Condition guide

Hypothyroidism in Dogs: Diagnosis, Treatment & Prognosis

Reviewed by Dr. Ravi Baraiya, B.V.Sc. & A.H.Updated 26 Oct 202610 sources

Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]

In dogs, hypothyroidism should be diagnosed by integrating the history, clinical symptoms, and thyroid hormone assay, and the diagnosis should be confirmed through a specific evaluation of the thyroid gland rather than a low T4 concentration alone. ^[1]^[2]^[4]

In dogs, the treatment of hypothyroidism is lifelong, daily oral thyroid hormone replacement, and prognosis for return to normal function following adequate treatment is excellent in most adult hypothyroid dogs. ^[9]^[10]

Key points

Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
In dogs, diagnosis of hypothyroidism is based on clinical signs such as lethargy, weight gain, obesity, and coat changes, as well as low serum thyroid hormone concentrations. ^[9]
In most adult hypothyroid dogs, prognosis for return to normal function following adequate treatment is excellent. ^[10]

Overview

Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]

Causes & risk factors

Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
In dogs, the most common cause of hypothyroidism is lymphocytic thyroiditis that is an autoimmune inflammatory disorder caused by the presence of thyroglobulin auto antibodies. ^[5]
Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]

Clinical signs

In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
Affected dogs have a slow onset of decreased activity, cold intolerance, and skin changes of thickening and mild hyperpigmentation. ^[4]
Affected dogs have a slow onset of decreased activity, cold intolerance, and skin changes of thickening and mild hyperpigmentation. ^[4]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]

Diagnosis

In dogs, because of the vague clinical signs and the absence of specific abnormalities on a routine blood test, the diagnosis of hypothyroidism should be confirmed through a specific evaluation of the thyroid gland. ^[1]
Affected dogs have a slow onset of decreased activity, cold intolerance, and skin changes of thickening and mild hyperpigmentation. ^[4]

Test or finding	Interpretation
Low total T4 concentration alone	The diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
Low total T4 plus high TSH	If the TSH concentration is high, hypothyroidism can be diagnosed. ^[2]
Low total T4 plus low fT4	If the fT4 is low, a diagnosis of hypothyroidism can be made. ^[2]
Low total T4 plus fT4 within reference range	Hypothyroidism cannot be diagnosed, and the clinician should consider other differentials for the dog’s clinical signs. ^[2]
Normal TSH	A normal TSH concentration does not exclude the diagnosis because 13% to 38% of hypothyroid dogs have normal TSH concentrations. ^[2]
T3 concentrations	T3 concentrations vary widely and are not diagnostically useful. ^[2]
Serum thyroxine (T4)	The easiest and best documented thyroid hormone assay is serum thyroxine (T4). ^[4]
TSH stimulation test or thyroid gland biopsy	The most accurate diagnosis is made using either the thyrotropin (TSH) stimulation test or thyroid gland biopsy. ^[4]

In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
Approximately 20–40% of dogs with hypothyroidism have a low TT4 and low fT4 but a normal TSH concentration. ^[6]
In dogs, the most common cause of hypothyroidism is lymphocytic thyroiditis that is an autoimmune inflammatory disorder caused by the presence of thyroglobulin auto antibodies. ^[5]
Approximately 20–40% of dogs with hypothyroidism have a low TT4 and low fT4 but a normal TSH concentration. ^[6]
Approximately 20–40% of dogs with hypothyroidism have a low TT4 and low fT4 but a normal TSH concentration. ^[6]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]

Differential diagnoses

Approximately 20–40% of dogs with hypothyroidism have a low TT4 and low fT4 but a normal TSH concentration. ^[6]
Approximately 20–40% of dogs with hypothyroidism have a low TT4 and low fT4 but a normal TSH concentration. ^[6]
Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
In dogs, diagnosis of hypothyroidism is based on clinical signs such as lethargy, weight gain, obesity, and coat changes, as well as low serum thyroid hormone concentrations. ^[9]

Treatment

In dogs, diagnosis of hypothyroidism is based on clinical signs such as lethargy, weight gain, obesity, and coat changes, as well as low serum thyroid hormone concentrations. ^[9]
In dogs, the most common cause of hypothyroidism is lymphocytic thyroiditis that is an autoimmune inflammatory disorder caused by the presence of thyroglobulin auto antibodies. ^[5]
Approximately 20–40% of dogs with hypothyroidism have a low TT4 and low fT4 but a normal TSH concentration. ^[6]
In dogs, the most common cause of hypothyroidism is lymphocytic thyroiditis that is an autoimmune inflammatory disorder caused by the presence of thyroglobulin auto antibodies. ^[5]

