Neoplasms of Domestic Animals in East Africa

Br. uet.

J.

(1968),124,514

NEOPLASMS OF DOMESTIC ANIMALS IN EAST AFRICA By

MA'x

MURRAY

Department of Experimental Veterinary Medicine, University of Glasgow

SUMMARY

Little detailed information has been published on the incidence and types of tumours of animals in East Africa. During 1963 and 1964, a survey of diseases was made on 411 domestic animals presented for post-mortem examination at the University College, Nairobi. In addition, sixty-nine canine biopsy specimens were examined. One hundred and ninety-eight tumours, of which seventy-two were malignant, were found. Several were of interest because of apparent geographical differences in incidence from areas where data were available. These included thyroid, oesophageal, transmissible venereal tumours, squamous cell carcinoma and haemangiosarcoma. INTRODUCTION

Little detailed information has been published on the incidence and types of tumours of animals in East Africa. This knowledge is of obvious importance in comparative studies of the geographical incidence of cancer. During 1963 and 1964, a survey of diseases was carried out on animals, namely dogs, cats and cattle, presented for post-mortem examination by the small and large animal clinics of the Veterinary Faculty, Nairobi. MATERIALS AND METHODS

Two hundred and eighty-six dogs, fifty-three cats and seventy-two bovine animals were presented for post-mortem examination. In addition, there were sixty-nine canine biopsy specimens. The small animals were mainly from the Nairobi area while the bovine animals were from Kikuyu, a region of Africanowned small farms near Nairobi. No data were available on the denominators of the background population of dogs. Many were in good health and were presented only because their owners were leaving Kenya at the time of Independence. It was considered that the dogs used should represent an unselected sample of the population. T able I shows the d enominators of the population sampled. Blocks of tissue for histopathological examination were fixed in corrosive sublimate formol solution (Carleton & Drury, 1957), dehydrated and cleared in an alcohol-amyl acetate-chloroform series and embedded in paraffin wax. Sections were stained routinely with haemalum and eosin.

NEOPLASMS OF ANIMALS IN EAST AFRICA RESULTS

Post-mortem and biopsy material are described separately as the latter must give a biased result in the estimation of the relative incidence of tumours arising from various tissues and organs. Those tumours which are clinically and surgically accessible are most likely to be submitted for examination.

Dogs One hundred and twenty-five tumours were found in eighty-two (29 per cent) of 286 dogs examined post mortem. Of these tumours, eighty-eight were benign, and in thirty-seven dogs malignant tumours were present. Fifty-seven of the biopsy specimens were neoplastic and of these twenty-one were malignant. Tumours are described according to their site of origin. I. Tumours oj the skin and subcutis. Fifteen skin tumours were found in fourteen (5 per cent) dogs on post-mortem examination. Six tumours were malignant and of these two had metastasized (Table II ). One case was a 12 year old bitch TABLE I DENOMINATORS OF POPULATION SAMPLED

Age-

Sex Male Femal e Total Biopsy specim enst

TOlal

l>-4years

5- 12 years

13- di year.r

.')0 30

95

16 q

16 1

81

80 8

'7 6

:10 3

186 (j 9

58

1'25

• Accurate ages were not always known, hence the use of wide classes. t The sex of the animals from which the biopsies were removed was not always recorded, hence tabulation with regard to sex could not be made. TABLE II TUMOURS OF THE SKIN AND SUBCUTIS IN FOURTEEN DOGS

Type Benign

Intermed iate* Malignant

Total No. of tumours

Diagnosis

rear>' 0- 4

Papilloma Perianal adenoma Melanoma H aemangioma Lipoma

0 0 0 0 0

Skin adnexal tumour Mastocytoma

0

Squamous ce ll carcinoma Anaplastic mesenchymal tumour Mastocytoma (multiple)

5- 12

I

0 0 0 0

0

0

2

13- 16

Tolal 2

.,

1 0

2

0

2

0

0

0

10

3

3 2

15

* These tumours are potentially malignant. However, only exceptionally do th ey metastasize although they are moderately invasive. They an: usually amenable to surgica l treatment.

