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.

An investigative study into the copper content of cat foods in the USA* discovered an association between clinical signs of copper deficiency and copper oxide as a source of copper in some commercial foods.

Copper is an essential trace element which has many roles in the body, including foetal development but clinical reports of copper deficiency in small animals are rarely reported. The true incidence of copper deficiency may be higher than currently recognised if :

• Veterinarians are unaware of the clinical signs associated with copper deficiency 
• Pet foods containing recommended amounts of  copper use copper oxide as a source and actually result in poor copper status
• Convenient laboratory methods for determining copper status are not reliable in cats

Signs associated with copper deficiency include the following :

• Poor body weight at birth
• Neonatal death
• Abnormal coat colour - black hair turns rusty brown 
• Collagen defects leading to distortion of the limbs, curling of the tails

In the USA 3 commercial cat foods containing copper oxide as a source of copper were found to contain adequate concentrations of copper (as recommended by the National Research Council) but kittens born to queens consuming these foods developed the above signs of deficiency.

In addition, cats fed twice the NRC requirements of copper oxide have a lower conception rate, and take longer to conceive than cats fed twice the NRC recommendation of copper sulphate.

These findings suggest that clinicians should be aware that clinical signs of copper deficiency can occur when cats are fed rations containing more than the recommended amount of copper if the source of copper in the food is copper oxide

The authors of this study also looked at various methods of assessment of copper status in cats and reached the following conclusions.

• Plasma copper concentrations - NOT reliable in cats
• Plasma extracellular superoxide dismutase concentrations - NOT reliable in cats
• Plasma ceruloplasmin concentrations - NOT reliable in cats
• Liver copper concentrations - reliable - but an invasive biopsy technique is required
• Hair analysis using latest technology may be reliable

NB The change of black hair to brown hair is also associated with amino acid deficiency : phenylalanine or tyrosine - both of which are necessary for melanin formation.

Provet Feedback Request

Provet would like to hear from you if you have seen a confirmed case of copper deficiency in cats or dogs. Please send full clinical details to feedback@provet.co.uk 

Thank You 

Reference

*Morris J.G. & Fascetti A.J. (1998) Dietary copper intake in the queen : Influences on reproduction and lack of cuproenzyme response. Win Foundation Study, University of California, Davis, California

Updated January 2016