Drug	Species	Dose	Route	Frequency
Sodium levothyroxine (L-thyroxine)	Dogs	0.01–0.02 mg/kg	PO	q 12–24 hours ^[8]
thyroxine	Dogs	30--50 mcg/kg/day		in 2 divided doses ^[4]

In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]

Monitoring

Approximately 20–40% of dogs with hypothyroidism have a low TT4 and low fT4 but a normal TSH concentration. ^[6]
Approximately 20–40% of dogs with hypothyroidism have a low TT4 and low fT4 but a normal TSH concentration. ^[6]
In dogs, diagnosis of hypothyroidism is based on clinical signs such as lethargy, weight gain, obesity, and coat changes, as well as low serum thyroid hormone concentrations. ^[9]
Approximately 20–40% of dogs with hypothyroidism have a low TT4 and low fT4 but a normal TSH concentration. ^[6]
Approximately 20–40% of dogs with hypothyroidism have a low TT4 and low fT4 but a normal TSH concentration. ^[6]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, diagnosis of hypothyroidism is based on clinical signs such as lethargy, weight gain, obesity, and coat changes, as well as low serum thyroid hormone concentrations. ^[9]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
In dogs, hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. ^[3]
After the dosage is stabilized in dogs, serum T4 concentrations should be checked 1–2 times per year. ^[9]
Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
In dogs, diagnosis of hypothyroidism is based on clinical signs such as lethargy, weight gain, obesity, and coat changes, as well as low serum thyroid hormone concentrations. ^[9]
Hypothyroidism is a common endocrine disease of dogs, and the diagnosis should never be based on low T4 concentration as a sole finding. ^[2]
In dogs, diagnosis of hypothyroidism is based on clinical signs such as lethargy, weight gain, obesity, and coat changes, as well as low serum thyroid hormone concentrations. ^[9]

Prognosis

In most adult hypothyroid dogs, prognosis for return to normal function following adequate treatment is excellent. ^[10]

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Medically reviewed by

Dr. Ravi Baraiya, B.V.Sc. & A.H.

