PULMONARY METASTASIS OF CANINE MAMMARY TUMOR IN A GOLDEN RETRIEVER

PULMONARY METASTASIS OF CANINE MAMMARY TUMOR

IN A GOLDEN RETRIEVER

 

S.R Rotoro1, Royama Sari1, Erni Sulistiawati1, Cucu K. Sajuthi1

1. 24 HRS Veterinary Clinic Drh. Cucu K. Sajuthi and Associate

Ruko Nirwana Sunter Asri Tahap III Blok J-1 no.2 Sunter, North Jakarta-Indonesia

Keywords: Canine Mammary Tumor, Dog, Golden Retriever, Lungs, Metastasis

 

INTRODUCTION

 

Mammary neoplasms in dogs are second in frequency after skin tumors and they are the most common types of tumors in the bitch. According to the histological diagnosis, between 41 and 53 % of the mammary tumors that occur in the bitch are considered malignant5. Mammary neoplasms primarily affect older animals with a mean age of about 10 years. Most affected animals are intact females or females that have undergone ovariectomy late in life. Mammary tumors are rare in males and in young animals of either sex3.

Early ovariohysterectomy is strongly protective against the development of mammary tumors2,3. Bitches neutered before the first estrous cycle are at no greater risk for mammary tumor than are males. After 2.5 years of age or after the second estrous cycle, ovariohysterectomy is no longer protective in bitches3.

 

MATERIALS AND METHODS

 

       The observation was done on a 10 years old, intact female Golden Retriever dog which had mammary tumor metastasized to the lungs. Signalment and medical history of the dog were evaluated.  Physical examination was performed, supported by laboratory test including complete blood count (CBC) and serum biochemical profile (SBP). Radiographic examination was also performed to evaluate the presence of metastatic tumors to the lungs. The positioning of the dog was right lateral recumbent and dorsoventral (sternal recumbent) Diagnostic images of the thorax confirmed pulmonary metastasis of mammary tumor that was suspected on the basis of the history and physical examination. Therapy chosen for the dog was palliative. The dog’s condition was observed for two months before the dog died. Then, a necropsy and histopathology examination were performed.

 

RESULTS AND DISCUSSION

 

A 10 years old, intact female Golden Retriever dog was examined at the 24 HRS Veterinary Clinic Drh. Cucu K. Sajuthi and Associate on January 21st 2009. The third left mammary gland was firm and enlarged less than 5 cm in diameter. Cytologic evaluation revealed mammary lobular hyperplasia. This condition is common in intact bitches without any significant symptoms and can develop to be malignant.

A year later on February 25th 2010, the dog was brought again to the clinic. The caudal mammary glands including 3 mammary glands on the left and 1 on the right, were significantly enlarged. Complete blood count (CBC) and serum biochemical profile (SBP) were analyzed, and showed all values within reference range. The surgical excision was chosen to remove the tumor and also the four mammary gland adjacent to the tumor. The surgery was performed on March 13th 2010.

The tumor was noticed to regrow very rapidly within three months, followed with locally suppurative inflammation (pus) and some ulceration (Fig. 1). Abdominal respiration was also observed in this dog, and we then decided to redo the diagnostic test including thoracal radiograph (Fig. 2), CBC and SBP, as shown in Table 1. Based on the thoracal radiograph, known that the tumor metastasized to the lungs and led to worse prognosis.

The dog survived for 5 months post surgery before the animal condition declined slowly and the animal died on August 4th 2010. A necropsy was performed and we found masses of tumor in the lungs (Fig. 3). Histopathology examination revealed papillary cystadenocarcinoma which spread to the lungs and the spleen. This case study reported that the progression of canine mammary tumor can be very aggressive.

Canine mammary tumor is very related with hormonal factors. It is well established that dogs spayed before their first estrous cycle have a greatly reduced risk of developing mammary tumor. The risk of developing mammary tumors, approximately 50% of which are malignant, rises from nearly 0% in dogs spayed prior to their first estrus to 26% for dogs that are spayed after their second estrus1. Mammary tumors primarily affect middle-aged (9 to 11 years) female intact dogs, with an increased incidence beginning at approximately 6 years of age. Sexual steroid hormones (estrogen and progesterone) are thought to have their primary effect on target cells during the early stages of mammary carcinogenesis in dogs4. Early ovariohysterectomy is strongly protective against the development of mammary tumors2,3.

pulmonary1

Fig.1. Mammary tumor was notice to regrow very rapidly within 3 months, followed with locally suppurative inflammation (pus) and some ulceration

Table 1

Result of diagnostic tests including thoracal radiograph, CBC and SBP

Date

Features

Abnormal Result

June 24th 2010

CBC Leukocytosis (WBC 51.0 x 109/L), nonregenerative anemia (RBC 4.59 x 106/µL, Hb 10.7 g/dL, HCT 32.2%), granulocytosis (46.4 x 109/L)
SBP AST 71 U/L, total protein 8.3 g/dL, ALP 536 U/L
Radiograph Pulmonary metastasis suspected

June 28th 2010

CBC Leukocytosis (WBC 33.8 x 109/L), nonregenerative anemia (RBC 4.19 x 106/µL, Hb 9.2 g/dL, HCT 28.5%), granulocytosis (23.2 x 109/L)
SBP Total protein 7.9 g/dL

July 6th 2010

CBC Leukocytosis (WBC 24.6 x 109/L), nonregenerative anemia (RBC 3.9 x 106/µL, Hb 8.7 g/dL, HCT 26.9%), granulocytosis (20.5 x 109/L)

July 7th 2010

Radiograph Diffuse miliary pulmonary metastasis

pulmonary2

Fig. 2.  Diagnostic images of the thorax; (A). Dorsoventral; (B). Right lateral recumbent Fig. 3. Pathological finding revealed masses of tumor nodules in the dog’s lungs

 

REFERENCES

 

[1]   Henry CJ. 2007. Chemical, Physical, and Hormonal Factors. In: Withrow and Macewen’s Small Animal Clinical Oncology. Anthony Winkel, Shelly Stringer, editor. St. Louis: Saunders Elsevier Inc.p16.

[2]   Misdorp W. 2002. Tumors of the mammary gland. In: Tumors in Domestic Animals. Meuten DJ, editor. New York: Iowa State Pr.

[3]   Nelson RW, Couto CG. 2003. Small Animal Internal Medicine. 3rd ed. St. Louis: Mosby Inc.

[4]   Perez Alenza MD, Pena L, del Castillo N et al. 2000. Factors influencing the incidence and prognosis of canine mammary tumours, J Small Anim Pract 41:287.

[5]   Rezaie A, Tavasoli A, Bahonar A, Mehrazma. 2009. Grading in canine mammary gland carcinoma. J. Biol. Sci. 9:333-338.

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