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with a squamous cell carcinoma of the skin of the face. It had infiltrated locally and had metastasized to the regional lymph nodes and the lungs. An anaplastic mesenchymal tumour was found in the skin of the inguinal region of a 12 year old male dog. There was widespread local infiltration and metastatic lesions were found in the inguinal, axillary and sternal lymph nodes, in the spleen, liver and heart. Twenty-four skin tumours were removed from twenty-two dogs (Table III). One squamous cell carcinoma was removed from a male dog of only 2 years of age. 2. Tumours of the female genitalia. Post-mortem examinations revealed tumours of the female genitalia in twenty-one (17 per cent) of 125 bitches (Table IV). In five of the eight mammary carcinomas and in the only sarcoma, metastatic lesions were found. Two of the carcinomas had metastases in the supramammary lymph nodes. In a further two, the supramammary lymph nodes and the TABLE III TUMOURS IN

BIOPSY SPECIMENS OF THE SKIN AND SUBCUTIS IN TWENTY-TWO

rears

Diagnosis

Type

0-4

Benign

Papilloma Perianal adenoma Melanoma Haemangioma Lipoma

0 0 0 0 0

Interm ed iate

Skin adnexal tumour Mastocytoma

I

Malignant

0

Squamous cell carcinoma Sweat ,gland carcinoma Highly anaplastic carcinoma Piloepi thelioma Sebaceous gland carcinoma Fibrosarcoma

Total 1';0. of tumours

5- 12

13- 16

DOGS

Total

0 0 0 0

0 2 2

0 0

3 2

I

5

I

7

0 0

2 2

0 0 0 0 0

2 2

0 0 0

2

21

24

TABLE IV TUMOURS

Site

Mammary gland

OF

THE GEN ITALIA OF TWENTY-ONE BITCHES

Diagnosis

rears 0-4

5- 12

0

5 5

Adenoma Carcinoma Fibrosarcoma

0

Uterus Horn Body

Fibroleiomyoma Fibroleiomyoma

0 0

Vagina

Fibroleiomyoma

0

Total No. of tumours

0

0

13- 16 2

3 0

Total

7 8

2

I

0 2 13

8

21

NEOPLASMS OF ANIMALS IN EAST AFRICA

lungs were involved. In a fifth bitch, metastases were seen in the supramammary axillary and bronchial lymph nodes and in the lungs. Secondary lesions were found in the supramammary and sternal lymph nodes, the lungs and kidneys of the bitch with a mammary fibrosarcoma. Two fibroleiomyomas occurred in the vagina of a 13 year old bitch. These had caused compression and obstruction of the urethra with associated hydronephrosis and pyelonephritis. Fourteen of the sixty-nine biopsies were tumours of the female genitalia (Table V). One of these was a mammary fibrosarcoma. This bitch died 3 months after the biopsy and widespread metastatic sarcomas were found. TABLE V TUMOURS IN BIOPSY SPECIMENS OF THE GENITALIA OF FOURTEEN BITCHES

Site

Years

DiagllOsis

Mammary gland

Vagina

0-4

5 - 12

Adenoma Carcinoma Fibrosarcoma

0 0 0

Transmissible venereal tumour

0

2

0

13

Total No. of tumours

13- 16

7

I

3

0

Total S 3

0 0

2

14

3. Tumours of the male genital tract. Twenty (12.4 per cent) of 161 male dogs had tumours of the genital tract (Table VI). No metastasis or hormonal imbalance was evident in any of the fourteen dogs with testicular tumours. No evidence of metastasis was found in the five dogs with transmissible venereal tumours. However, these caused considerable mechanical discomfort to the dogs concerned. The only malignant tumour was a prostatic carcinoma in an adult dog. In this case there were no metastatic lesions. TABLE VI TUMOURS OF THE MALE GENITAL TRACT IN TWENTY DOGS

Site

DiagllOSis

Tears

0- 4

5- 12

Carcinoma

0

Testicle

Interstitial cell adenoma Seminoma Sertoli cell tumour

o '

6

0

+

Total No. of tumours

Transmissible venereal tumour

0

Total

0

Prostate

Penis/prepuce

13- 16

3 0 0

9 4

4

20

3 15

5

Twelve of the fifteen tumours removed from the male genitalia were transmissible venereal tumours (Table VII).