Veterinarian · Reviewed 26 Oct 2026

References

Canine Hypothyroidism: Update on Diagnosis and Treatmentwww.vin.com · by S Daminet
Passage read from this source
Diagnosis of Canine Hypothyroidism Because of the vague clinical signs and the absence of specific abnormalities on a routine blood test, the diagnosis should be confirmed through a specific evaluation of the thyroid gland. As always, laboratory results should be interpreted in the light of history and physical examination findings. A thorough clinical examination of the patient, knowledge of the advantages and disadvantages of all available tests and knowledge of the factors that can influence the results, will allow the veterinarian to correctly diagnose the disease. The table below contains a summary of the advantages and disadvantages of the most commonly used thyroid hormone tests in dogs. Table. Advantages and disadvantages of the most commonly used thyroid tests.
Canine Hypothyroidism: Diagnosis and Treatmenttodaysveterinarypractice.com · Feb 11, 2019
Passage read from this source
Hypothyroidism is one of the most common endocrine disorders in dogs, but it is often misdiagnosed. Here’s how to ensure you make the correct diagnosis. February 11, 2019 | Issue: March/April 2019
Hypothyroidism is a common endocrine disease of dogs. It occurs when the thyroid glands fail to produce adequate amounts of the hormones thyroxine (T4) and triiodothyronine (T3). Primary hypothyroidism resulting from idiopathic thyroid gland atrophy or immune-mediated lymphocytic thyroiditis is the most common diagnosis. Uncommon causes of canine hypothyroidism include congenital disease resulting from dyshormonogenesis of thyroid hormone, abnormal thyroid-stimulating hormone (TSH) production, or abnormal thyroid gland development.1 Thyroid hormones are involved in a wide variety of metabolic processes, and low thyroid hormone levels result in a constellation of clinical signs and laboratory abnormalities that characterize hypothyroidism. Multiple hormone tests are required to make a diagnosis. The diagnosis should never be based on low T4 concentration as a sole finding.
When a dog suspected to have hypothyroidism has a low total T4 concentration, fT4 and/or TSH concentrations must be evaluated to help confirm or refute the diagnosis (**TABLE 1**). If the TSH concentration is high, hypothyroidism can be diagnosed. However, 13% to 38% of hypothyroid dogs have normal TSH concentrations,10-12,25 so a normal TSH concentration does not exclude the diagnosis. Because of this limitation, it is often helpful to evaluate fT4 and TSH simultaneously as confirmatory tests. If the fT4 is low, a diagnosis of hypothyroidism can be made. If T4 is low and fT4 is within reference range, hypothyroidism cannot be diagnosed, and the clinician should consider other differentials for the dog’s clinical signs. T3 concentrations vary widely and…
Treatment failure is uncommon. Possible reasons for failure to achieve the targeted T4 concentration include owner noncompliance in administering medication or patient refusal to swallow the pills. Variable gastrointestinal absorption of levothyroxine is also considered to be a possible cause.28 If a target post-pill T4 concentration has been achieved and clinical signs are not controlled, the dosing frequency should be increased to twice daily. Additionally, the diagnosis of hypothyroidism should be reconsidered. If the diagnosis of hypothyroidism is definitive and the dog’s T4 concentration is well controlled, consider whether a concurrent disorder could be causing clinical signs. Dogs are generally resistant to the effects of excessive levothyroxine supplementation. However, clinical signs such as polyuria/polydipsia and hyperactivity may develop.26
Canine Hypothyroidism: Overview, Diagnosis, Treatmentwww.cliniciansbrief.com
Passage read from this source
- Hypothyroidism onset is often insidious, and subtle signs may have been present for months or years prior to diagnosis. Signs are typically seen after 75% of thyroid function has been lost.20,21 - Common signs associated with reduced metabolism include weight gain and obesity, lethargy, weakness, cold intolerance or heat-seeking behavior, and mental dullness. - Dermatologic changes are common and occur in up to ≈80% of cases (see Dermatologic Signs).20,21 - Diarrhea and constipation occur more commonly in hypothyroid dogs as compared with euthyroid controls.22 - Neurologic dysfunction occurs in ≈6% to 29% of cases and often resolves within 2 months following levothyroxine supplementation.19,23 - Peripheral neuropathy is the most common manifestation, especially in large breeds, and may result in…
- Autoantibodies against T4 may falsely increase tT4 results, while those against T3 may decrease tT3 results on most assays. Therapeutic Trial - Levothyroxine, a synthetic T4, may be used in patients with consistent clinical signs or biochemical abnormalities, no other significant illness, and/or equivocal test results. - Owners should be instructed to monitor a specific clinical sign or lesion for improvement during the trial. - Some conditions may appear to respond to supplementation in euthyroid dogs, which could delay diagnosis of the actual comorbidity. - If a clinical response is evident, therapy should be discontinued and the patient observed for recurrence. If signs recur, hypothyroidism is confirmed. Drug Interference With Thyroid Testing
