Hypothyrodism (low thyroid)
There is more than one form of thyroid disease, but the more commonly diagnosed forms include lymphocytic thyroiditis or idiopathic thyroid gland atrophy. There is also Congenital Hypothyroidism with Goiter.
From the AKC Canine Health Foundation:
Despite a sufficient understanding of the mechanisms underlying acquired canine hypothyroidism, diagnosis of the disease is not straightforward and remains one of the greatest challenges in veterinary medicine. Age, breed and systemic illness all affect thyroid hormone concentrations, and clinical signs of hypothyroidism are often indistinguishable from other diseases. As such, veterinarians and breeders know that hypothyroidism is commonly over-diagnosed in the dog. CHF is pleased to announce the funding of a new grant that will investigate three novel diagnostic methods that investigators believe will provide a more accurate diagnosis than the currently available tests.
Symptoms: Low levels of T3 and T4 hormones, lethargy, weight gain, dermatitis, alopecia, temperature sensitivity.
If untreated, seizures, coma, death.
Treatment Options: Thyroid replacement hormone by veterinary prescription. Prognosis is very good, but pet will require daily thyroid hormone supplements for the rest of it’s life..
Known Mode of Inheritance: Unknown in Cardigans, but there has been a demonstrated pattern of inheritence, with some pedigrees at greater risk. Identified as an inherited Autosomal Recessive in other breeds.
Age of onset: <2, typical age of diagnosis 5-7 years old.
- Cardigan: yes
- Pembroke: yes
- Other Breeds: yes, many breeds including mixed breeds.
Incidence in Cardigans: Uncertain due to low participation in testing. OFA Thyroid Statistics ranks cardigans 45th out of the 93 breeds with more than 50 individuals submitted to their database. Out of the 52 OFA thyroid evaluated Cardigans to date (the lowest number of all breeds on the list), 94.2 percent (50 individuals) have been identified as ‘normal’ and 3.8 percent (2 individuals) were diagnosed with Autoimmune Thyroiditis.
- Cardigans: no
- Other breeds: yes
- Active?: yes, Spanish Water Dogs only
Registry: yes, the OFA provides an open Thyroid registry. OFA Thyroid registry information
Tests Available: yes, a phenotype test evaluating thyroid function can be done. See above link to the OFA for information. Best time to conduct this test to identify autoimmune antibodies may be between the ages of 2-5 years.
DNA markers have been identified in other breeds and tests may be available or in development for them, but DNA testing is currently unavailable for Cardigans.
- Molecular Basis of Congenital Hypothyroidism with Goiter in Spanish Water Dogs
- Determination of Breed-Specific Reference Ranges for Assessing Thyroid Function in Several Breeds
- Performing a whole genome screen on Rhodesian Ridgebacks with thyroglobulin antibody positive hypothyroid disease
- Collecting a Second Cohort of Hypothyroid Dogs
Published papers and Articles
- Increased genetic risk or protection for canine autoimmune lymphocytic thyroiditis in Giant Schnauzers depends on DLA class II genotype.
- The NCBI lists several hundred additional articles related to canine hypothyroidism.