor quality hay, straw like in appearance and probably in nutritional value. At the time the cria was in full fleece and it was both very dense and very long. Amber (pictured here) was the size of a 1-2 month old cria. She weighed somewhere in the area of 35 pounds. She basically did not walk and nibbled while laying in an abnormal kush position. Amber was in a great deal of pain and was pre-ruminant. She was no longer able to stand under her mom to nurse because of the pain and instability. She required vitamin D injections every two weeks, blood draws to monitor her levels, BoSe, Vitamin B injections, Banamine and Meloxicam for pain, joint supplements with glucosamine/chondroitin, and oral feeding via drench gun with whatever concoction I could make for her. Her abdomen was very large, probably due to a stretched C1 from eating the poor quality hay and filling up her vault. Paradoxically, she could only take in 3 oz at a feeding of goat's milk. It was a long road to recovery but today, Amber has recovered. Her rehabilitation took 5 months. She is no longer on pain medicines. Her front legs have permanent deformities. Fortunately, she has not grown to her full adult weight, so her joints do not need to support that additional weight.
We had another cria board at our farm this past spring. Born last Fall, this cria is dark brown and weighed 35 pounds at the age of 7 months. She was given vitamin D injection upon arrival but even so, she soon started showing signs of lameness and lack of activity. We aggressively started treatment for vitamin D deficiency and today she is thriving. She has gained 25 pounds over 3 months and is pain free, running, and has a normal gait and conformation. She is not on any medications other than the vitamin D she will receive this Fall and Winter.
Diagnosis can frequently be made on clinical presentation. “A rickets syndrome in juvenile llamas and alpacas characterized by a shifting leg lameness and enlargement of the joints, most noticeably the carpus, has been described. Affected crias have variably shown a slowed growth rate, reluctance to move, and kyphosis. Radiographic evidence of abnormal growth plates and low serum phosphorus concentrations were consistent with a diagnosis of rickets. Radiographic evidence of abnormal growth plates and low serum phosphorus concentrations are consistent with a diagnosis of rickets.”
Robert J. Van Saun, DVM, MS, PhD, DACT, DACVN was a lead investigator of The Camelid Research Group at Oregon State University that investigated the role of vitamin D in hypophosphatemic rickets over a period from 1993 to 1999. Below are their findings.
1. Serum vitamin D and consequently serum P concentrations vary according to season with lowest values during the winter months. Fall-born crias will need to be carefully managed and vitamin D supplemented to prevent the rickets syndrome.
2. Vitamin D deficiency induces low serum phosphorus concentration in growing llamas and alpacas resulting in a hypophosphatemic syndrome. Supplementation of vitamin D can increase both vitamin D and phosphorus status
3. Intramuscular injection of commercial vitamin D preparations at a dosage between 1500-2000 IU/kg (700-900 IU vitamin D/lb) body weight can effectively increase serum vitamin D concentrations for 90 days. For a product containing 75000 IU/ml of Vitamin D, this is equivalent to 0.9 to 1.2 ml/100 lb body weight dosage. These injections can be used to treat a clinical animal or used to boost vitamin D status in an effort to prevent the problem. Preventive treatment should be given in the Fall.
4. Llamas and alpacas are seemingly tolerant of acute vitamin D toxicity. However evidence is present that higher doses of vitamin D may result in altered P metabolism with the possibility of Ca and P precipitation in urine and tissues. Vitamin D supplementation should be approached carefully and under the guidance of a veterinarian. We do not recommend increasing the suggested treatment dosage of vitamin D as there is no evidence of improved effect and suggestions of deleterious effects to animal health are evident.
5. Preliminary estimates suggest that llamas and alpacas require a daily supplementation of vitamin D at a rate of 33 IU/kg body weight (15 IU/lb body weight) to maintain sufficient serum concentrations of vitamin D to prevent rickets. This is much higher than observed for other species (6.6 IU/kg body weight), but are consistent with previous findings of lower vitamin D availability and support the clinical observation of greater vitamin D problems in llamas and alpacas compared to other species.
Poor nutrition is a contributing factor. Alpacas need good quality hay. This doesn't mean high protein hay, but hay with a good TDN (Total Digestible Nutrients) and RFV (Relative Feed Value). RFV should be 95-105 and TDN 55-65.
For Rickets and when administering vitamin supplements aggressively, monitor Vitamin D and Phosphorus blood levels. Consider Vitamin D supplementation in situations with any prolonged illness. It's one of my first line drugs, especially in those slow to grow and Failure to Thrive (FTT) crias.
My protocol for vitamin D deficiency and suspected rickets is vitamin D injection every 2 weeks, 500 IU per kg IM until I get the Vitamin D level up to normal range. They are started on pain meds, usually Banamine injectable SQ daily or BID to control pain. After several days, you can switch to Meloxicam which is given as a 2 mg/kg loading dose then 1mg/kg every day or every other day. Most recently, I have used Adequan injectable with marked improvement in mobility of cria with rickets. Adequan contains polysulfated glycosaminoglycan at 100 mg/ ml. Adequan belongs to a class of drugs called Disease Modifying Osteoarthritis Drugs (DMOAD). It is the only FDA-approved product of its type, and has been clinically shown to help treat arthritis while simultaneously relieving joint pain.
Protonix can be used empirically if concerns regarding stomach ulcers in C3. Protonix is administered IV or SQ at 1mg/kg injectable, once a day. Treatment is also aimed at correcting malnutrition if present. If I think gut absorption for nutrition is a real problem, I give them frozen colostrum, 1cc/kg daily orally for several weeks. As vitamin D is also accompanied by nutrition deficiencies, I consider that the cria is probably deficient in selenium and I administer BoSe once SQ. Administer vitamin B injectable to crias not chewing their cud. Depending on how long or how stunted their growth, I might add Thyroid-L, usually 3-4 mg daily. There are numerous caloric supplements to improve weight gain but I approach weight gain slowly as to not place additional stress on compromised joints.
Prevention is key. I start administering injectable Vitamin D to those less than 2 years of age in October every year and continue every two months through and including the March dose. If it's a gloomy winter, everyone, regardless of age, gets Vitamin D injections. Vitamin D can be administered orally as well. However giving oral medications to ruminants can result in erratic absorption rates from the gut.
Vitamin D injections can cause soreness at the injection site. Read the label for correct dosing. Vitamin D injectable is compounded into different concentrations so always dose according to IU per kg.
Vitamin D in Camelids: The Whole Story, Robert J. Van Saun, DVM, MS, PhD, DACT, DACVN, Proceedings for GALA meeting.