- Another goal of therapy is to normalize an elevated TSH concentration (if increased at time of diagnosis). - Clinical improvement (eg, improved energy level) is typically noted soon after treatment initiation. - Lack of improvement within 1 to 2 weeks should prompt re-evaluation of diagnosis and/or investigation into presence of other comorbidities. - Weight loss and dermatologic changes improve slowly and may take several months to fully resolve. - Alopecia may initially worsen after treatment initiation due to retained hairs being expelled as hair follicles restart growth cycles; however, signs of new hair growth are typically noted within the first month of treatment. - Neurologic changes may initially improve rapidly, but full resolution can take several months.
- Management of hypothyroidism includes tailoring options to match the needs and/or resources of the patient and pet owner. Although high-level care involves definitive diagnostics, screening for other comorbidities, and frequent therapeutic drug monitoring, some owners may decline additional testing beyond a tT4 concentration. - Measurement of fT4 by equilibrium dialysis is often the most expensive aspect of a thyroid panel. A cost-effective alternative is consideration of clinical signs in combination with a tT4 and TSH concentration. - When diagnostic options are limited, a treatment trial based on high clinical suspicion alone may be warranted. - Treatment without appropriate diagnostics should ideally be avoided because the cost of treatment with monitoring is expensive over time, and inappropriate diagnosis may lead…
The diagnosis and treatment of canine hypothyroidismpubmed.ncbi.nlm.nih.gov
Passage read from this source
Hypothyroidism in dogs should be diagnosed by integrating the history, clinical symptoms and thyroid hormone assay. Affected dogs have a slow onset of decreased activity, cold intolerance, and skin changes of thickening and mild hyperpigmentation. The hair coat becomes dry and coarse, and alopecia develops in friction areas. The non-specific clinico-pathological changes of a mild anaemia and hypercholesterolaemia do not occur consistently. The easiest and best documented thyroid hormone assay is serum thyroxine (T4). The most accurate diagnosis is made using either the thyrotropin (TSH) stimulation test or thyroid gland biopsy. The condition is controlled by thyroxine replacement therapy at a dose rate of 30--50 mcg/kg/day in 2 divided doses, for the life of the dog.
Incidence, complications and therapeutic evaluation of clinical ...pmc.ncbi.nlm.nih.gov
Passage read from this source
Hypothyroidism is a relatively common condition in dogs compared to other diseases causing dermatological changes or obesity in dogs. Therefore, it must be considered for early diagnosis and treatment before encountering complications that could be life threatening for dogs. Keywords: Complications, Dermatological changes, Dogs, Hypothyroidism, Levothyroxine, Obesity
Diagnosis of hypothyroidism depends on the observation of any of the specific clinical signs of hypothyroidism, followed by measurement of thyroid hormone level that represented by increased serum concentrations of thyroid stimulating hormone (TSH) and decreased T4 concentration [6, 7]. Levothyroxine (LT4) has long been regarded as the standard treatment for hypothyroidism. When taken orally, this medication is effective, has a prolonged serum half-life that allows for once-daily dosing, and typically leads to the resolution of hypothyroidism symptoms in most patients [8]. Therefore, this study was designed to screen the occurrence of clinical hypothyroidism in different breeds of dogs, suffering from dermatological changes or being obesity. Moreover, we track the cases for detecting complications in severely affected hypothyroid dogs and…
Hypothyroidism has been considered one of the most common endocrine disorders in dogs during the past few years, difficult in diagnosis but very easy to be treated. Definitive diagnosis of hypothyroidism in dogs requires presence of the characteristic features of the disease and using of thyroid function diagnostic tests which may be difficult to interpret due to presence of non-thyroidal illness or recent drug administration, so any animal having one of these characters was excluded from the study [3]. This study aimed to detect the incidence of clinical hypothyroidism among cases suffering from dermatological changes or obesity which are considered the most common clinical signs of hypothyroidism in dogs.
The most common cause of hypothyroidism is lymphocytic thyroiditis that is an autoimmune inflammatory disorder caused by the presence of thyroglobulin auto antibodies. In this study, TgAA were positively detected in seven hypothyroid dogs. Its measurement was used to investigate within reference interval TT4 concentrations in dog strongly suspected to be hypothyroid as interference from TgAA give false normal TT4 [18]. In addition, TgAA measurements are crucial for identifying autoimmune thyroiditis, a common underlying cause of primary hypothyroidism in dogs [7]. Based on clinical signs and the results of diagnostic tests, the diagnosis of hypothyroidism is confirmed in affected dogs, as previously reported [7, 9, 18].
Canine Hypothyroidism Categorical Approach to Diagnosis ...www.aaha.org · Apr 12, 2023
Passage read from this source