5 18

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TABLE VII TUMOURS IN BIOPSY SPECIMENS OF THE MALE GENITAL TRACT IN FIFTEEN DOGS

Site

rears

Diagnosis

Testicle

Penis/ prepuce

0-4

5-12

13-16

Total

Interstitial cell adenoma Seminoma Sertoli cell tumour

0 0 0

2 0

0 0 0

2 0

Transmissible venereal tumour

3

9

0

12

3

12

0

15

Total No. of tumours

4. Tumours of the alimentary tract and associated viscera. Eleven tumours, eight of which were malignant, were found in the alimentary tract often (3.5 per cent) dogs (Table VIII). A squamous cell carcinoma of the left tonsil occurred in a 7 year old bitch. Metastatic lesions were present in the left retropharyngeal lymph node. Two osteogenic sarcomas and one fibrosarcoma were found in the terminal part of the oesophagus in each of three dogs. In each case there was conclusive evidence of Spirocerca lupi infections (Murray, Ig68a ). One osteogenic sarcoma occurred in an adult male Boxer and in this case, there were small metastases in the lungs. The other osteogenic sarcoma was found in a 5 year old male Labrador. There were no metastatic lesions. The fibrosarcoma occurred in a 12 year old male Airedale and metastases were present in the regional lymph nodes, lungs and kidneys. TABLE VIII TUMOURS OF THE ALIMENTARY TRACT AND ASSOCIATED VISCERA IN TEN DOGS

Sile Tongue

Diagnosis

rears 0- 4

5-

12

13- 16

Fibropapilloma Degranulated mast ceIllull10ur

0

0

0

()

Tonsil

Squamous cell carcinoma

0

0

Oesophagus

Osteogenic sarcoma Fibrosarcoma

()

0

0

Stomach

Carcinoma

0

0

Fascia ass. with

Fibroleiomyoma

0

2

()

Total

2

()

rectum

Bile duct carcinoma Carcinoma of gall bladder

Li"er Total

::\0.

of tumours

2

()

0

0

0

8

3

II

Of the biopsy specimens examined, two were from the alimentary tract. One found in a 2 year old male dog was a squamous cell carcinoma of the tongue and the other, an adult male dog, had epulids of the gums.

NEOPLASMS OF ANIMALS IN EAST AFRICA

5 19

5. Tumours oj the respiratory tract. Five (2 per cent) dogs were found to have tumours in the respiratory tract. Two of these were anaplastic nasal carcinomas. One occurred in a 13 year old female Pug. In this case the tumour had infiltrated locally into the turbinate bones, the periorbital region and the hard palate, and metastases were found in the lungs. In the other case, a 6! year old male Boxer, the tumour had infiltrated into the turbinates and the left periorbital region, resulting in compression of the eyeball and marked exophthalmos. Bronchial cancer occurred in three dogs. There was no evidence of metastasis in any case. Two of these tumours were found in male dogs, one an adult Spaniel and the other an 8t year old Boxer. The other case occurred in a 15 year old mongrel bitch. 6. Tumours in the urinary tract. Three (I per cent) dogs had tumours in the bladder; all were benign. There was one papilloma, one haemangioma and one fibroleiomyoma. All three occurred in adult male dogs. 7. Tumours oj the brain. Tumours were present in the brains of two (0.7 per cent) dogs. An oligodendroglioma measuring 3 cm. in diameter was found involving the caudate nucleus, the hippocampus and the thalamus in a 9 year old female Boxer. As astrocytoma measuring 1.5 cm. in diameter was found just above the right optic tract and lateral to the cerebral peduncle in a 7 year old male Boxer. Severe neurological signs were observed in both cases. 8. Tumours of the chemoreceptors. Heart base chemodectomas were observed in two (0.7 per cent) dogs. One dog was an I I year old female Boxer and the other was an I I year old male Alsatian. In the first case, the tumour was 4 cm. in diameter and was situated just dorsal to the pulmonary conus at the anterior border of the pulmonary artery, on the left side of the arch of the aorta and the posterior part of the right atrium. There was 40 ml. of blood-stained fluid in the pericardial sac. In the other case, the tumour was I cm. in diameter and was situated in the wedge between the posterior of the pulmonary artery, the left side of the arch of the aorta and the anterior dorsal border of the left atrium. 9. Tumours oj lymphoid tissue. Lymphoid tumours occurred in thirty-four (12 per cent dogs). Thirty-three of these were benign lymphomas of the spleen; three were found in dogs less than 4 years old. One case of multicentric lymphosarcoma occurred in an adult male Fox Terrier. All the superficial lymph nodes were involved as were those of the thorax and abdomen. The spleen, liver and lungs were extensively infiltrated. 10. Tumours qf vascular tissue. Tumours of vascular origin occurred in four (1.4 per cent) dogs and one biopsy specimen. Two of these were malignant. One, in a 15 year old male dog, occurred in the parietal pleura and had metastasized widely to the lungs, liver, kidneys and spleen. In the other case, an adult bitch, the neoplasm appeared to originate in the spleen and had

