You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Apart from the dubious claim that it fends off Vampires - what benefits do pets get from garlic supplements ?

Garlic is an interesting Asian alliaceous plant which has a strong pungent smell and taste. It is widely used in cooking, in fiction helps to fend off vampires and over the years it has been claimed to have many beneficial actions in medicine.

In herbalism Garlic is believed to have antiviral and antiparasitic effects, and in Chinese Medicine it has been used for the treatment of cryptococcal meningitis.

Most of the health benefits claimed for garlic are anecdotal and not proven by conventional scientific studies. However in some scientific publications it has been reported to have certain benefits in humans :

• Reduces total cholesterol in the blood
• Reduces triglyceride (fat) concentrations in the blood
• Increases high density lipoproteins (HDL) in the blood
• Has an antithrombotic effect

In one 12 week study a small number of HIV patients given garlic showed an improvement in T4:T8 cell ratio and increased natural killer cell activity...which are beneficial  as these indicate improved immune status.

In veterinary medicine little serious scientific attention has been given to garlic, even though it has been used for many years and there are many products freely available for sale which purport to give health benefits to animals :

"GARLIC - This is often employed by farriers as a remedy for coughs and thickness of wind " A Treatise on Veterinary Medicine" by James White 1826

Products on the market now claim to prevent infections, worms and fleas. Some also claim to be effective in treating rheumatism.

It was rumoured for many years that garlic could be used to acidify urine - but when it was tested in cat food⁵ - the patients urine increased from a pH of 6.7 to 7.1 - the opposite effect.

The approximate chemical analysis of garlic cloves is as follows*  :

Garlic is particularly high in potassium content containing 620mg/100g. It also has an inverse calcium:phosphorus ratio containing 19mg calcium/100g and 170 mg phosphorus/100g. Garlic contains relatively high concentrations of the amino acid Tryptophan (1.9mg/100g) but no vitamin D or vitamin B_12.

Provet Recommendations

There may be health benefits for pets  in garlic, but so far they have not been proved. When scientific research has looked critically at the claims made for garlic they have usually been found to be untrue. However, not all claims have been rigorously tested. 

Provet's recommendation is - do not rely on unsubstantiated claims for the health benefits of garlic. eg do not rely on garlic powders to treat worms. Seek the advice of your veterinarian for the most efficient treatments.

However, giving small amounts of garlic probably does no harm -unless an individual is prone to develop high blood potassium (called hyperkalaemia) in which case garlic should be avoided.

References

1. Raiten D.J. (1990) Nutrition and HIV Infection. Center for Food Safety and Applied Nutrition  FDA. Washington. Contract 223-88-2124
2. Abdullah T et al. (1989) Garlic as an antimicrobial and immune modulator in AIDS. Proceedings of the Fifth International Conference on AIDS  p 466, Montreal
3. Fulder S. Garlic and the prevention of cardiovascular disease  (1989) Cardiology in Practice 7(3): 30-35
4. Mansell P and Reckless J (1991) Garlic. British Medical Journal 303 : 379.
5. Lewis L.D et al.(1987)  Small Animal Clinical Nutrition III p9-27
6. *McCance and Widdowson's The composition of Foods 5th edition (1991) . Pubished by the RSC and MAFF.

Updated October 2013