- Approximately 20–40% of dogs with hypothyroidism have a low TT4 and low fT4 but a normal TSH concentration.15,16 However, this scenario could also indicate nonthyroidal illness, so additional testing such as assessing for the presence of antithyroid autoantibodies or a TSH response test can be run to help confirm diagnosis, although these tests may be cost-prohibitive for some clients.24 - Initiate treatment with twice-daily levothyroxine supplementation (ideally on an empty stomach to maximize absorption). - Monitor therapy based on clinical improvement and serial TT4 testing. Assess a TT4 level 4–6 hr post morning pill 4 wk after starting medication or after dose adjustments until control is achieved, then every 6–12 mo as indicated. - Consider monitoring TSH level until…
Clinical Presentation Group 2 dogs have no symptoms of hypothyroidism and a decreased TT4 on routine laboratory screening. Next Steps - It is critical to consider the dog’s signalment, such as age and breed, before proceeding with additional testing for hypothyroidism. Clinically normal dogs of certain breeds such as greyhounds, Alaskan sled dogs (particularly when racing), shar peis, salukis, and deerhounds are routinely reported to have TT4 concentrations that are lower than established laboratory reference ranges. The guidelines task force recommends using breed-specific reference ranges when interpreting hormone levels in these breeds, especially if no clinical signs are present.25
Clinical Presentation Group 3 dogs have a similar clinical presentation to Group 1 dogs, but the TT4 does not confirm hypothyroidism. Next Steps - Investigate for other causes of clinical presentation by reviewing history with client and pursuing additional diagnostics. - Perform an fT4ed with TSH and consider additional testing to rule out thyroiditis, specifically assessing for the presence of antithyroid autoantibodies. Dogs with thyroiditis can have antibodies that falsely elevate TT4 levels because of cross-reactivity of the T4 autoantibodies. Signs of hypothyroidism can develop slowly over time in some of these dogs.3 - A TSH response test could be considered if the TT4 or fT4 concentrations are in the low-normal reference range and the patient lacks circulating antithyroid antibodies.
- Dogs should be treated with supplementation if the diagnosis is confirmed, and therapy is monitored as described for Group 1. However, if the TT4 concentration was within reference range at diagnosis owing to the presence of T4 autoantibodies, an fT4ed is the preferred test to accurately monitor therapy. The 2023 AAHA Selected Endocrinopathies of Dogs and Cats Guidelines are generously supported by Boehringer Ingelheim Animal Health, IDEXX, Merck, Zoetis, and Zomedica. Close
Understanding and diagnosing canine hypothyroidismwww.dvm360.com · Oct 18, 2021
Passage read from this source
The TSH test is used in combination with low TT4 and/or fT4 test results to support a diagnosis of hypothyroidism.
How I Treat Hypothyroid Dogs - WSAVA 2018 Congress - VINveterinarypartner.vin.com
Passage read from this source
Oral sodium levothyroxine (L-thyroxine) is the treatment of choice for long-term management of hypothyroidism. The dose is 0.01–0.02 mg/kg PO q 12–24 hours.
Hypothyroidism in Animals - Endocrine System - Merck ...www.merckvetmanual.com
Passage read from this source
Full Review: May 2024 ByJohanna Heseltine, DVM, MS, DACVIM, Texas A&M University | Peer reviewed byJoyce Carnevale, DVM, DABVP, College of Veterinary Medicine, Iowa State University Last updated: May 2025 v3270909 View the Pet Owner Version Hypothyroidism is the condition that results from thyroid hormone deficiency. Diagnosis is based on clinical signs such as lethargy, weight gain, obesity, and coat changes, as well as low serum thyroid hormone concentrations. The treatment is lifelong, daily oral thyroid hormone replacement. - Etiology| - Clinical Signs| - Diagnosis| - Treatment| - Key Points| - For More Information| - | Hypothyroidism results from thyroid hormone deficiency and is most common in dogs but also develops rarely in other species, including cats, horses, and other…
After appropriate levothyroxine supplementation, improvement in clinical signs should be used to assess the response to treatment. Improvement in lethargy and mentation should occur within 2 weeks. If treatment is unsuccessful, therapeutic monitoring of T4 concentration should be performed to identify the cause of treatment failure. Because an incorrect diagnosis is the most common cause of treatment failure, the clinician should be prepared to withdraw treatment and pursue other diagnoses. In cats, hypothyroidism can also be diagnosed on the basis of finding low to low-normal serum concentrations of total T4 and free T4, with high serum TSH concentrations. A feline-specific TSH assay is available, and the canine TSH assay has also been used to test for feline hypothyroidism.
After the dosage is stabilized, serum T4 concentrations should be checked 1–2 times per year. Free T4 and TSH concentrations will also normalize; however, monitoring of these is often not required. Thyrotoxicosis is rare in dogs and can result in polyuria and polydipsia, weight loss, panting, nervousness, or tachycardia. Treatment failure is uncommon. If clinical signs of hypothyroidism remain despite achieving the target T4 concentrations with levothyroxine supplementation, an alternate diagnosis should be considered.
Canine Hypothyroidism - WSAVA2011www.vin.com
Passage read from this source
Prognosis Prognosis for return to normal function following adequate treatment is excellent in most adult hypothyroid dogs. Prognosis in myxoedema coma is dependent on early diagnosis and puppies with congenital hypothyroidism have variable resolution of clinical signs, being more complete if treatment was started early.

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