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metastasized throughout the peritoneal cavity. In addition to the skin haemangioma found in an adult male Bull T errier, one skin biopsy was removed from an adult dog of unrecorded sex. 11. Tumours oj endocrine glands. In fifty-three dogs, aged from 3 years, discrete small yellowish foci were observed in the cortex and medulla of the adrenal gland at post-mortem examination. In some cases, these lesions were single and in other cases they were multiple. There is controversy as to whether such lesions are neoplastic or hyperplastic (Jubb & Kennedy, 1963). In this report they have not been included as neoplasms. In nine (3 per cent) dogs, tumours occurred in the endocrine glands (Table IX). Eight of these tumours were present in the thyroid gland; only one was malignant and metastasized to the lungs. A carcinoma of the right adrenal, found in a 12 year old male, had metastasized to the right thyroid gland and to the posterior vena cava where it had resulted in almost complete occlusion of the vessel and subsequent heart failure. TABLE IX TUMOURS OF ENDOCRINE GLANDS IN NINE DOGS

Site

Diagllosis

Thyroid

0-4

Adenoma Carcinoma Carcinoma

Adrenal cortex

0

Years 5- 12 3

0

0

TOlal

7

4 0 0

0

Total No. of tumours

13-16

5

4

9

Biopsy was performed on two thyroid carcinomas. One occurred in a 7 year old bitch and the other in a 12 year old bitch. 12. Tumours ojthe skeletal system. An osteogenic sarcoma was found in the ribs of a 9 year old female Doberman Pinscher.

TABLE X NEOPLASMS FOUND IN THE CAT

Age

Sex

9 years 7 years Adult· Aged· Adult·

Not recorded F Not recorded Not recorded F

Liver Liver Liver Liver Mammary gland left 1

Bile duct carcinoma Bile duct carcinoma Bile duct carcinom a H epatoma Carcinoma

14 years

M castrate

Ski n

Sweat gland carcinoma

Site

• Accura te ages were not known .

Diagllosis

Metastases None Lungs None :\lone Sternal and axillar y lymph nodes, lungs, parietal pleura, kidneys Lungs

NEOPLASMS OF ANIMALS IN EAST AFRICA

521

Cats Neoplasms were found in six (I I per cent) of the fifty-three cats examined post mortem (Table X). Severe jaundice was present in a 9 year old cat with a bile duct carcinoma, and 100 ml. of straw-coloured fluid was recovered from the abdomen of a 7 year old cat also with a bile duct carcinoma. Cattle Of the seventy-two cattle examined post mortem, tumours were found in ten (14 per cent) (Table XI). Five of the eight malignant tumours were squamous cell carcinomas; these tumours showed marked local infiltration but no metastases were found. One animal with a history of persistent haematuria and a terminal packed cell volume of 10 per cent was found to have haemangiosarcoma of the bladder; there were no metastases. TABLE XI TUMOURS FOUND IN CATTLE

Site Vulva

Eyelid

Diagnosis

NIetastases

Breed

Age

Sex

Squamous cell carcinoma Squamous cell carcinoma

Massive local infiltration Massive local infiltration

European

Adult

F

European

Adult

F

Squamous cell carcinoma

Local invasion with emboli in lymphatics and blood vessels Local infiltration

European

Adult

F

European

Adult

F

Local infiltration

European

Aged

M

Squamous cell carcinoma Squamous cell carcinoma Skin

Adnexal tumour (basal cell type) Haemangioma

None

European

Adult

F

None

European

Adult

F

Rectum

Fibrosarcoma

Local infiltration

European

Adult

F

Bladder

Haemangiosarcoma

Multiple lesions in bladder

European

Adult

F

Thyroid

Carcinoma

European Multiple lesions descending the neck

Adult

M

DISCUSSION

The incidence of neoplastic disease in comparison with other diseases was high in the population of dogs examined (Murray, Ig68b), tumours being found in approximately 30 per cent of the dogs. Within the confidence intervals of the small sample the results of this survey may indicate the relative incidence of the more important tumours of the dog in Kenya. From the comparative point of view, the main interest of a survey of this kind is in locating any obvious differences in incidence from areas where documented information is available. However, valid comparisons could not be

