By: Sheila Hamilton-Andrews, MSc CCAB

Website:www.dogandcatbehaviour.co.uk

Hypothyroidism is a clinical syndrome that results from a deficiency of thyroid hormones, which in turn results in a generalised slowing down of the metabolic processes and change in behaviour. Not to be confused with hyperthyroidism, which is consequence of excessive thyroid action.

Dogs suffering from hypothyroidism may exhibit one or a combination of symptoms and it is important to recognise that in many cases a change in behaviour may be observed before the more common physical symptoms are presented. Such changes tend to surprise owners, as there has been no apparent incident that could have resulted in the change. For example, any dog that suddenly exhibits unprovoked aggression, having previously been docile and friendly, should be tested for hypothyroidism, if only to eliminate the condition as a possible cause of the aberrant behaviour.

Behaviour Disorders often presented by hypothyroid dogs

  • Dog to dog Aggression (Fight)
  • Dog to Dog Aggression (Flight)
  • Dog to Human Aggression (Fight)
  • Dog to Human Aggression (Flight)
  • Territorial Aggression
  • Irritability
  • Mood Swings
  • General Fearfulness
  • Separation Anxiety
  • Thunder Phobia
  • Noise Sensitivity
  • Shyness
  • Hyperactivity
  • Low Concentration Span
Unprovoked aggression can be the result of canine hypothyroidism (photo from: epuppypottytraining.com)

Unprovoked aggression can be the result of canine hypothyroidism (photo from: epuppypottytraining.com)

Physical Symptoms of Canine Hypothyroidism

  • Weight Gain
  • Fatigue
  • Cold intolerance
  • Loss of Hair
  • Change of hair texture
  • Dry Skin
  • Hard Black spots on skin (Coliderms)
  • Reproductive Disorders
  • Muscular Problems
  • Eye Problems
  • Recurrent infections
  • Heart disease
  • Gastric disorders
  • Loss of smell

Any dog can suffer from hypothyroidism regardless of gender, there being no evidence to suggest that it is more prevalent in females than males. It used to be thought it was a disease of middle age but is now being seen in much younger dogs, especially those breeds that are predisposed to the condition, Irish Setters, Golden Retrievers, Boxers, Dalmatians, Cocker Spaniels, Bearded Collies and Old English Sheepdogs being but a few.

Hypothyroidism being a familial, inheritable disease, breeders should test any breeding bitch or stud dog prior to mating and refrain from using any dog that tests positive in order to prevent it passed down through the generations.

Hypothyroidism is a treatable condition so if you are concerned that your dog may be suffering from this condition please contact your vet.

All images in this article were obtained from Google Images

Weight gain in hypothyroid dog (photo from: biologicnr.com

Weight gain in hypothyroid dog (photo from: biologicnr.com

Hair loss in hypothyroid dog (photo from: vet.uga.edu)

Hair loss in hypothyroid dog (photo from: vet.uga.edu)

Typical Rat Tail in a hypothyroid dog (photo from: research.vet.upenn.edu)

Typical Rat Tail in a hypothyroid dog (photo from: research.vet.upenn.edu)