522

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made because most of the major tumour surveys done in dogs (Feldman, 1932; Jackson, 1936; Mulligan, 1949; Plummer, 1956; Cotchin, 1959) were carried out on highly selected populations, cases being submitted because of the presence or suspected presence of tumour. In addition, in these surveys a large percentage of tumours examined was from biopsy specimens. It is likely that those tumours which are clinically and surgically accessible are more commonly submitted for examination. In this survey, a number of tumours of particular interest were found . The relative incidence of thyroid tumours-5.5 per cent of all tumours found- was high in comparison with the findings of the surveys previously referred to. This was notable as thyroid hyperplasia, often considered a precancerous lesion (Moulton, 1961 ), was not found. Three malignant sarcomas occurred in the terminal part of the oesophagus; evidence of S. lupi was present in each case. The association between this nematode and sarcomas of the oesophagus was first reported by Seibold et al. (1955). Evidence of spirocercosis was found in ninety-four (33 per cent) of the 286 dogs examined post mortem in this survey (Murray, 1968a). Transmissible venereal tumour was one of the most common tumours found. Of the twelve tumours in dogs less than 4 years old, four were transmissible venereal tumours, one occurring in an 8 month old male Pointer. This tumour is readily transmissible using intact cells but attempt'! to transmit the tumour using material from viable cells have failed. Neither by ordinary cytological nor by electron microscopical methods could any evidence be adduced for the origin of the cell type involved. It is possible that this "tumour" is in fact a long-standing transplantable cloned cell line and preliminary work indicates that it may have an unique karyotype. The relative incidence of squamous cell carcinoma- ten (25.6 per cent) of thirty-nine skin tumours- was high in comparison with Cotchin (1959) who found seventy-six (4.8 per cent) present in a series of 1572 skin tumours in dogs in Great Britain. Of the ten tumours found in cattle, five were squamous cell carcinomas; three of these were associated with the eyelids and two with the vulva. Solar radiation is said to be largely responsible for skin cancer in humans exposed to the sun for many years (Evans, 1966). It has also been incriminated as a predisposing factor in squamous cancer of eyelids in cattle (Guibert, Wahid, Wagnon & Gregory, 1948; Anderson, Lush & Chambers, 1957), and squamous cancer of the vulva in cattle (Burdin, 1964). Solar radiation might also be related to the high incidence of squamous cancer found in Kenyan dogs examined in this survey. In the cats examined, it was of interest that four of the six tumours found were primary liver tumours. The occurrence of a haemangiosarcoma in the bladder of a bovine animal was notable as most of the tumours found in the urinary tracts of domestic animals are of epithelial origin (Moulton, 1961). Sharp (1967, personal communication) working in the same laboratory as the author carried out post-mortem examinations on an additional six cattle with haemangiosarcomas

NEOPLASMS OF ANIMALS IN EAST AFRICA

of the bladder. All seven cases described came from an upland district in which the condition enzootic bovine haematuria, as d escribed by K alkus (1939) and Plummer (1944), was well r ecogn ized . Both these workers d escribed epithelial and angiom atous changes in the bladders of affected animals. Pamukcu (1955, 1957) found bladder tumours in association with this condition. The ae tiology of these bladd er tumours is unknown . Olson, Pamukeu and Brobst (1965) recovered a papilloma-like virus from tumours of the bovine urinary bladder. Pamukcu, Goksoy & Price (1967) were able to induce t umours of both epitheli al a nd vasoformative tissue in the bladder of bovine a nimals fed with bracken fern (Pinis aql! ilina ). A C KNOWLEDGMENTS

I would like to record my thanks for mu ch guidance and the facilities provided by Professor 'V. F. H.Jarrett, Professor \\T . I. M . McIntyre and Dr ' V. B. Martin of the U niversity of Glasgow. I also wish to thank Mrs H eather Campbell of the D epartment of Veterinary M edicine and Surgery, University College, Nairobi . REFERENCE S

ANDERSON, D . E., L USH, J. L. & CHAMBERS, D. ( 1957). J. Anim. Sci., 16, 739, 1007. BURDIN, M. L. ( 1964). R es. vet. Sci., 5, 497. CARLETON, H . M. & D RURY, R. A. B. ( 1957). H istological T echnique, 3rd edn , p . 23 . Oxford University Press. COTCHIN, E. ( 1959) . Vet. R ec., 71 , 1040. EVANS, R. WINSTON ( 1966 ) . H istological Aj}jlearallces qf Tum ours. 2nd edn p. 887. Edinburgh & Lond on : E. & S. Livingstone. FELDMAN, W. H . ( 1932). N eoj}lasJll.< qf D omesticated Animals. Philadelphia a nd London: W. B. Saunder s. GUIBERT, H . R ., W AHID, A., W AGNON, K . A. & GREGORY, F. V\'. ( I948 ).J. Anim. Sci., 7, 426. JACKSON, C. ( 1936). Onderstepoort J. vet. Sci ., 6, 3. JUBB, K . V. F . & K ENNEDY, P. C. ( 1963). Pathology of Domestic Animals, Vol. I , p. 337. New York an d London: Acad emic Press . KALKUS, J. W . ( 1939). Vet. Med., 34, 476. MOULTON, J. E. ( 196 1) . Tumours ill D omestic Animals. Berkeley: University of California Press. M ULLIGAN, R. M . ( 1949) . Neoplasms of the Dog. Baltimore: Williams and Wilkins. MURRAY, M. ( I968a). J. comj) . Path. Ther. (in press) . M URRAY, M . ( I968 b). Bull. epizoot. D is. Afr. , 16, 21. OLSON, C ., PAM UKCU, A. M. & BROBST, D . F. ( 1965). Callcer R es., 25, 840. PAM UKCU, A. M. ( 1955). Zentb l. VetMed., 2, 409. PAMUKCU, A. M. ( 1957) . Zentbl. VetMed. , 4, 185. PAMUKCU, A. M., GOKSOY, S. K . & PRICE, J . M. ( 1967) . Cancer R es., 27 ( I ), 917. PLUMMER, P.J. G. ( 1944) , Can.J. compo M ed., 8 (6), 153. PLUMMER, P . J . G. ( 1956) . Can. J . compo NEed. , 20, 239. SEIBOLD, H . R ., BAILEY, V\'. S .. HOERLEIN, B. F ., JORDAN, E. M. & SCHWABE, C. ( 1955). Am. J. vet. R es., 16, .' j. (Accepted for jmblicatioll 27th Feb ruary 1968)

Neoplas lDes des anitnaux dOlDestiques d' Afrique orientale (Murray) ResUlDe. Jusqu'ici, o n a public pe u de re nseignements d e tailles sur les cas et types d e tumeurs des animaux d' Afrique o ri e ntal e. Au cours d es ann ees 1963 e t 1964, on e ffec tua, au College

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universitaire de Nairobi, une etude des maladies de 411 animaux domestiques, soumis a un examen post-mortem. De plus, on fit la biopsie de soixante-neuf specimens canins. On trouva cent quatre-vingt-dix-huit tumeurs, dont soixante-douze etaient malignes. Plusieurs d'entre elles presentaient un certain interet, a cause des differences geographiques apparentes dans les cas provenant de regions ou il etait possible d'obtenir des donnees. Les neoplasmes en question comprenaient des tumeurs thyroides, oesophagiennes, veneriennes transmissibles, Ie carcinome et l'hemangiosarcome des cellules squameuses. Neoplaslnen bei Haustieren in Ostafrika

(Murray) Zusalnlnenfassung. Es liegen nur wenige detaillierte Angaben tiber Auftreten und Typus von Tumoren bei Tieren in Ostafrika vor. 1963/64 wurde eine Untersuchung auf Krankheiten von der Universitat Nairobi an 411 Haustieren durchgeftihrt, die flir postmortem-Untersuchungen eingeliefert wurden. Ausserdem wurden 69 caninus Biopsien vo·r genommen. Es wurden 189 Tumore festgestellt, davon 72 maligne. Einige waren wegen der offensichtlichen geographischen Unterschied zu Gegenden, tiber die genaue Unterlagen erhaltlich sind, interessant. Dazu gehoren u.a. Thyroid-, Oesophageal-, Venerealtumore, squamose Zellencarcinome und Haemangiosarcoma. Neoplaslnas de anilnales dOlnesticos en Africa Oriental

(Murray) ResUlnen. Poca informaci6n detallada se ha publicado sobre la incidencia y los tipos de los tumores de los animales en el Africa Oriental. Durante los afios 1963 y 1964, se llev6 a cabo un estudio de las enfermedades en 411 animales domesticos presentados en el Solegio Universitario de Nairobi para su examen despues de la muerte. Ademas, se examinaron sesenta y nueve ejemplares de biopsia canina. Se encontraron ciento noventa y ocho tumores, de los cuales setenta y dos eran malignos. Varios de ellos eran de interes, por presentar, al parecer, unas diferencias geograficas en la incidencia en comparaci6n con las zonas sobre las que habias datos disponibles. Figuraban entre ellos tumores tiroideos, esofagicos y venereos transmissibles, asi como carcinoma celular escamoso y hemangiosarcoma.